Biodiversity, Ecology, and Natural History of Polychaetous Annelids from the Gulf of Mexico

Michael G Reuscher

Polychaetes are abundant and ecologically important benthic organisms, yet their diversity and phylogenetic relationships are far from being resolved. The purpose of my dissertation was to measure their diversity in the Gulf of Mexico and to compare polychaete assemblages of different regions, depths, and sampling periods. Furthermore, I studied the natural history of the diverse polychaete family Paraonidae. The polychaete diversity of the Gulf of Mexico was examined using a comprehensive species database. Species were assigned to ecological, morphological, and biogeographical categories and each category’s contribution was examined throughout different depths and regions. Spatial and temporal comparisons of polychaete assemblages were conducted at three transects on the northern Gulf of Mexico continental slope. Phylogenetic relationships within the family Paraonidae were studied based on the examination of type material. Polychaete diversity changed with depth. The shelf break was accompanied by a steep change in the species composition. The southeastern Gulf had the most distinct polychaete fauna. Endemism was at 10%; in the deep-sea more than 30% of the species were endemic and the relative contribution of carnivorous species doubled. At the continental slope, abundance did not continuously decrease with depth between 350 and 1500 m, but dropped between 1500 and 2100 m. Abundance in the spring was approximately twice as high as in the fall, in depths up to 1500 m. Polychaete assemblages changed continuously with increasing depth. Short-term temporal changes of polychaete assemblages had reversed in the long run. In the cladistic analyses, monophyly of Paraonidae was supported. Its synapomorphies are the complete fusion of prostomium and peristomium and the dorsal location of the anus. Cirrophorus and Paradoneis should be considered synonyms. The prostomial antenna, which was used to distinguish both genera, is a homoplastic character. Two species of Paradoneis are being moved to a new genus. Spatial and temporal patterns of polychaete diversity in the Gulf of Mexico were discovered. Additional sampling efforts are needed for a more complete picture of the diverse polychaete fauna. The phylogenetic analyses based on morphology resolved important issues. However, additional genetic markers are needed to uncover sister species relationships.

BIODIVERSITY, ECOLOGY, AND NATURAL HISTORY OF POLYCHAETOUS ANNELIDS FROM THE GULF OF MEXICO A Dissertation by MICHAEL G. REUSCHER Diploma in Biology, Ruprecht-Karls-Universität Heidelberg, Germany, 2008 Submitted in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY in MARINE BIOLOGY Texas A&M University-Corpus Christi Corpus Christi, Texas December 2013 UMI Number: 3606905 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI 3606905 Published by ProQuest LLC (2013). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, MI 48106 - 1346 © Michael Gerhard Reuscher All rights reserved December 2013 BIODIVERSITY, ECOLOGY, AND NATURAL HISTORY OF POLYCHAETOUS ANNELIDS FROM THE GULF OF MEXICO A Dissertation by MICHAEL G. REUSCHER This dissertation meets the standards for scope and quality of Texas A&M University-Corpus Christi and is hereby approved. Thomas C. Shirley, PhD Chair John W. Tunnell, Jr., PhD Co-Chair Frank L. Pezold, PhD Committee Member Anja Schulze, PhD Committee Member Kim Withers, PhD Committee Member Lauren Cifuentes, PhD Graduate Faculty Representative JoAnn Canales, PhD Dean, College of Graduate Studies December 2013 ABSTRACT Biodiversity, Ecology, and Natural History of Polychaetous Annelids from the Gulf of Mexico December 2013 Michael G. Reuscher, Dipl.-Biol., Ruprecht-Karls Universität Heidelberg (Germany) Chair of Advisory Committee: Dr. Thomas C. Shirley Co-chair of Advisory Committee: Dr. John W. Tunnell, Jr. Polychaetes are abundant and ecologically important benthic organisms, yet their diversity and phylogenetic relationships are far from being resolved. The purpose of my dissertation was to measure their diversity in the Gulf of Mexico and to compare polychaete assemblages of different regions, depths, and sampling periods. Furthermore, I studied the natural history of the diverse polychaete family Paraonidae. The polychaete diversity of the Gulf of Mexico was examined using a comprehensive species database. Species were assigned to ecological, morphological, and biogeographical categories and each category’s contribution was examined throughout different depths and regions. Spatial and temporal comparisons of polychaete assemblages were conducted at three transects on the northern Gulf of Mexico continental slope. Phylogenetic relationships within the family Paraonidae were studied based on the examination of type material. Polychaete diversity changed with depth. The shelf break was accompanied by a steep change in the species composition. The southeastern Gulf had the most distinct polychaete fauna. Endemism was at 10%; in the deep-sea more than 30% of the species were endemic and the relative contribution of carnivorous species doubled. v At the continental slope, abundance did not continuously decrease with depth between 350 and 1500 m, but dropped between 1500 and 2100 m. Abundance in the spring was approximately twice as high as in the fall, in depths up to 1500 m. Polychaete assemblages changed continuously with increasing depth. Short-term temporal changes of polychaete assemblages had reversed in the long run. In the cladistic analyses, monophyly of Paraonidae was supported. Its synapomorphies are the complete fusion of prostomium and peristomium and the dorsal location of the anus. Cirrophorus and Paradoneis should be considered synonyms. The prostomial antenna, which was used to distinguish both genera, is a homoplastic character. Two species of Paradoneis are being moved to a new genus. Spatial and temporal patterns of polychaete diversity in the Gulf of Mexico were discovered. Additional sampling efforts are needed for a more complete picture of the diverse polychaete fauna. The phylogenetic analyses based on morphology resolved important issues. However, additional genetic markers are needed to uncover sister species relationships. vi DEDICATION In dedication to my family, whose love and support for me is deeper than the vast ocean that lies between us. vii ACKNOWLEDGEMENTS This dissertation was a tremendous endeavor, which I could not have achieved all by myself. I would like to thank my advisor Dr. Thomas Shirley, whose guidance, encouragement, and patience were crucial during this five-year-long journey. Dr. Shirley stands out not only as a well-rounded naturalist, but also as a person. I will always fondly remember our road trip to Florida and the submersible dives off British Columbia, during which we were piloting “Deep Workers”, among many other good memories. Dr. Wes Tunnell took over as the co-chair of my committee when Dr. Shirley retired in February 2012. He has been very helpful and encouraging ever since. Whenever I had a request or issues to be solved, Dr. Tunnell was always there to help immediately – no matter if he was in his office or in a remote place on one of his many research trips. My committee members, Dr. Frank Pezold, Dr. Anja Schulze, and Dr. Kim Withers have been integral in helping me pinpoint the details of my research projects and they are thanked for dedicating their time to my committee meetings, qualifying exams, defense, and reviews of my dissertation. Dr. Lauren Cifuentes is thanked for serving on my committee as Graduate Faculty Representative. The former and current MARB program coordinators, Dr. Greg Stunz and Dr. Mike Wetz, have been helpful guides for navigating through the program requirements. My former advisor from Heidelberg University (Germany), Dr. Volker Storch, encouraged me to contact Dr. Shirley and to apply for a PhD position at Texas A&M University – Corpus Christi. Without him, my life would have taken a different turn. The same is true for my two other former advisors from Germany, Dr. Dieter Fiege (Senckenberg Research Institute and Natural History Museum Frankfurt) and Dr. Thomas Wehe (Heidelberg University), who have awakened my fascination for polychaetes. viii I sincerely thank the many administrative persons at the Harte Research Institute, the College of Science & Engineering, the College of Graduate Studies, and several other university departments that ensured that I was able to focus on my research. Karin Griffith and Ana Billeaux from the Office of International Education are also thanked for exercising the American motto “E pluribus unum”, by helping international students through the process of integration, and encouraging the exchange of diverse cultures. I am grateful for the teaching assistantships by the College of Science & Engineering between the fall semester of 2008 and the spring semester of 2011, the research assistantship under Dr. Paul Montagna between the fall semester of 2011 and the fall semester of 2013, and the MARB summer research scholarships for the summer semesters 2010-2013. I thank all my friends that I have found over the last five years. Amongst the high workload and the constant pressure of deadlines that comes with the commitments of a PhD student, they kept me sane, encouraged me, cheered me up when necessary, and made my life enjoyable. Among all sacrifices, the toughest one has been the separation from my family and friends in Germany, and missing out on important events in their lives. My thoughts have always been with my parents, Gerhard and Gerda Reuscher, my sister Stefanie Mangei, my brother-inlaw Tobias Mangei, and their kids Tim, Zelia, and Theresa, my grandma Elisabeth Speicher, my deceased grandparents, my uncle and aunt Gerhard and Vildan Speicher with their kids Denis and Chiara, and my good friends in Germany. None of them has ever complained about my absence but always encouraged me to achieve this great goal. Finally, I thank my wife Adela for her love, patience, and encouragement. I am blessed to have you in my life! ix Many other persons have helped and supported me during specific research projects. Their contributions are acknowledged in the respective chapters of my dissertation. x TABLE OF CONTENTS CONTENTS PAGE ABSTRACT .....................................................................................................................................v DEDICATION .............................................................................................................................. vii ACKNOWLEDGEMENTS ......................................................................................................... viii TABLE OF CONTENTS ............................................................................................................... xi LIST OF TABLES ....................................................................................................................... xiv LIST OF FIGURES .......................................................................................................................xv INTRODUCTION ...........................................................................................................................1 CHAPTER I: Diversity, Distribution, and Zoogeography of Benthic Polychaetes in the Gulf of Mexico .............................................................................................................................................7 Abstract ......................................................................................................................................7 Key words ..................................................................................................................................7 Introduction ................................................................................................................................8 Materials & Methods ...............................................................................................................10 A) Definition of geographic areas and depth classes .....................................................10 B) Analyses ....................................................................................................................12 C) Functional groups......................................................................................................14 D) Biogeographical categories .......................................................................................16 E) Abbreviations ............................................................................................................17 Results ......................................................................................................................................17 A) Species richness analysis ..........................................................................................17 B) Comparative analysis of the Gulf of Mexico polychaete biodiversity .....................27 C) Distribution of functional groups ..............................................................................31 D) Biogeographic affinities of the Gulf of Mexico polychaete fauna ...........................38 Discussion ................................................................................................................................45 A) Species richness analysis ..........................................................................................45 B) Comparative analysis of the Gulf of Mexico polychaete biodiversity .....................47 C) Distribution of functional groups ..............................................................................48 D) Biogeographic affinities of the Gulf of Mexico polychaete fauna ...........................50 xi E) Outlook and recommendations .................................................................................53 Acknowledgments....................................................................................................................54 References ..............................................................................................................................137 CHAPTER II: Spatial and Temporal Dynamics of Polychaete Assemblages on the Northern Gulf of Mexico Continental Slope .......................................................................................................147 Abstract ..................................................................................................................................147 Key words ..............................................................................................................................148 Introduction ............................................................................................................................148 Materials & Methods .............................................................................................................150 Results ....................................................................................................................................155 A) Abundance ..............................................................................................................155 B) Diversity..................................................................................................................161 Discussion ..............................................................................................................................175 A) Abundance ..............................................................................................................175 B) Diversity..................................................................................................................181 Conclusion .............................................................................................................................183 Acknowledgements ................................................................................................................184 References ..............................................................................................................................186 CHAPTER III: Cladistic Analysis of the Family Paraonidae (Annelida: Polychaeta) and the Genera Cirrophorus and Paradoneis Based on Morphological Characters ................................192 Abstract ..................................................................................................................................192 Key words ..............................................................................................................................193 Introduction ............................................................................................................................193 A) Biology and ecology of Paraonidae ........................................................................193 B) Taxonomic history of Paraonidae ...........................................................................194 C) Morphology and taxonomy of Cirrophorus and Paradoneis .................................195 D) Phylogenetic hypotheses tested...............................................................................197 Materials & Methods .............................................................................................................197 A) Common abbreviations ...........................................................................................197 B) Material examined ..................................................................................................198 C) Taxonomic remarks based on type material examinations .....................................198 D) Phylogeny of Paraonidae ........................................................................................202 a) Taxa included ...................................................................................................202 b) Characters used for cladistic analysis ..............................................................202 c) Analysis............................................................................................................206 E) Phylogeny of Cirrophorus and Paradoneis ............................................................208 a) Taxa included ...................................................................................................208 xii b) c) Characters used for cladistics analysis .............................................................208 Analysis............................................................................................................211 Results ....................................................................................................................................215 A) Cladistic analysis of the family Paraonidae ............................................................215 B) Cladistic analysis of the genera Cirrophorus and Paradoneis ...............................217 Discussion ..............................................................................................................................221 A) Cladistic analysis of the family Paraonidae ............................................................221 B) Cladistic analysis of the genera Cirrophorus and Paradoneis ...............................222 Conclusion .............................................................................................................................225 Acknowledgements ................................................................................................................225 References ..............................................................................................................................227 SUMMARY .................................................................................................................................238 APPENDIX ..................................................................................................................................242 BIOGRAPHICAL STATEMENT ...............................................................................................246 xiii LIST OF TABLES TABLES PAGE TABLE 1.1 Geographical and depth records, data on ecological guilds, and worldwide distribution of Gulf of Mexico polychaetes…………….……………………………………….. 55 TABLE 2.1 p-values of ANOVAs on polychaete abundance at C transect stations of different sampling periods……………………………………………………………………………….. 158 TABLE 2.2 p-values of ANOVAs on polychaete abundance at E and MT transect stations of different sampling periods……………………………………………………………………....161 TABLE 2.3 p-values of ANOSIMs on polychaete diversity at C and E transect stations of different sampling periods……………………………………………………………………... 165 TABLE 2.4 Results of the SIMPER analysis. List of polychaete families most characteristic for each station and sampling period………………………………………………………………. 166 TABLE 2.5 Results of the SIMPER analysis. List of polychaete families that contribute most to the dissimilarity between sampling periods……………………………………………………. 170 TABLE 3.1 List of specimens examined for the cladistic analysis of the Cirrophorus – Paradoneis species complex, including the outgroup taxa…………………………………….. 199 TABLE 3.2 Character matrix for the genus level analysis of Paraonidae………………….….. 207 TABLE 3.3 Character matrix for species level analysis of the genera Cirrophorus and Paradoneis……………………………………………………………………………………... 212 TABLE 3.4 Recommended taxonomic classification of the Cirrophorus – Paradoneis species complex, in comparison to the previous taxonomic classification…………………………….. 224 xiv LIST OF FIGURES FIGURES PAGE FIGURE 1.1 Map of the Gulf of Mexico with color coded bathymetry and sector boundaries… 11 FIGURE 1.2 Polychaete species number per family in the entire Gulf of Mexico……………... 19 FIGURE 1.3 Polychaete species number per family in the northeastern sector………………… 20 FIGURE 1.4 Polychaete species number per family in the northwestern sector………………... 21 FIGURE 1.5 Polychaete species number per family in the southwestern sector………………...23 FIGURE 1.6 Polychaete species number per family in the southeastern sector………………… 24 FIGURE 1.7 Polychaete species number per family in 0-20 meters depth……………………... 25 FIGURE 1.8 Polychaete species number per family in 20-60 meters depth……………………. 26 FIGURE 1.9 Polychaete species number per family in 60-200 meters depth…………………... 28 FIGURE 1.10 Polychaete species number per family in 200- >3000 meters depth…………….. 29 FIGURE 1.11 Cluster diagram based on the Sørensen similarity matrix of the twenty four polygons…………………………………………………………………………………………. 30 FIGURE 1.12 MDS ordination plot based on the Sørensen similarity matrix of the twenty four polygons…………………………………………………………………………………………. 32 FIGURE 1.13 Relative species richness of polychaetes of different mobility classes in the entire Gulf of Mexico…………………………………………………………………………………... 33 FIGURE 1.14 Relative species richness of polychaetes of different mobility classes within the different depth classes…………………………………………………………………………… 34 FIGURE 1.15 Relative species richness of polychaetes of different feeding guilds in the entire Gulf of Mexico…………………………………………………………………………………... 36 FIGURE 1.16 Relative species richness of polychaetes of different feeding guilds within the different depth classes…………………………………………………………………………… 37 FIGURE 1.17 Relative species richness of polychaetes of different feeding guilds within the different regions of the Gulf of Mexico…………………………………………………………. 39 FIGURE 1.18 Relative species richness of polychaetes with different feeding appendages in the entire Gulf of Mexico…………………………………………………………………………….40 xv FIGURE 1.19 Relative species richness of polychaetes with different feeding appendages within the different depth classes……………………………………………………………………….. 41 FIGURE 1.20 Relative species richness of polychaetes of different distribution classes in the entire Gulf of Mexico…………………………………………………………………………….43 FIGURE 1.21 Relative species richness of polychaetes of different distribution classes within the different depth classes…………………………………………………………………………… 44 FIGURE 1.22 Relative abundance of polychaetes of different distribution classes within different regions of the Gulf of Mexico…………………………………………………………………… 46 FIGURE 2.1 Map of the Gulf of Mexico showing the locations of thee three transects from which samples were analyzed………………………………………………………………….. 151 FIGURE 2.2 Detailed map of the station locations of the central transect and the Mississippi Trough………………………………………………………………………………………….. 152 FIGURE 2.3 Detailed map of the station locations of the eastern transect……………………. 153 FIGURE 2.4 Polychaete abundance of different stations and sampling periods at the central transect…………………………………………………………………………………………. 156 FIGURE 2.5 Polychaete abundance of different stations and sampling periods at the eastern transect…………………………………………………………………………………………. 159 FIGURE 2.6 Polychaete abundance of different stations and sampling periods at the Mississippi Trough………………………………………………………………………………………….. 162 FIGURE 2.7 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the central transect…………………………………………... 163 FIGURE 2.8 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the eastern transect…………………………………………...174 FIGURE 2.9 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the Mississippi Trough……………………………………… 176 FIGURE 3.1 Different types of bifurcate notochaetae in Cirrophorus and Paradoneis species………………………………………………………………………………………….. 196 FIGURE 3.2 Strict consensus tree of the seven most parsimonious cladograms for paraonid genera…………………………………………………………………………………………... 216 FIGURE 3.3 Strict consensus tree of 1337 most parsimonious cladograms of Cirrophorus and Paradoneis species……………………………………………………………………………...218 FIGURE 3.4 Majority rule consensus tree of 1337 most parsimonious cladograms of Cirrophorus and Paradoneis species…………………………………………………………... 220 xvi INTRODUCTION Polychaetous annelids are a predominantly marine group of segmented worms. They are frequent and abundant invertebrates in almost any benthic marine habitat at all latitudes and depths. A record from the Tonga Trench in 10,687 meters (Paterson et al. 2009) is among the deepest records for any organism. The oldest fossils of polychaetes, found in the Sirius Passet Lagerstätte in northern Greenland, date back to the lower Cambrian (Conway Morris & Peel 2008). Thus, polychaetes have survived each of the known major extinction events. During their hundreds of millions of years of existence, they have experienced a tremendous adaptive radiation to a wide variety of ecological niches. Different taxa have developed different reproductive strategies (Wilson 1991), morphologies, and feeding modes (Fauchald & Jumars 1979). Many polychaetes are active burrowers that ingest nutrient-enriched sediments and thus are important for the remineralization of particulate organic matter. They can also be considered ecosystem engineers as their bioturbation of the sediment alters the physical and geochemical qualities (Herringshaw et al. 2010) and species composition of their habitat. Other polychaetes are suspension feeders. They have developed sophisticated filter structures, which they use to catch planktonic organisms or marine snow out of the water column. Most diverse are carnivorous and omnivorous polychaetes. Several phylogenetic lineages have developed jaws or teeth. Compared to the scarce fossil record of the soft bodies of polychaetes, their fossilized jaws, the scolecodonts, are common findings. The oldest scolecodonts are from the upper Cambrian (Dutta et al. 2013). In the Ordovician an extensive diversification of scolecodonts took place (Dutta et al. 2013). Many polychaete species are known to live in symbiotic relationships with other invertebrates (Pettibone 1953). Some of the most alien species are found near hydrothermal vents, hydrocarbon seeps, and whale falls. These polychaetes have experienced 1 such tremendous evolutionary adaptations to their habitats that they were originally described in the phylum Pogonophora. These tubeworms lack a mouth, intestinal tract, or an anus. Their nutrition is maintained by endosymbiotic bacteria. Because of their high abundance, polychaetes are an integral part of the diet of other organisms, such as fish (Macer 1967), larger invertebrates such as gastropods (Taylor 1984) and crabs (Petti et al. 1996), and even shore birds (MacDonald et al. 2013). As such, several polychaete species have gained economic importance in the mariculture industry (Olive 1999), or are being tested as a potential food source for farmed fish (Stabili et al. 2013). According to recent studies, the class Polychaeta is paraphyletic (Zrzavý et al. 2009, Struck et al. 2011). This is because the Clitellata (earthworms and leeches), traditionally considered the sister taxon of Polychaeta, seem to be nested within Polychaeta (Zrzavý et al. 2009, Struck et al. 2011). For traditional and ecological reasons, polychaetes are still a commonly accepted group of annelid worms (Fauchald et al. 2009). About 85 families of polychaetes are recognized (Read 2013). However, the phylogenetic relationships of the families are far from being resolved and cladistic analyses of species and genus relationships are scarce. In the Gulf of Mexico more than 800 species of polychaetes have been found (Fauchald et al. 2009). The Gulf offers a variety of benthic habitats, including soft sediment, hard substrate, coral reefs, banks, estuaries, and hydrocarbon seeps. From a biogeographical perspective, the fauna of the Gulf of Mexico is considered transitional between the temperate and boreal North Atlantic fauna and the tropical Caribbean and South American fauna (Hedgpeth 1953). However, this assumption is based on zoogeographical studies of other invertebrate taxa (Spivey 1981) and has not been confirmed for polychaetes. 2 In the northern Gulf of Mexico oil and gas exploration has introduced several anthropogenic alterations into the ecosystem. The roughly 4,000 oil rigs provide artificial hard substrate. Oil blowouts and drilling muds are polluting the continental shelf and margin. Along with global changes to marine ecosystem, such as global warming and ocean acidification these pollutants may affect the biodiversity and species composition of the benthos in the Gulf of Mexico. In chapter one of my dissertation I assessed the biodiversity and species composition of polychaetes in different geographical regions and depths of the Gulf of Mexico, using a comprehensive species list (Fauchald et al. 2009). I examined how the relative abundance of polychaetes with different motilities, feeding strategies, and feeding appendages change with increasing depth and between different areas. Furthermore, I studied the polychaete fauna of the Gulf of Mexico in a zoogeographical context. In the second chapter of my dissertation I studied the biodiversity of polychaete assemblages on the northern Gulf of Mexico continental slope, an area of increasing oil and gas exploration. The main aspect of my research was the assessment of the natural temporal and spatial dynamics of the polychaete communities. Time series studies of deep-sea communities are rare because of difficult and costly sampling procedures. I had the opportunity to study sampling stations from three transects in the northern Gulf of Mexico that had been sampled during different seasons, years and decades. This study may serve as baseline for future studies involving oil spills or other regional and global changes, and it may help distinguish between natural dynamics and anthropogenic alterations of continental slope polychaete assemblages. In chapter three of my dissertation, I studied the systematic relationships of the genera of Paraonidae, one of the most frequently encountered polychaete families in the Gulf of Mexico. In 3 maximum parsimony analyses I tested the hypotheses that the family is monophyletic, and that the genera Cirrophorus and Paradoneis are monophyletic and taxonomically valid. Understanding evolutionary relationships aids a sound taxonomic classification, which is crucial for studies in biodiversity, ecology, and zoogeography. References Conway Morris, S. & Peel, J.S. (2008) The earliest annelids: Lower Cambrian polychaetes from the Sirius Passet Lagerstätte, Peary Land, North Greenland. Acta Palaeontologica Polonica, 53(1), 137-148. Dutta, S., Hartkopf-Fröder, C., Witte, K., Brocke, R. & Mann, U. (2013) Molecular characterization of fossil palynomorphs by transmission micro-FTIR spectroscopy: Implications for hydrocarbon source evaluation. International Journal of Coal Geology, 115, 13-23. Fauchald, K., Granados-Barba, A. & Solís-Weiss, V. (2009) Polychaeta (Annelida) of the Gulf of Mexico. In: Felder, D.L. & Camp, D.K. (Eds.) Gulf of Mexico origin, waters, and biota: Volume I, Biodiversity. Texas A&M University Press, pp. 751-788. Fauchald, K. & Jumars, P.A. (1979) The diet of worms: a study of polychaete feeding guilds. Oceanography and Marine Biology – An Annual Review, 17, 193-284. Hedgpeth, J.W. (1953) An introduction to the zoogeography of the northwestern Gulf of Mexico with reference to the invertebrate fauna. Publications of the Institute of Marine Science, 3(1), 107-224. 4 Herringshaw, L.G., Sherwood, O.A. & McIlroy, D. (2010) Ecosystem engineering by bioturbating polychaetes in event bed microcosms. Palaios, 25(1), 46-58. MacDonald, E.C., Ginn, M.G., & Hamilton, D.J. (2013) Variability in foraging behavior and implications for diet breadth among semipalmated sandpipers staging in the upper Bay of Fundy. The Condor, 115(3), 135-144. Macer, C.T. (1967) The food web in Red Wharf Bay (North Wales) with particular reference to young plaice (Pleuronectes platessa). Helgoländer wissenschaftliche Meeresuntersuchungen, 15(1-4), 560-573. Olive, P.J.W. (1999) Polychaete aquaculture and polychaete science: a mutual synergism. Hydrobiologia, 402, 175-183. Paterson, G.L.J., Glover, A.G., Barrio Froján, C.R.S., Whitaker, A., Budaeva, N., Chimonides, J. & Doner, S. (2009) A census of abyssal polychaetes. Deep-Sea Research II, 56(19-20), 1739-1746. Petti, M.A.V., Nonato, E.F. & Paiva, P.C. (1996) Trophic relationships between polychaetes and brachyuran crabs on the southeastern Brazilian coast. Revista Brasileira de Oceanografia, 44(1), 61-67. Pettibone, M.H. (1953) Some scale-bearing polychaetes of Puget Sound and adjacent waters. University of Washington Press, Seattle, 89 pp. Read, G. (2013). Polychaeta. Accessed through: World Register of Marine Species. Available from http://www.marinespecies.org/aphia.php?p=taxdetails&id=883 (accessed on 6 October 2013). Spivey, H.R. (1981) Origins, distribution, and zoogeographic affinities of the Cirripedia (Crustacea) of the Gulf of Mexico. Journal of Biogeography, 8(2), 153-176. 5 Stabili, L., Sicuro, B., Daprà, F., Gai, F., Abete, C., Dibenedetto, A., Pastore, C., Schirosi, R. & Giangrande, A. (2013) The biochemistry of Sabella spallanzani (Annelida: Polychaeta): a potential resource for the fish feed industry. Journal of the World Aquaculture Society, 44(3), 384-395. Struck, T.H., Paul, C., Hill, N., Hartmann, S., Hösel, C., Kube, M., Lieb, B., Meyer, A., Tiedemann, R., Purschke, G. & Bleidorn, C. (2011) Phylogenomic analyses unravel annelid evolution. Nature, 471(7336), 95-98. Taylor, J.D. (1984) A partial food web involving predatory gastropods on a Pacific fringing reef. Journal of Experimental Marine Biology and Ecology, 74(3), 273-290. Wilson, W.H. (1991) Sexual reproductive modes in polychaetes: classification and diversity. Bulletin of Marine Science, 48(2), 500-516. Zrzavý, J., Říha1, P., Piálek, L. & Janouškovec1, J. (2009) Phylogeny of Annelida (Lophotrochozoa): total-evidence analysis of morphology and six genes. BMC Evolutionary Biology, 9, 189 (14 pp). 6 CHAPTER I Diversity, Distribution, and Zoogeography of Benthic Polychaetes in the Gulf of Mexico Abstract The polychaete diversity of the Gulf of Mexico was examined using a comprehensive species database. The Gulf of Mexico was divided into four geographic regions and six depth classes; β-diversity between the 24 polygons was calculated with the Sørensen similarity index and analyzed in a cluster analysis and in an ordination based on non-metric multidimensional scaling. Both analyses revealed a strong influence of depth on the polychaete assemblages. The polychaete fauna in the southeastern sector was the most distinctive among the four sectors. Each species was assigned to a class in the categories “mobility”, “feeding strategy”, and “feeding appendage” and the compositions of the categories throughout different depths were examined. The categories introduced by Fauchald & Jumars (1979) were amended and the suggested changes discussed. Each polychaete species was assigned a biogeographical class based on their worldwide distributions. Ten percent of the polychaete species were endemic to the Gulf of Mexico. More than 40% of the species were exclusively found in the Atlantic Ocean and the Gulf of Mexico, about one third of the polychaetes had a wide distribution, and 15% of all species were restricted to both coasts of the American continent. Below 200 m more than 30% of the species were endemic to the Gulf of Mexico. Key words: β-diversity, cluster analysis, comprehensive species list, database, endemism, feeding guilds, MDS, species turnover 7 Introduction Polychaetes are segmented annelid worms, mainly found in the marine realm. The oldest known fossils of polychaetes are from the lower Cambrian (Conway Morris & Peel 2008). Thus, polychaetes have endured all of the known major extinction events and have undergone an extensive radiation into about 85 extant families with a wide variety of morphological and ecological adaptations. The most current estimation on the global number of extant polychaete species is 12,632 for described species that are considered taxonomically valid (Appeltans et al. 2012a). Another 6,320 species were estimated yet to be discovered (Appeltans et al. 2012a). The traditional delineation of the annelids into Polychaeta and Clitellata has been challenged by studies based on molecular data (Struck et al. 2011) and molecular and morphological data combined (Zrzavý et al. 2009). Both studies concluded that the class Polychaeta is paraphyletic. Few studies of polychaete diversity, distribution, and community structure have been conducted on the scale of an entire ocean. Most of the related research has been focused on samples of a single survey from smaller areas of interest (e.g., Glover et al. 2001, Fiege et al. 2010). A major obstacle for large scale examinations is the scarcity of comprehensive species lists that cover the entire area studied. Researchers, who have examined large scale diversity and distribution patterns, usually based their analyses on a subset of polychaetes (e.g., Glasby & Alvarez 1999, Wehe 2006, 2007). Large-scale meta-analyses on polychaete diversity were conducted in French waters (Dauvin et al. 2006) and worldwide abyssal and hadal depths (Paterson et al. 2009). The scarcity of comprehensive species lists has been alleviated by the recent development of online databases on marine biodiversity, such as the World Register of Marine Species (Appeltans et al. 2012b) and the Ocean Biogeographic Information System 8 (OBIS 2013). However, these databases are still in their infancies and the distribution data is still incomplete for most polychaete species. The first attempt to list each species recorded from the Gulf of Mexico was accomplished for the compilation of “Bulletin 89” (Galtsoff 1954). The polychaete species list included only 59 species, even though the author mentioned that this number would easily triple when the records of her personal collection were added (Hartman 1954). In an extensive taxonomic study of samples collected during surveys related to the oil and gas exploration in the northern Gulf of Mexico 593 species in 288 genera and 59 families were recorded (Uebelacker & Johnson 1984). In the present study I examined the distribution and diversity of polychaetes from the Gulf of Mexico and their biogeographical affinities based on the data from the Biodiversity of the Gulf of Mexico Database (Moretzsohn et al. 2011). This comprehensive species list, compiled by Fauchald et al. (2009), included records from scientific collections in museums and other research facilities, private collections, scientific literature, and observations (Moretzsohn et al. 2011). The Gulf of Mexico was divided into four regional sectors and six bathymetric classes. Species richness and distribution of species among the different families were investigated within each region and depth. I also compared the faunal similarities among the 24 polygons (six polygons in each of the four sectors) by examining the species turnover rates, also known as β-diversity. My primary goals were to find the hotspots of polychaete diversity and to identify areas that need additional research efforts. Each polychaete species was then assigned to a functional group in the categories mobility, feeding strategy, and feeding appendage in order to examine their relative contributions to the overall polychaete biodiversity. I compared the composition of the different guilds (Fauchald & Jumars 1979) from different regions and depths of the Gulf of Mexico. Each of the species was examined for their global distribution and 9 assigned a biogeographic distribution class. Hence, I was able to examine the biogeographic affinities of the Gulf of Mexico polychaete fauna. Materials & Methods A) Definition of geographic areas and depth classes The border between the Gulf of Mexico and the Atlantic Ocean was defined by Moretzsohn et al. (2011) as the straight line from the vicinity of Key Largo, Florida (25°06'N, 80°26'W) to Punta Hicacos, Cuba (23°12'N, 81°08'W); the border between the Gulf of Mexico and the Caribbean Sea was defined as the straight line from Cabo Catoche, Quintana Roo, Mexico (21°33'N, 87°00'W) to Cabo de San Antonio, Cuba (21°51'N, 84°57'W). For the comparative analysis of the polychaete biodiversity of different geographic and bathymetric areas, the Gulf of Mexico was divided into four large sectors (Northwest, Northeast, Southwest, and Southeast), each of which was subdivided into six depth classes by bathymetric isopleths yielding 24 polygons overall (Fig. 1.1). I followed Moretzsohn et al. (2011) in the division into sectors, with the exception that adjacent sectors (e.g., North-northeast and East-northeast) were merged because their polychaete presence data were identical. For the sake of brevity and consistency, I followed the nomenclature of Moretzsohn et al. (2011) and refer to the northeastern sector (the merged sectors A and B from Moretzsohn et al. (2011)) as region A, the southeastern sector (the merger of the original sectors C and D) as region C, the southwestern sector (the merger of the original sectors E and F) as region E, and the northwestern sector (the merger of the original sectors G and H) as region G (Fig. 1.1). Depth classes were defined by the bathymetric boundaries at 20 m, 60 m, 200 m, 1000 m, and 3000 m. Depth class one refers to water depths of 0-20 m, depth class 10 11 FIGURE 1.1 Map of the Gulf of Mexico with color coded bathymetry and sector boundaries. A = northeastern sector; C = southeastern sector; E = southwestern sector; G = northwestern sector. two to 20-60 m, depth class three to 60-200 m, depth class four to 200-1000 m, depth class five to 1000-3000 m, and depth class six to depths below 3000 m. Each of the 24 polygons is denoted by a combination of a letter for its geographic region and a number for its depth class, e.g., G3 is the polygon in the northwestern sector with a depth range of 60-200 m. B) Analyses The analyses of this study were based on a comprehensive polychaete species list of the Gulf of Mexico (Fauchald et al. 2009), which was obtained from the Biodiversity of the Gulf of Mexico database (BioGoMx) (Moretzsohn et al. 2011). The list contained each polychaete species recorded by the time of the publication of the recent new edition of “Bulletin 89” (Felder & Camp 2009). The data for the analyses were in a presence and absence format. A quantitative approach was infeasible because of the wide variety of sampling methods used during the different surveys on which the species list is based. Pelagic polychaete species were excluded from the analyses. Species names were updated to the current taxonomy, according to the “World Register of Marine Species” (WoRMS) database (Appeltans et al. 2012b). A taxonomically updated species list with incidence data of each sector and depth class, feeding strategy, feeding appendage, and zoogeographical distribution is provided (Table 1.1). Taxonomic updates are listed under comments in Table 1.1 and refer to the species list by Fauchald et al. (2009). In cases of objective synonymies, i.e. where species were transferred to another genus, the old name was included as “Listed as [objective synonym]”. Subjective synonymies, i.e. where two species are considered synonymous, are referenced as “Senior synonym of [junior synonym]”. In cases where senior and junior synonyms were both listed in Fauchald et al. (2009), junior synonyms were erased 12 from the list, and indicated in the comments of the senior synonym in Table 1.1 as “Includes records of junior synonym [synonymized species name]”. Subgenera are omitted in Table 1.1. Several species are listed with the addition of “cf.” for uncertain species identification; others were listed as “species indet.” indicating an unidentified species. The unidentified species all belonged to distinct genera, and all species with uncertain or unknown species affiliation were treated as distinct “operational taxonomic unit” and included in the analyses, except in the analysis of the biogeographical affinities of the Gulf polychaete fauna (see below). Several species in the list of Fauchald et al. (2009) are missing data on their depth distribution within the Gulf of Mexico. Depth records of some of these species were added from original descriptions and revisions. Species for which the depth distribution in the Gulf of Mexico was not found in the primary literature were excluded from analyses involving comparisons of polygons and depth classes, but they were included in analyses involving the entire Gulf and the four sectors. I used the Sørensen-Index (Sørensen 1948), mathematically modified after Clarke & Gorley (2006), for comparing the polychaete diversity among the 24 polygons. This index measures the similarity between two samples with the formula βs = 100*[2a/(2a+b+c)], where a is the number of species occurring in both polygons, b is the number of species occurring only in the first of the polygons compared, and c the number of species occurring only in the second of the polygons compared. Comparing all 24 polygons amongst each other resulted in a matrix of 276 βs values. Based on this matrix, a cluster analysis using the group average linking algorithm was performed. Ordination plots based on non-metric multidimensional scaling (MDS) were created. The aforementioned analyses were conducted with Primer 6 (Clarke & Gorley 2006). 13 C) Functional groups Each species was classified in the categories mobility, feeding strategy, and feeding appendage. Whereas the morphology of the feeding apparatus is usually known from individual species and documented in species descriptions, only a few polychaete species from the Gulf of Mexico have been studied in terms of feeding strategies and diet. Hence, I had to infer the assignment to categories based on the morphology of the feeding appendages and the data on the feeding ecology available for closely related species, genera, and, in some cases, even families. In essence, I followed the classification scheme of Fauchald & Jumars (1979). However, I added several categories of feeding modes and feeding appendages, and I also changed the classification of several species. Three categories of feeding strategies are newly introduced: “omnivores”, “deposit feeders with facultative suspension feeding”, and “hosts of symbionts”. The latter category is restricted to the family Siboglinidae, which are exclusively found in the vicinity of hydrocarbon seeps (and hydrothermal vents in other oceans) and obtain their nutrition by the chemosynthetic activity of their bacterial endosymbionts. Polychaetes that are capable of both suspension and deposit feeding belong chiefly to Spionidae and several related families, as well as the Fabriciidae. While spionids and related families are usually considered deposit feeders, several species have been observed using their palps for suspension feeding under certain hydrographic conditions (Dauer et al. 1981). Most species of Spionidae and related families have the capability to switch between feeding modes. Spionids that construct burrows in shells and other calcareous structures are herein considered strict suspension feeders. Species of the family Fabriciidae show different degrees of simplification of the sophisticated filter structures of their relatives, the strictly suspension-feeding Sabellidae. The category “Omnivores” was introduced for opportunistic feeders. I disagree with Fauchald & Jumars 14 (1979), who proposed that up to five different feeding guilds occur within a single family, and that individual species use only one of the various feeding strategies (Fauchald & Jumars 1979, p. 219). Instead, observations of different feeding modes and inconsistent results of gut content analyses within a single family, genus, and even species, is the result of their opportunistic feeding habits. Therefore, most species of families for which different feeding habits have been recorded, such as Dorvilleidae, Eunicidae, Glyceridae, Lumbrineridae, Nephtyidae, Nereididae, and Onuphidae are considered to be omnivorous. I did not include the category “herbivores” even though several species have been cultured on a strict vegetarian diet. Some of these “herbivorous species” are most likely omnivores that rely on a vegetarian diet only in the absence of prey and carrion. Other polychaetes, most notably the Paraonidae, which feed mainly on foraminiferans, diatoms, and dinoflagellates, are considered deposit feeders because their gut content consists largely of sediment and frustules (Gaston et al. 1992). Some of the data in Fauchald & Jumars (1979) was updated according to several authors in a review edited by Beesley et al. (2000). Mobility included the categories “mobile”, “discretely mobile”, and “sessile”. “Discretely mobile” was assigned to species that are principally mobile, but live a sedentary lifestyle for extended periods. Categories of feeding strategies were defined as “surface deposit feeders”, “subsurface deposit feeders”, “deposit feeders with facultative suspension feeding”, “suspension feeders”, “carnivores”, “omnivores”, and “hosts of symbionts”. Categories of feeding devices were “armed pharynx”, “unarmed pharynx”, “palps”, “unarmed pharynx plus palps”, “radula like pharynx”, “tentacles”, “filtering device”, “lips”, “lips plus tentacles”, and “pumping structure”. The relative contribution of each of the classes within the three categories was calculated for the 15 entire Gulf and the different depth classes. Depth classes 4, 5, and 6, as defined above, were lumped together for the analyses because of their low species numbers. D) Biogeographical categories A worldwide geographical distribution range was assigned to each species, based on data in the WoRMS database and extensive literature research. The eight biogeographical categories used in this study are: “endemic”, “NW Atlantic”, “SW Atlantic”, “W Atlantic”, “Pan-Atlantic”, “Pan-American”, “Holarctic”, and “widely distributed”. Endemic species are those that are exclusively recorded from the Gulf of Mexico. The NW Atlantic species have been recorded from the West Atlantic coast north of the Gulf of Mexico, i.e., the North American Atlantic coast, including Bermuda. The SW Atlantic species have been recorded from the West Atlantic south of the Gulf of Mexico, i.e., the Caribbean and/or the South American Atlantic coast (hence SW Atlantic does not necessarily imply southern latitudes). W Atlantic species were recorded from the West Atlantic, both north and south of the Gulf of Mexico, as defined above. The Pan-Atlantic species were recorded on both sides of the Atlantic, whereby the Mediterranean Sea and the North Sea were considered part of the East Atlantic. Pan-American species were recorded exclusively from America, both the Pacific and Atlantic coastlines, including Galapagos. Holarctic species were recorded in the North Atlantic, the North Pacific and the Arctic. Widely distributed species were either found in many different parts of the world’s oceans (cosmopolitan species), or they had a disjunct distribution, e.g., they were found in remote locations, such as Antarctica or the Indian Ocean. Taxa with unknown or uncertain specific affiliation, i.e., those listed as “species indet.” and “cf.”, respectively, were excluded from this analysis. The relative contribution of each biogeographical class was calculated for the 16 different sectors and depth classes. Bathymetry classes 4, 5, and 6, were lumped together for this analysis because of their low species numbers. E) Abbreviations Abbreviations used in Table 1.1 are: NW: northwestern sector; NE: northeastern sector; SW: southwestern sector; SE: southeastern sector; D1-6: Depth classes 1-6 as defined above; M: Mobility, including the categories M = mobile, D = discretely mobile, S = sessile; F: Feeding strategy, including SS = subsurface deposit feeder, SD = surface deposit feeder, DS = deposit feeder with facultative suspension feeding, SU = suspension feeder, CV = carnivore, OV = omnivore, SY = host of symbionts; A: Feeding appendage, including UP = unarmed pharynx, PA = palps, PP = unarmed pharynx and palps, AP = armed pharynx, R = radula like pharynx, TE = tentacles, FI = filtering structure, LI = lips, LT = lips and tentacles, PU = pumping device, NP = not present; D: Distribution class, including EN = endemic, NW = West Atlantic, north of the Gulf of Mexico, SW = West Atlantic, south of the Gulf of Mexico, WA = West Atlantic, north and south of the Gulf of Mexico, AT = Pan-Atlantic, AM = Pan-American, HA = holarctic, WD = widely distributed. Results A) Species richness analysis Based on the taxonomically updated comprehensive polychaete species list by Fauchald et al. (2009), 829 species and six subspecies of benthic polychaetes, belonging to 386 genera and 60 families, have been recorded from the Gulf of Mexico (Table 1.1). Forty-four of these species 17 were not identified with certainty (“cf.”), 39 of them were not identified to species but genus level (“species indet.”). Compared to the polychaete list of the first “Bulletin 89” (Galtsoff 1954) with only 59 species, the number has increased by more than fourteen times. The most diverse family in the Gulf of Mexico by far is Syllidae with 90 species, followed by Spionidae with 48 species, Eunicidae and Nereididae with 42 species each, Serpulidae with 38 species, Sabellidae with 37 species, Lumbrineridae with 35 species, Paraonidae with 34 species, and Terebellidae with 30 species. Eleven families were represented by only one species (Fig. 1.2). The most species rich of the four geographical sectors was the northeastern with 602 species, followed by the southwestern with 465 species, the northwestern with 261 species, and the southeastern with 154 species. In the diverse northeastern sector all of the 60 benthic polychaete families occurring in the Gulf were recorded, except for the Siboglinidae. Syllidae were most diverse with 64 recorded species, followed by Spionidae with 35 species, Paraonidae with 29 species and Terebellidae with 27 species (Fig. 1.3). In the northwestern sector 15 of the 60 polychaete families were absent, and 10 families were represented by only a single species. Scalibregmatidae, represented by nine species in the Gulf, was the most prominent family missing from the northwestern sector. Families with conspicuously low species numbers in the northwestern sector were Cirratulidae with two species, compared to 22 species in the entire Gulf, and Serpulidae with three species compared to 38 species in the entire Gulf. The Spionidae were most speciose with 24 species, followed by Syllidae with 20 species, Nereididae with 17 species, and Onuphidae with 12 species (Fig. 1.4). 18 FIGURE 1.2 Polychaete species number per family in the entire Gulf of Mexico. 19 FIGURE 1.3 Polychaete species number per family in the northeastern sector. 20 FIGURE 1.4 Polychaete species number per family in the northwestern sector. 21 In the southwestern sector 47 out of the 60 polychaete families were present. Those that were absent had a generally low species richness of one to four species within the entire Gulf of Mexico. The most diverse families were Syllidae with 46 species, followed by Spionidae with 36 species, Nereididae with 31 species, and Lumbrineridae with 27 species (Fig. 1.5). In the least diverse southeastern sector 21 families were absent, the Ampharetidae with 13 species reported from the Gulf being the most prominent one. Most other families were underrepresented. The most species rich family in the southeastern sector was Eunicidae with 19 species, followed by Syllidae with 17 species, Sabellidae with 13 species, and Spionidae with nine species (Fig. 1.6). Species richness of the different depth classes was as follows: 212 species have been recorded in 0-20 m, 529 species in 20-60 m, 253 species in 60-200 m, 27 species in 200-1000 m, six species in 1000-3000 m, and six species below 3000 m. In the shallowest depth class 41 families were present. Spionidae had the highest species count with 17, Nereididae and Syllidae were represented by 16 species each, and Eunicidae by 14 species. Particularly well represented families in the shallowest waters were Pilargidae with 13 of 22 species present in the entire Gulf, Capitellidae with 11 of 19 species, Chrysopetalidae with seven of 10 species, Magelonidae with six of nine species, Fabriciidae with four of six species, Oweniidae with two of three species, and Arenicolidae with its only species being restricted to the shallowest depth class. The most diverse family absent from the shallowest depths was Sphaerodoridae, represented by seven species in the Gulf (Fig. 1.7). In the second depth class 54 families were present. Syllidae were most diverse with 61 species, followed by Spionidae with 33 species, Paraonidae with 27 species, and Terebellidae with 26 species (Fig. 1.8). 22 FIGURE 1.5 Polychaete species number per family in the southwestern sector. 23 FIGURE 1.6 Polychaete species number per family in the southeastern sector. 24 FIGURE 1.7 Polychaete species number per family in 0-20 meters depth. 25 FIGURE 1.8 Polychaete species number per family in 20-60 meters depth. 26 In the third depth class 48 polychaete families were present. The most species rich families were Syllidae with 29 species, Lumbrineridae with 15 species, Spionidae with 14 species, and Eunicidae with 12 species. One of the most prominent polychaete families, the Polynoidae, has not been recorded from depth class three, and the Cirratulidae were represented by only a single species (Fig. 1.9). In the fourth depth class 10 families were recorded, the most species rich ones being Acoetidae, Eunicidae, Polynoidae, and Siboglinidae with four species each (Fig. 1.10A). In the fifth depth class five families were recorded, with Onuphidae being represented by two species, and Eunicidae, Polynoidae, Siboglinidae, and Sigalionidae by one species each (Fig. 1.10B). In the sixth depth class five families have been found. Nautiliniellidae were represented by two species, Orbiniidae, Polynoidae, Siboglinidae, and Sigalionidae by one species each (Fig. 1.10C). Forty eight of the 60 families have not been recorded below 200 m, including prominent families such as Spionidae, Nereididae, Serpulidae, and Sabellidae. B) Comparative analysis of the Gulf of Mexico polychaete biodiversity The comparison of the polychaete fauna among the 24 polygons resulted in two distinct clusters. One cluster contained all continental shelf polygons of depth classes one to three, the other one the polygons of the continental slope and the abyssal plain, i.e., depth classes four to six. The similarity between these two clusters is very low (Fig. 1.11). Among the continental shelf polygons the ones of the southeastern sector formed one cluster. In contrast, the polygons of the three other sectors formed two clusters, according to their bathymetry, i.e., one that included all polygons of depth class one and another one that included the polygons of depth class two and three. Similarly, in the deep-sea the southeastern sector was most distinct and formed one cluster. 27 FIGURE 1.9 Polychaete species number per family in 60-200 meters depth. 28 FIGURE 1.10 Polychaete species number per family. A: in 200-1000 meters depth; B: in 1000-3000 meters depth; C: in >3000 meters depth. 29 30 FIGURE 1.11 Cluster diagram based on the Sørensen similarity matrix of the twenty four polygons. A = northeastern sector; C = southeastern sector; E = southwestern sector; G = northwestern sector; numbers 1-6 represent the six depth classes. The polygons of the northwestern, northeastern, and southwestern sectors clustered together. An exception was the deepest polygon of the southwestern sector, which clustered with the southeastern deep-sea polygons. The northwestern, northeastern, and southwestern deep-sea polygons clustered according to their bathymetry (Fig. 1.11). In the ordination (Fig. 1.12) the same clusters were represented in a two-dimensional plot. Polygons are horizontally arranged according to depth and vertically according to their geographic regions. The two main clusters are very distinct with shallow stations to the right and deep stations to the left. The distinctness of the southeastern cluster compared to the three other sectors is conspicuous as they are consistently on top of the plot. The vertical order of the polygons from top to bottom is consistently southeast (C), southwest (E), northwest (G), northeast (A), except for the shallowest depth class where the northeastern and the northwestern sector have switched positions. Other exceptions were polygon C4 that was relatively dissimilar from the other southeastern deep-sea polygons C5 and C6 (which were identical), and the southwestern polygon E6 that clustered with the C5 and C6. C) Distribution of functional groups Four hundred and eighty two species, or more than half (57%) of the polychaetes in the Gulf of Mexico were mobile. One hundred and ninety seven species, or nearly one quarter (24%) of the Gulf polychaetes, were discretely mobile. One hundred and fifty six, nearly one out of five species (19%) were sessile (Fig. 1.13). The relative contribution of discretely mobile species decreased consistently with depth, that of sessile polychaete increased consistently, albeit slightly (Fig. 1.14). 31 32 FIGURE 1.12 MDS ordination plot based on the Sørensen similarity matrix of the twenty four polygons. A = northeastern sector; C = southeastern sector; E = southwestern sector; G = northwestern sector; numbers 1-6 represent the six depth classes. C5 and C6 are identical. 33 FIGURE 1.13 Relative species richness of polychaetes of different mobility classes in the entire Gulf of Mexico. 34 FIGURE 1.14 Relative species richness of polychaetes of different mobility classes within the different depth classes. D = Depth classes 4-6 lumped together. Among the different feeding guilds the omnivores were most diverse with 252 species, which means that almost one third (31%) of the Gulf of Mexico polychaete species were opportunistic feeders. Two hundred and three, nearly one quarter (24%) of all species were carnivores. Subsurface deposit feeder contributed 123 species, or 15% of the of the polychaete fauna. The surface deposit feeding guild was represented by 108 species, or 13% of the total. Ninety two species (11%) were suspension feeders. Fifty four species, which equals about six percent, belonged to deposit feeders with facultative suspension feeding. Only three species wereknown to rely on endosymbionts (Fig. 1.15). The percentages of the different feeding strategies in depth classes one to three were more or less concordant with the ones described above for the entire Gulf. In the lumped depth classes four to six, the hosts of symbionts, which were entirely absent in the shallow water, appeared. The share of carnivores increased more than twofold in the deep-sea. All other categories of feeding strategies decreased in their relative contribution with depth (Fig. 1.16). The comparison of the relative contribution of the different feeding guilds to the regional faunas, i.e., the four different sectors, revealed that the northeastern and the southeastern sectors were often complementary. This corroborates the observations from the MDS plot where the polygons of the northeastern and the southeastern sector were in opposite positions. Surface deposit and subsurface deposit feeders had their highest relative species richness in the northeastern sector (17% and 14%, respectively) and their lowest relative species richness in the southeastern sector (13% and 5%, respectively). In contrast, omnivores and suspension feeders had their highest share in the southeastern sector (36% and 15%, respectively), and their lowest share in the northeastern sector (28% and 8%, respectively). Only the carnivores feeding guild was nearly equally well distributed among both eastern sectors. The two western sectors usually 35 36 FIGURE 1.15 Relative species richness of polychaetes of different feeding guilds in the entire Gulf of Mexico. 37 FIGURE 1.16 Relative species richness of polychaetes of different feeding guilds within the different depth classes. D = Depth classes 4-6 lumped together. had intermediate positions in the relative species number of feeding strategies. Exceptions were the low relative contribution of carnivores in the southwestern sector (19%, compared to 23-25% in the other sectors) and the slightly higher contribution of deposit feeders with facultative suspension feeding in the northwestern sector (10%, compared to 7-9% in the other sectors) (Fig. 1.17). The armed pharynx was the most frequently encountered feeding appendage, found in 384 species, or 46% of the total number. One hundred and ninety species had an unarmed pharynx, making them the second largest group with 23% of all Gulf polychaete species. Species with palps and an unarmed pharynx and species with a filter device both contributed 10%, with 87 and 86 species, respectively. Fifty five species, or 7% of the total, had multiple tentacles. Two percent fell into each of the classes “palps” and “radula-like pharynx”, with 14 and 13 species, respectively. Three siboglinid species do not have any feeding appendages, two oweniids use their lips or lips plus tentacles, respectively, and Chaetopterus variopedatus uses a peculiar pumping mechanism and a mucus trap (Fig. 1.18). The relative frequency of the different feeding appendages did not change much between depth classes one, two, and three. In the lumped depth class four to six, the relative contribution of polychaetes with armed pharynx increased conspicuously, which is concordant with the observation of the relative increase of carnivores in the deep-sea. The group “others” increased because of the presence of the siboglinids at the hydrocarbon seeps in the deep sea. The relative abundance of polychaetes with unarmed pharynx decreased consistently with depth (Fig. 1.19). D) Biogeographic affinities of the Gulf of Mexico polychaete fauna For the analysis of the biogeographical affinities of the Gulf of Mexico, 83 taxa with unknown or uncertain species affiliation were excluded, leaving a pool of 752 species. Seventy two of the 38 39 FIGURE 1.17 Relative species richness of polychaetes of different feeding guilds within the different regions of the Gulf of Mexico. NE = northeastern sector; SE = southeastern sector; SW = southwestern sector; NW = northwestern sector. 40 FIGURE 1.18 Relative species richness of polychaetes with different feeding appendages in the entire Gulf of Mexico. 41 FIGURE 1.19 Relative species richness of polychaetes with different feeding appendages within the different depth classes. D = Depth classes 4-6 lumped together. species, or approximately 10%, are currently considered endemic. Three hundred and ten species, or 41%, were restricted to the Atlantic Ocean and its ephemeral seas. Seventy-one of them were widely distributed within the Atlantic and occurred on the coasts of the Americas and of Western Africa and/or Europe. The remaining 239 species were restricted to the Western Atlantic. Eighty-five of them extended their distributional range to the Atlantic north of the Gulf of Mexico, 75 species to the south of the Gulf, and 79 species into both directions. One hundred and fourteen species occurred on both sides of the American continent. The Pan-American polychaetes comprised 15% of the species pool. With a contribution of 12 species (2%), holarctic polychaetes were rare. About one third of the Gulf of Mexico polychaetes were widely distributed, which either means they occur in many different locations around the world, or they have been recorded in remote places, such as Antarctica or the Indian Ocean, in addition to the Gulf of Mexico. Two hundred and forty three of the 752 species were widely distributed (Fig. 1.20). When comparing the relative contribution of each distribution class among the different depth classes, it was most striking that the relative frequency of endemic species dramatically increased from less than 10% on the continental shelf to more than 30% below the shelf break, i.e., the lumped depth class four to six. In depth class six five out of six recorded species were endemic. In contrast, the contribution of widely distributed species in the deep sea decreased by almost half. Additionally, the relative contributions of the Pan-Atlantic species and the species of the Caribbean and South American Atlantic coast increased with depth. Conversely, the relative frequency of northwest Atlantic and Pan-American species decreased with depth (Fig. 1.21). The rate of endemics was higher in the northern sectors (almost 10%), than in the southern sectors (slightly above 5%). The fauna of all four sectors had considerable species overlap with the 42 43 FIGURE 1.20 Relative species richness of polychaetes of different distribution classes in the entire Gulf of Mexico. 44 FIGURE 1.21 Relative species richness of polychaetes of different distribution classes within the different depth classes. D = Depth classes 4-6 lumped together. fauna of the Western Atlantic. The southeastern sector had a high contribution of polychaetes occurring in the West Atlantic, north and south of the Gulf of Mexico. Both northern sectors contained more species from the Northwest Atlantic, than from the Caribbean and Southwest Atlantic. Particularly, the northeastern sector was characterized by a relatively strong representation of northwestern Atlantic polychaetes and a relatively weak representation of southwestern Atlantic polychaetes. Both southern sectors had a higher relative share of species from the Caribbean and South American coasts, and a lower share of boreal and temperate species from the North American Atlantic coast. The southwestern sector had the highest contribution of southern species, and the lowest contribution of northern species. The Pan-American group contributed relatively more to the species richness in the two western sectors. Widely distributed polychaetes were frequent throughout, ranging from 31% in the southeastern sector to 38% in the northwestern sector (Fig. 1.22). Discussion A) Species richness analysis Polychaete species richness in the Gulf of Mexico (829 species, six subspecies) is comparable to the Mediterranean Sea with 876 species recorded (Castelli et al. 2008) and the seas surrounding the Arabian Peninsula with 788 species, 16 subspecies, and three species groups (Fiege & Wehe 2002). The high number of species in the northeastern sector and the low number in the southeastern sector may, in part, be caused by the relatively large and small continental shelf areas, respectively. The southeastern sector, bordering the Atlantic Ocean and the Caribbean Sea, might be expected to contain the most heterogeneous assemblage of boreal and temperate fauna 45 46 FIGURE 1.22 Relative abundance of polychaetes of different distribution classes within different regions of the Gulf of Mexico. NE = northeastern sector; SE = southeastern sector; SW = southwestern sector; NW = northwestern sector. from the North Atlantic and tropical species from the Caribbean and equatorial Atlantic. The differences in the number of species among the different regions may be confounded by the unequal sizes of the four sectors with the northeastern and southwestern sector being larger than the southeastern and the northwestern sectors. Unequal sampling efforts may introduce another bias. This concerns mostly the southeastern sector, where Cuba is located. While the three other sectors have been studied relatively extensively, faunistic and ecological surveys in the southeastern Gulf are relatively scarce. This may be the main reason why the number of recorded polychaete species is low. The deep-sea below 200 m is severely undersampled and the polychaete fauna from the continental slope and the abyssal plain is elusive. Furthermore, the different polychaete families have not received the same taxonomic attention. Examples of more extensively studied families include Syllidae, which were covered in a series of papers (San Martín 1990, 1991a, 1991b, 1992), and Eunicidae and Onuphidae, which underwent revisions (Fauchald 1982, 1992). Whereas the known number of species within these families may approximate the true species richness in the Gulf, the diversity of taxonomically more neglected families may be vastly underestimated. Another potential pitfall is the dependency of the results on the taxonomic accuracy of the data. This is because polychaete species level identifications are difficult and in many ecological studies this task is performed by non-specialists. Nevertheless, the list provided by Fauchald et al. (2009) is likely one of the most comprehensive, accurate, and up-to-date polychaete species lists available for any of the world’s oceans. B) Comparative analysis of the Gulf of Mexico polychaete biodiversity The shelf break was the approximate boundary of a sharp bathymetric change of the polychaete fauna. More deep-sea sampling is necessary to corroborate this result since only 30 species from 47 below 200 m were recorded. Noteworthy is the position of the southeastern polygons in the cluster analysis and the ordination. Both shallow (C1-3) and deep polygons (C4-6) formed clusters distinct from the other areas within the two main clusters. The southeastern sector’s connection to the North Atlantic and the Caribbean Sea may have an important role for this phenomenon by contributing boreal and temperate polychaetes from the North American with their southernmost extension and tropical polychaetes from the Caribbean and South America with their northernmost extension in the southeastern Gulf of Mexico. This hypothesis was, however, not supported by the data because the biogeographic classes “NW Atlantic” and “SW Atlantic” were not more frequent in the southeastern sector, than in the other sectors. The polygons of the three other sectors clustered according to their bathymetric depth class, with the exception of the deepest southwestern polygon, which clustered with the otherwise distinct southeastern polygons. Polygons of the shallowest depth class of the northeastern, northwestern, and southwestern sectors were more similar to each other, than to polygons of depth classes two and three of the same sectors. In other words, the polychaete fauna of the Texas coast in 0-20 m is more similar to the polychaete fauna of the same depth in Florida and Veracruz, than to the Texas polychaete fauna in 20-60 m. This may be caused by a number of species that are specifically adapted and restricted to the harsh environment of the intertidal zone. The different ecological conditions in intertidal and subtidal habitats have the potential to cause speciation in polychaetes (Kruse et al. 2004). C) Distribution of functional groups Mobile species accounted for more than half of the polychaete fauna. The relative abundance of the three categories did not change much among the different depth classes. This was somewhat 48 surprising as the capability to leave nutrient-deprived habitats and prospect for new food sources seems crucial for life in the deep-sea, and a sessile lifestyle seems therefore unfavorable. However, even some of the sessile polychaetes have a limited capability to leave their burrows if they are forced to, e.g., ampharetids (Guillou & Hily 1983), and sabellids (Mareano 2013). More than half of the polychaete species in the Gulf of Mexico were either carnivorous or omnivorous. In contrast, deposit feeders were routinely the most abundant polychaetes in quantitative samples from the northern Gulf of Mexico (personal observations), most notably Spionidae (mostly deposit feeders with facultative suspension feeding), Paraonidae, Maldanidae (subsurface deposit feeders), and Cirratulidae (surface deposit feeders). Schüller et al. (2009) in their study on community structure of the polychaete fauna in the Southern Ocean also found that carnivorous and omnivorous polychaetes (therein lumped as “vagile habit group”) contributed more to the relative species richness than to the relative abundance, and deposit feeders (therein lumped as “burrowing habit group”) contributed more to the relative abundance than to the relative species richness. This suggests that carnivores and omnivores have undergone a higher diversification than the deposit feeders. Many carnivorous and omnivorous polychaetes may be highly specialized for certain prey items or symbiotic relationships, therefore creating many niches with narrowly defined niche space. The two polychaete families considered most speciose worldwide, Syllidae and Polynoidae, are known for their many symbiotic relationships with other invertebrates, including sponges (Pawlik 1983), corals (Glasby & Watson 2001), bivalves (Pettibone 1984), limpets (Pettibone 1953), crustaceans (Martin et al. 2008), and sea stars (Pettibone 1953). Most symbiotic polychaetes are assumed to be obligate symbionts (Pettibone 1953). Dorvilleidae (largely belonging to omnivores) are found in high diversity at hydrothermal vents (Desbruyères et al. 2006), cold seeps (Baco et al. 2010), and whale falls 49 (Baco & Smith 2003). Conversely, abundant deposit feeders such as capitellid polychaetes are considered to be non-selective in their sediment ingestion (Fauchald & Jumars 1979). They are also well known for their ability to cope with harsh environments, such as polluted and oxygendepleted habitats (e.g., Reish 1957). Being opportunistic, adaptive, and less specialized, many of the deposit feeding polychaetes may occupy a larger niche space and may therefore not have experienced a comparable adaptive radiation as carnivores and omnivores. D) Biogeographic affinities of the Gulf of Mexico polychaete fauna Most polychaete families and genera are cosmopolitan in their distribution, possibly because of the old age of the taxa (Fauchald 1984). Polychaetes have existed at least since the lower Cambrian (Conway Morris & Peel 2008). I found that even on a species level a large proportion (about one out of three species recorded in the Gulf of Mexico) had a wide distribution. A study from the Indo-Pacific found that 40% of the species were cosmopolitan (Knox 1957). Other polychaete faunas with a considerable proportion of widely distributed include the Magellan region (Montiel San Martín et al. 2005), the South Atlantic (Fiege et al. 2010), and the Southern Ocean (Schüller & Ebbe 2007). Many polychaete species have planktotrophic larvae that facilitate their long distance dispersal. The larvae may use the global conveyor belt of ocean currents, including the circumtropical current of the Southern Ocean as a “hub” connecting their populations in the Atlantic and the Indo-Pacific. The importance of anthropogenic dispersal via ship traffic and ship channels such as the Panama Canal may also become increasingly important. The number of widely distributed species may be biased by inaccurate species identifications, i.e., if they were incorrectly identified as species described from remote locations. The correctness can only be resolved by regional taxonomic revisions of the various 50 taxa. However, species with disjunct or wide distributions do exist in the Gulf of Mexico (Imajima et al. 2013). Another problem innate to studies based on species identifications is the existence of cryptic species, i.e., distinct species that are not distinguishable by their morphology. Cryptic speciation among polychaetes is well documented from several species complexes that occur in the Gulf of Mexico, e.g., Capitella capitata (Grassle & Grassle 1976), Streblospio benedicti and S. gynobranchiata (Schulze et al. 2000), and Eurythoe complanata (Barroso et al. 2010). Many of the Gulf species also occur in the Atlantic Ocean. The Gulf contains species from the boreal and temperate North American Atlantic coasts, the tropical Caribbean, and the South American Atlantic coasts. Both biogeographical classes contain similar numbers of species, suggesting that the Gulf of Mexico is a transition zone between temperate and tropical polychaete fauna. This finding is in agreement with the zoogeography of the Gulf of Mexico barnacles (Spivey 1981). Another surprisingly large fraction of species occurs on both coasts of the American continent. Some of the Pan-American species have a continuous record along the American coasts. Others are only recorded in the Gulf of Mexico and other tropical and subtropical regions on the eastern side of the continent, and from tropical and subtropical regions of the Pacific coast. These species may have existed before the Isthmus of Panama closed about 3.1-2.8 MYA (Coates & Obando 1996), and then formed a continuous population. Some of these tropical and subtropical polychaete species may not have developed sufficient genetic or reproductive barriers in the relatively short period since the vicariance. The Pacific and Caribbean populations may therefore still belong to the same biological species (Mayr & Ashlock 1991). The recently introduced connection of the Pacific and the Caribbean Sea through the Panama Canal may help 51 to re-establish genetic connectivity of the populations of shallow water polychaetes or species that have shallow water larvae. However, the freshwater locks of the Panama Canal may prevent migrations (Rubinoff 1968). Other tropical and subtropical Pan-American species may have diverged enough to be considered separate species. If the morphology of the Pacific and Atlantic sibling species has not changed sufficiently yet to warrant them being considered as separate species, cryptic sibling species may have been considered as one species with Pan-American distribution. Therefore, the proportion of Pam-American species may be overestimated. The share of endemic polychaete species was low (10%) in the Gulf of Mexico. Hartman (1951) suggested that about fifteen percent are endemic, based on the then comprehensive list of polychaetes including 154 species. Hedgpeth (1953) suggested the rate of endemism for most other invertebrate taxa to be around 10% in the Gulf of Mexico. Endemism among barnacles is at fourteen percent in the Gulf of Mexico (Spivey 1981). The rate of endemism may rise with the detection of cryptic species. The dramatic increase of endemic species and decrease of widely distributed species at the continental slope and the abyssal plain is in stark contrast to the decapod crustaceans of the Gulf of Mexico (Wicksten & Packard 2005). Most of the deep-sea decapods were considered cosmopolitan and may be, according to the authors, “remnants of ancient seas”. The increase of endemism among polychaetes in the deep-sea may be influenced by the relatively shallow connection with the Atlantic through the Florida Strait and the deeper but narrow trench system in the Yucatan Channel, which may act as a barrier for those species that are stenobathic and have direct development or deep-water larvae. Several of the deep-water species were recorded from hydrocarbon seeps, including all of the highly specialized Siboglinidae and the obligate symbionts of the family Nautiliniellidae. Most species from cold seeps are adapted to this chemosynthetic environment and are not found in any other habitat. 52 Clearly, the finding of a unique deep-sea polychaete fauna has to be considered preliminary because the analysis was based on a small number of species. The continental slopes and abyssal plain require additional sampling effort. E) Outlook and recommendations My research demonstrates how a database can be used to study large scale patterns of biodiversity, community structure, and biogeographical aspects of a large and omnipresent benthic marine group such as polychaetes. The development and curation of freely available databases with comprehensive information on taxonomy, ecology, and distribution of individual species is a highly desirable goal in the endeavor to understand and protect global biodiversity. The results of this study have to be considered preliminary because our knowledge of the biodiversity of the Gulf of Mexico remains fragmentary. Additional sampling is critical to understand the patterns of biodiversity and the distribution of polychaete species in the Gulf of Mexico. Sampling of the southeastern Gulf of Mexico, specifically along and off the coast of Cuba, and the deep-sea beneath 200 m, should be prioritized. Most polychaete families are in need of global and regional revisions. Clear species boundaries have to be established by means of taxonomic work based on morphology and genetic analyses. Geographical ranges of species should be revised in order to eliminate false conclusions about distributions of species. 53 Acknowledgments The Harte Research Institute is thanked for providing office space and computational resources. The College of Science and Engineering at Texas A&M University – Corpus Christi is thanked for the support through teaching assistantships from fall semester 2008 to spring semester 2011. Paul Montagna is thanked for his support through a research assistantship since the fall semester 2011. Support for the summer semesters of the years 2010-2013 was provided through MARB scholarships by the College of Science and Engineering at Texas A&M University – Corpus Christi. 54 TABLE 1.1 Geographical and depth records, data on ecological guilds, and worldwide distribution of Gulf of Mexico polychaetes. Abbreviations are explained under Materials & Methods. Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D D SD PA EN M CV AP AM M CV AP WA Aberrantidae Aberranta palpata X X Acoetidae 55 Acoetes pacifica X X Acoetes pleei X X Euarche mexicana X X Euarche tubifex X X Eupolyodontes batabanoensis Panthalis alaminosae Polyodontes frankenbergi X X X X X X X X X X ? X X M CV AP EN X X X M CV AP WD ? ? ? M CV AP WA M CV AP SW M CV AP NW X X X X X ? ? Comments TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Polyodontes frons X X Polyodontes lupinus X X Polyodontes texanus X SW SE D1 D2 D3 D4 D5 D6 M F A D M CV AP AM M CV AP AM M CV AP EN X M SD PP WD X X X X X Comments Acrocirrus frontifilis X X Macrochaeta cf. clavicornis X X M SD PP X X S SD TE S SD TE HA Ampharetidae Ampharete cf. acutifrons Ampharete lindstroemi X Ampharete parvidentata Amphicteis gunneri X X X X ? ? ? ? ? ? X X X S SD TE NW X X X S SD TE AM 56 Acrocirridae TABLE 1.1 (continued) Family Species Amphicteis scaphobranchiata Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X Asabellides species indet. X Hobsonia florida X Isolda pulchella X 57 Melinna cristata X X X X X Melinna maculata X X Paralysippe cf. annectens X X Sabellides octocirrata Sosane sulcata SE D1 M F A D S SD TE WD X S SD TE X S SD TE AM X S SD TE WD X S SD TE WD S SD TE WA X S SD TE X S SD TE HA X S SD TE AT M CV R WD X X D2 D3 X X X X D5 D6 X X X X D4 X Amphinomidae Amphinome rostrata X X X ? ? ? ? ? ? Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X Eurythoe complanata X X Eurythoe paupera X Chloeia viridis Hermodice carunculata X X X Hipponoe gaudichaudi X Linopherus ambigua X Linopherus paucibranchiata X Paramphinome jeffreysii Pareurythoe americana Aphroditidae X X X D1 D2 D3 X X X X ? ? ? X X ? ? X X X ? X X Paramphinome pulchella SE X X X X X X D4 ? ? D5 ? ? D6 ? ? M F A D M CV R WD M CV R WD M CV R AM M CV R WD M CV R AT M CV R AM M CV R WD M CV R AT M CV R AT M CV R SW Comments Includes records of junior synonym C. euglochis 58 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 X D5 D6 M F A M CV AP D 59 Aphrodita species indet. X Aphrogenia alba X X M CV AP WD Pontogenia curva X X M CV AP AM Pontogenia sericoma X X M CV AP AT X X D DS PP D SS UP X M SS UP X M SS UP Apistobranchidae Apistobranchus species indet. X Arenicolidae Arenicola cristata X Barantolla cf. lepte X X WD Capitellidae Capitella capitata X X X X WD Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X Dasybranchus lunulatus X X Decamastus gracilis X X Heteromastus filiformis X X Dasybranchus caducus lumbricoides Leiocapitella glabra SE X D1 D2 D3 X X X X X X X Leiochrides pallidior X Mastobranchus variabilis X Mediomastus ambiseta X X X X X Mediomastus californiensis X X X Notomastus daueri X X X Notomastus hemipodus X X X D4 D5 D6 M F A D M SS UP WD M SS UP WA M SS UP AM M SS UP WD M SS UP WD M SS UP AM M SS UP NW M SS UP AM M SS UP WD X X X X X X M SS UP SW X X X X M SS UP WD Comments Listed as Dasybranchus lumbricoides 60 TABLE 1.1 (continued) Includes records of junior synonym N. americanus TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Notomastus latericeus X Notomastus lineatus X X SE D1 D2 D3 X X X X X D4 D5 D6 M F A D M SS UP WD M SS UP WD 61 Notomastus lobatus X X X X X X M SS UP AM Notomastus tenuis X X X X X X M SS UP AM Peresiella spathulata X X X M SS UP SW Scyphoproctus platyproctus X X M SS UP SW X S SU PU WD Chaetopteridae Chaetopterus variopedatus X Mesochaetopterus capensis X X S DS PA WD X S DS PA AM S DS PA WD Mesochaetopterus taylori X X Spiochaetopterus costarum X X X X X X X X Comments TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NE SW X X Arichlidon gathofi X X Bhawania goodei X X Spiochaetopterus costarum oculatus NW SE D1 D2 D3 X X X D4 D5 D6 M F A D X S DS PA WA X M OV AP WA M OV AP WA M OV AP NW M OV AP NW M OV AP NW M OV AP WD M OV AP AT M OV AP NW M OV AP WD Comments Chrysopetalidae X Chrysopetalum floridanum Chrysopetalum hernancortezae X X X Chrysopetalum occidentale Dysponetus caecus X Hyalopale bispinosa Paleanotus chrysolepis X X X X X X X X X X X X X X X X X X X Includes rec. of junior syn. Chrysopetalum elegans 62 Bhawania heteroseta X Listed as Chrysopetalum caecum TABLE 1.1 (continued) Family Species Paleaquor heteroseta Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE X X X X SW SE D1 D2 X D3 D4 D5 D6 M F A D X M OV AP NW X M SD PP Comments Cirratulidae Aphelochaeta cf. filiformis Listed as Cirratulus cf. filiformis 63 Aphelochaeta monilaris X ? ? ? ? ? ? M SD PP AM Aphelochaeta phillipsi X ? ? ? ? ? ? M SD PP AM Aphelochaeta williamsae X ? ? ? ? ? ? M SD PP AM X M SD PP WD X M SD PP AT X M SD PP AT Caulleriella alata X Caulleriella killariensis X Caulleriella zetlandica X X X Chaetozone commonalis X ? ? ? ? ? ? M SD PP AM Chaetozone columbiana X ? ? ? ? ? ? M SD PP AM Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Chaetozone setosa X Cirratulus grandis X SW X SE X D1 D2 X X D3 D4 D5 D6 X M F A D M SD PP WD M SD PP NW Cirriformia capensis X ? ? ? ? ? ? M SD PP AT Cirriformia filigera X ? ? ? ? ? ? M SD PP WD Cirriformia punctata X ? ? ? ? ? ? M SD PP WD M SD PP NW M SD PP WD M SD PP NW M SD PP WD M SD PP WD M SD PP Dodecaceria coralii X Dodecaceria fistulicola X Monticellina baptisteae Monticellina dorsobranchialis X Monticellina tesselata Tharyx cf. annulosus X X X X X ? ? ? X X X ? ? ? X X X ? ? ? ? ? ? Comments 64 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Tharyx marioni X Tharyx setigera X SW SE D1 D2 D3 D4 D5 D6 M F A D M SD PP WD M SD PP NW X M SS UP WD X M SS UP WD X M SS UP EN X M SS UP AT M OV AP EN M OV AP AM M OV AP EN X X Comments Cossuridae Cossura delta X 65 Cossura longocirrata X X X X X X Cossura pseudakaina X Cossura soyeri X X X X X X Dorvilleidae Diaphorosoma magnavena X Dorvillea cerasina Dorvillea clavata X X X X ? ? X ? ? ? ? Listed as Cossurella pseudakaina Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Dorvillea jumarsii X Dorvillea largidentis X Dorvillea rubra Dorvillea sociabilis X Eliberidens forceps X Meiodorvillea species indet. SE D1 D2 D3 D4 D5 D6 M F A D M OV AP AM M OV AP EN M OV AP SW M OV AP WA X M OV AP EN X M OV AP X X X ? ? X X X ? ? ? ? X X Ophryotrocha species indet. X X M OV AP Ougia tenuidentis X X M OV AP EN Pettiboneia blakei X X M OV AP EN X X M OV AP NW X X M OV AP NW Pettiboneia duofurca Protodorvillea bifida X SW X X Comments 66 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NE SW SE D1 D2 D3 Protodorvillea kefersteini X X X X X X Schistomeringos longicornis X X X Schistomeringos pectinata NW X Schistomeringos perkinsi X X X X 67 Schistomeringos cf. rudolphii X X Westheideia minutimala X X X X X X D4 D5 D6 M F A D M OV AP WD M OV AP AM M OV AP NW M OV AP EN X X M OV AP X X M OV AP EN X M CV AP AT Eulepethidae Grubeulepis augeneri X X X X Grubeulepis ecuadorensis X X X X M CV AP AM Grubeulepis fimbriata X X M CV AP SW X M CV AP AM Grubeulepis mexicana X X X X Comments TABLE 1.1 (continued) Family Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties Species NW NE Grubeulepis westoni X Lamelleulepethus biminiensis D2 D3 X X X X X Mexieulepis elongatus SW SE D1 X X X X X X D4 D5 D6 M F A D M CV AP WA M CV AP NW M CV AP WA D OV AP WD X D OV AP SW X D OV AP WD X D OV AP NW X D OV AP SW D OV AP WA D OV AP WA Comments Listed as M. weberi Eunice antennata Eunice antipathum X X Eunice aphroditois X Eunice articulata Eunice cariboea X X X X Eunice denticulata Eunice filamentosa X X X X X X X X X X 68 Eunicidae TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Eunice floridana Eunice fucata X Eunice macrobranchia Eunice mutilata 69 Eunice norvegica Eunice pennata X X Eunice schemacephala D1 D2 D3 D6 M F A D D OV AP AT X X D OV AP WA X X D OV AP WA X X D OV AP AM D OV AP AT D OV AP WD D OV AP SW D OV AP WA D OV AP WD X X X X X X D5 X X X D4 X X Eunice riojai Eunice rubra SE X X X X X X X X X Eunice stigmatura X ? ? ? ? ? ? D OV AP WA Eunice tenuicirrata X ? ? ? ? ? ? D OV AP WA Comments Senior synonym of Eunice longisetis Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Eunice tenuis NE SW X X SE D1 D2 X X D3 D4 D5 D6 M F A D D OV AP NW Eunice tibiana X ? ? ? ? ? ? D OV AP SW Eunice unifrons X ? ? ? ? ? ? D OV AP WA Eunice violaceomaculata X ? ? ? ? ? ? D OV AP WA X X D OV AP WD X D OV AP WA X D OV AP EN Eunice vittata X X Eunice websteri X X Eunice weintraubi X Eunice wui X X Euniphysa quadridentata X X Euniphysa tridontesa Lysidice ninetta X X X X X X X ? X X D OV AP EN X X M OV AP EN ? ? M OV AP WD X X M OV AP WD ? ? ? Comments 70 TABLE 1.1 (continued) Includes records of junior synonym E. antillensis TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Marphysa angelensis SW SE X Marphysa bellii X X Marphysa cf. conferta X X 71 Marphysa disjuncta X Marphysa kinbergi X D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M OV AP AM X X M OV AP WD X X M OV AP M OV AP WD M OV AP WD X X X X Marphysa longula X ? ? ? ? ? ? M OV AP SW Marphysa minima X ? ? ? ? ? ? M OV AP SW M OV AP WD M OV AP WA Marphysa mortenseni X X Marphysa regalis X ? ? ? ? ? ? Marphysa sanguinea X X X X X X M OV AP WD Nematonereis hebes X X X X X X M OV AP WD Comments Senior synonym of M. fragilis TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Nematonereis unicornis Palola siciliensis NE SW X X X X SE D1 D2 D3 M F A D M OV AP WD M OV AP WD X M CV R WD X M CV R WA X D DS FP AT D DS FP EN D DS FP SW X M DS TE WD Listed in Sabellidae X D DS FP AT Listed in Sabellidae X X X D4 D5 D6 Comments Euphrosine armadilloides X Euphrosine triloba X Fabricia sabella X Fabricinuda pseudocollaris X X 72 Euphrosinidae Fabriciidae Fabricinuda trilobata Manayunkia aestuarina Novafabricia infratorquata X X X X X X X X X Listed in Sabellidae Listed in Sabellidae; depth record from Fitzhugh (1990) Listed as Fabriciola trilobata; listed in Sabellidae TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Pseudofabriciola sofla NE SW SE D1 D2 M F A D D DS FP EN M SS UP D SD PA WD D SD PA WD X M SD PA X D SD PA AM M SD PA SW M SD PA NW M SD PA EN X X X X D3 D4 D5 D6 Fauveliopsidae Fauveliopsis species indet. X Flabelligeridae 73 Brada villosa X X X Diplocirrus capensis X X Flabelligera species indet. X Pherusa inflata X Piromis cariboum Piromis roberti X X X X Piromis eruca websteri X ? X X X ? X ? X X X X X ? ? ? Comments Listed in Sabellidae TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Therochaeta species indet. NE SW SE D1 D2 M F A D SD PA D OV AP SW D OV AP WD D OV AP WD X D OV AP WD X X D OV AP AM D OV AP EN D OV AP WD D OV AP WD D OV AP WD X X X D3 D4 D5 D6 D Comments Glycera abranchiata X X Glycera americana X X Glycera brevicirris X X X X X ? ? Glycera capitata X Glycera dibranchiata X X X X X X X ? ? Glycera gilbertae X Glycera lapidum Glycera oxycephala X Glycera papillosa X X X ? ? X X X X ? ? ? ? ? ? 74 Glyceridae Depth record from Böggemann & Fiege (2001) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Glycera pseudorobusta SW SE X D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? D OV AP NW X D OV AP AM D OV AP WA D OV AP WD D OV AP WD D OV AP AM D OV AP AT D OV AP AM X D OV AP AM X D OV AP AM Glycera robusta X Glycera sphyrabrancha X X X X X X Glycera tesselata 75 D1 X Hemipodia simplex X X X X ? ? ? X X X X X ? ? ? Goniadidae Glycinde armigera Glycinde nordmanni X X Glycinde pacifica Glycinde solitaria Goniada acicula X X X X ? ? ? ? ? ? Comments Senior synonym of H. roseus Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Goniada brunnea NE SW SE D1 X D2 D3 X D4 D5 D6 M F A D D OV AP WD Goniada littorea X X X X X D OV AP AM Goniada maculata X X X X X D OV AP WD D OV AP WD Goniada norvegica X X Goniada teres X X X Goniadides carolinae X X X Ophiogoniada lyra Progoniada species indet. X X X X X D OV AP WA X X D OV AP WA X D OV AP EN X D OV AP M OV AP Hartmaniellidae Hartmaniella species indet. Hesionidae X X Comments 76 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Amphiduros species indet. Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE X X Gyptis crypta SW SE X D1 D2 D3 X X D4 D5 D6 M F A M CV UP M CV UP NW M CV UP EN X M CV UP SW X Hesiocaeca methanicola X 77 Hesione picta X Hesiospina species indet. X X M CV UP Heteropodarke formalis X X M CV UP X X M CV UP X X M CV UP NW M CV UP AT M SS UP NW M SS UP AT Heteropodarke cf. heteromorpha Heteropodarke lyonsi Kefersteinia cirrata X X X X X X D X X X X Microphthalmus hamosus X X X X Microphthalmus sczelkowii X ? ? ? X ? ? ? WA Comments Includes records of junior synonym H. proctochona TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D Comments Listed as Gyptis plurisetis, Neogyptis plurisetis X X X X M CV UP EN taxonomy changed according to Nereimyra species indet. X X Oxydromus agilis X Oxydromus guanicus X Oxydromus mutilatus X Oxydromus obscurus X Parahesione luteola X Podarkeopsis brevipalpa Podarkeopsis levifuscina Lacydoniidae X X X M CV AP X M CV UP SW Listed as Ophiodromus agilis X M CV UP AT Listed as Ophiodromus guanicus M CV UP SW M CV UP WA M CV UP NW M CV UP AM M CV UP NW ? ? ? X X X X X X X X X X X X X X ? ? ? Listed as Ophiodromus mutilatus Listed as Ophiodromus obscurus 78 Pleijel et al. (2012) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Lacydonia miranda NE SW SE D1 D2 D3 D4 D5 D6 M F A D Comments X X M OV UP AT Levidorum hartmanae X X M SD UP EN Listed in Sphaerodoridae Levidorum pettiboneae X X M SD UP EN Listed in Sphaerodoridae X X D DS PP AM X D DS PP X M OV AP Levidoriidae 79 Longosomatidae Heterospio catalinensis Heterospio cf. longissima X X X X Lumbrineridae Cenogenus brevipes X X WD Listed as Lumbrinerides Lumbricalus januarii X X X M OV AP WA januarii; includes records of junior synonym L. dayi Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Lumbrinerides aberrans SW X Lumbrinerides acuta X Lumbrinerides crassicephala X Lumbrinerides jonesi X Lumbrineriopsis paradoxa X X X X Lumbrineris coccinea Lumbrineris floridana X X X D3 D4 D5 D6 M F A D ? ? ? ? ? ? M OV AP AT X X M OV AP WD ? ? M OV AP NW X X M OV AP WD ? ? M OV AP NW X M OV AP EN X X M OV AP AT X X M OV AP NW ? ? M OV AP WD X X M OV AP WD ? ? M OV AP SW X Lumbrinerides uebelackerae Lumbrineris cingulata D2 ? X X D1 X X Lumbrinerides dayi Lumbrineris bidens SE ? X ? X X ? ? ? ? ? ? ? ? ? ? ? ? ? Comments 80 TABLE 1.1 (continued) Listed as Augeneria bidens TABLE 1.1 (continued) Family Species Lumbrineris inflata Lumbrineris latreilli Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 X X X X X X X X X X ? Lumbrineris limicola X 81 Lumbrineris nonatoi X Lumbrineris parvapedata X Lumbrineris perkinsi X M F A D X M OV AP WD X X M OV AP WD ? ? M OV AP AM M OV AP AT M OV AP WD M OV AP SW M OV AP SW ? D5 ? D6 ? X ? X D4 ? ? ? ? ? X Lumbrineris salazari X Lumbrineris tetraura X X M OV AP WD Lysarete brasiliensis X X M OV AP AM Lysarete raquelae X X M OV AP NW M OV AP SW Ninoe brasiliensis X X X ? ? X ? ? ? ? Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D Ninoe leptognatha X ? ? ? ? ? ? M OV AP AM Ninoe nigripes X ? ? ? ? ? ? M OV AP NW M OV AP EN X M OV AP EN X X M OV AP SW X X M OV AP WA M OV AP AM M OV AP NW M OV AP SW M OV AP SW M OV AP WA Ninoe vargasi X X X Ninoe wardae X Scoletoma candida X X X X Scoletoma ernesti X Scoletoma minima X X ? ? ? X X Scoletoma tenuis X X X Scoletoma testudinum X X X X ? Scoletoma treadwelli Scoletoma verrilli X X X X ? ? X X ? ? ? ? ? ? Comments 82 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE X X SW SE D1 D2 X D3 D4 D5 D6 M F A X D SD PP X D SD PP D Comments Magelonidae Magelona cf. cincta Magelona cf. cornuta X 83 Magelona pettiboneae X X X X X D SD PP SW Magelona phyllisae X X X X X D SD PP AM Magelona polydentata X X X D SD PP WA Magelona riojai X X D SD PP SW Magelona rosea X D SD PP NW D SD PP AM D SD PP EN Magelona spinifera Magelona uebelackerae Maldanidae X X X X X X X X X Listed as Meredithia spinifera Listed as Meredithia uebelackerae Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D S SS UP NW NW Asychis carolinae X X Boguea enigmatica X X X X S SS UP Boguella species indet. X X X X S SS UP Clymenella mucosa X S SS UP NW S SS UP AT Clymenella torquata X X X X X X X X X S SS UP X S SS UP NW S SS UP WD X S SS UP WD X S SS UP S SS UP Euclymene species indet. X Macroclymene zonalis X Maldane glebifex X X Maldane sarsi X X Praxillella species indet. X Sabaco elongatus X X X X X X X X AM Comments Listed as Axiothella mucosa 84 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D Comments Nautiliniellidae Flascarpia alvinae X X S C UP EN Laubierus mucronatus X X S C UP EN Nephtyidae 85 Aglaophamus circinata X X X Aglaophamus verrilli X X X Inermonephtys inermis X X X Micronephthys minuta X X Nephtys bucera X Nephtys cryptomma X X Nephtys incisa X X X X X X X X X X M OV AP NW X X M OV AP WD X X M OV AP WD X X M OV AP HA X M OV AP NW X M OV AP NW M OV AP AT X X Depth record from Blake (1993) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Nephtys magellanica SW SE X Nephtys picta X X Nephtys simoni X X X X X X X Nephtys squamosa D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M OV AP AM X X M OV AP AM X X M OV AP AM X X M OV AP AM X X X D OV AP WD Listed as Neanthes succinea ? ? ? D OV AP WD Listed as Neanthes virens X D OV AP AM X D OV AP WA D OV AP WA D OV AP WD X Comments 86 Nereididae Alitta succinea X Alitta virens X Ceratocephale oculata X X X Ceratonereis irritabilis X X X X X X X Ceratonereis longicirrata Ceratonereis mirabilis X X X X X X X ? ? ? TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Ceratonereis singularis Ceratonereis versipedata X Gymnonereis crosslandi X Laeonereis culveri X SW SE D1 D2 X X X X D3 D4 D5 D6 87 M F A D X D OV AP AM X D OV AP WA D OV AP AM D OV AP WA WD X X X X Leonnates decipiens X X D OV AP Leptonereis species indet. X X D OV AP Namalycastis borealis X X D OV AP WA X D OV AP EN D OV AP AM D OV AP WD D OV AP WD Namalycastis intermedia X Neanthes acuminata X X Neanthes caudata Nereis falsa X X X X ? X ? ? X X X ? ? ? Comments Family Species Nereis grayi Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X Nereis jacksoni SE D1 D2 D3 X X ? X ? ? D4 ? D5 ? D6 ? M F A D D OV AP WD D OV AP NW Nereis lamellosa X X X X X D OV AP WD Nereis micromma X X X X X D OV AP WD Nereis oligohalina X ? ? ? ? ? ? D OV AP AM Nereis panamensis X ? ? ? ? ? ? D OV AP SW Nereis pelagica X ? ? ? ? ? ? D OV AP AM ? ? ? ? ? ? D OV AP WD X X X D OV AP WA ? ? ? D OV AP AM X X D OV AP WD Nereis pelagica occidentalis X X Nereis riisei X X Nicon aestuarensis Nicon moniloceras X X X X ? ? ? Comments Listed as Neanthes micromma 88 TABLE 1.1 (continued) Listed as Nereis aestuarensis TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Perinereis anderssoni SW SE X D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? D OV AP WA D OV AP EN Perinereis cariboea X X Perinereis cultrifera X ? ? ? ? ? ? D OV AP WD X ? ? ? ? ? ? D OV AP AM X ? ? ? ? ? ? D OV AP SW X ? ? ? ? ? ? D OV AP X X X D OV AP WD X D OV AP EN X D OV AP EN D OV AP WD D OV AP AM Perinereis elenacasoi X 89 Perinereis floridana X Perinereis cf. vancaurica Platynereis dumerilii X X X Platynereis hutchingsae X Platynereis mucronata X Pseudonereis gallapagensis X Rullierinereis mexicana X X X ? ? X ? ? ? ? Comments Depth record from de León González & Solís-Weiss (1998) Depth record from de León González et al. (2001) Depth record from de León González et al. (2001) TABLE 1.1 (continued) Family Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties Species NW NE SW Stenoninereis martini X X Stenoninereis tecolutlensis Websterinereis tridentata X D1 D2 D3 D4 D5 D6 M F A D X ? ? ? ? ? ? D OV AP SW X X D OV AP EN X X X X SE X X D OV AP NW X X M OV AP WD X M OV AP WD M SD AP Comments Includes records of junior synonym Nicon lackeyi Depth record from de León González & Solís-Weiss (1997) Oenonidae X Arabella mutans X X X Drilonereis cf. debilis X X X Drilonereis falcata X ? ? ? ? ? ? M SD AP AM Drilonereis filum X ? ? ? ? ? ? M SD AP WD X X X X M SD AP AM M SD AP NW Drilonereis longa Drilonereis magna X X X X Includes records of junior synonym A. multidentata 90 Arabella iricolor TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NE SW SE Drilonereis spatula X X X Labrorostratus luteus X Notocirrus species indet. NW X Oenone fulgida D1 D2 91 M F A D M SD AP SW X M CV AP NW X M OV AP X X M OV AP WD ? ? D OV AP WA X D OV AP WD AM X X D4 D5 D6 X X X D3 X Onuphidae Americonuphis magna X ? ? ? ? Diopatra cuprea X X X X Diopatra neotridens X X X X D OV AP Diopatra cf. papillata X X X X D OV AP Diopatra tridentata X X X X D OV AP AM Hyalinoecia tubicola X X X M OV AP WD X X X Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D Kinbergonuphis cedroensis X ? ? ? ? ? ? D OV AP AM Kinbergonuphis oligobranchiata X ? ? ? ? ? ? D OV AP SW Kinbergonuphis orensanzi X ? ? ? ? ? ? D OV AP SW X X D OV AP NW X D OV AP AM D OV AP AM Kinbergonuphis simoni X Kinbergonuphis virgata X X X X Mooreonuphis dangrigae X X Mooreonuphis nebulosa X X X X X D OV AP AM Mooreonuphis pallidula X X X X X D OV AP WA ? ? D OV AP AM D OV AP NW D OV AP WD Mooreonuphis stigmatis X Nothria textor X Onuphis eremita X ? ? X X ? ? Comments Listed as Onuphis virgata 92 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Onuphis eremita oculata X X X Onuphis texana X Paradiopatra hartmanae X SE X X X ? 93 X Rhamphobrachium diversosetosum Rhamphobrachium brevibrachiatum D2 D3 X X D4 D5 D6 X Paradiopatra cf. papillata Rhamphobrachium atlanticum D1 X X X X ? ? ? ? X ? M F A D D OV AP AT D OV AP EN D OV AP WD D OV AP D OV AP AT X X D OV AP WD X X D OV AP WD Opheliidae Armandia agilis X X X X X X X M SS UP WA Armandia maculata X X X X X X X M SS UP WD X X M SS UP AT Ophelia denticulata X Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Ophelina acuminata X X Ophelina cylindricaudata X Polyophthalmus pictus Tachytrypane jeffreysii X Travisia hobsonae X SE D1 X D2 D3 X X X X X X ? ? X X X M F A D X M SS UP WD X M SS UP WD M SS UP WD M SS UP AT M SS UP AM M SS UP AM ? D4 ? D5 ? D6 ? Orbiniidae Califia calida X X X Leitoscoloplos foliosus X X X X X M SS UP SW Leitoscoloplos fragilis X X X X X M SS UP WD X X X X M SS UP WA M SS UP EN Leitoscoloplos robustus Methanoaricia dendrobranchiata X X X X Comments 94 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Naineris bicornis Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X SE D1 D2 D3 D4 D5 D6 M F A D X M SS UP EN Naineris dendritica X X M SS UP AM Naineris grubei X X M SS UP WD X X M SS UP WD ? ? ? M SS UP AT X X M SS UP NW M SS UP AM M SS UP WD M SS UP AM M SS UP M SS UP Naineris laevigata X 95 X X X X X X Orbinia riseri X X X X Phylo felix X X ? ? Phylo ornatus X Proscoloplos species indet. X Naineris setosa Orbinia americana Protoaricia oerstedii X X ? ? ? ? ? ? ? X X X ? ? ? ? ? ? AT Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D Questa caudicirra X X M SS UP NW Questa trifurcata X X M SS UP WD Scoloplos acmeceps X X X M SS UP AM Scoloplos capensis X X X M SS UP AT M SS UP AM Scoloplos latum X ? ? ? X X X M SS UP AM M SS UP AM M SS UP AM S SD LI HA S DS PA AM Scoloplos rubra X X X Scoloplos texana X X X X X X X ? ? ? X X X Scoloplos treadwelli X X ? ? ? ? ? ? Comments Listed in Questidae Listed as Novaquesta trifurcata; listed in Questidae 96 TABLE 1.1 (continued) Oweniidae Galathowenia oculata X Myriowenia californiensis X X X X Listed as Myriochele oculata TABLE 1.1 (continued) Family Species Owenia fusiformis Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X X X X X X SE D1 D2 X X D3 D4 D5 D6 M F A D Comments S DS LT WD M OV UP WD M SS UP M SS UP EN Listed as Allia bryani Paralacydoniidae Paralacydonia paradoxa X Paraonidae 97 Aricidea cf. alisdairi Aricidea bryani Aricidea catherinae X Aricidea cerrutii X X X X X X M SS UP WD Listed as Acmira catherinae X X X M SS UP AT Listed as Acmira cerrutii M SS UP AT X M SS UP X M SS UP Aricidea claudiae X Listed as Allia cf. alisdairi X Aricidea cf. finitima X X X Aricidea fragilis X X X ? X X ? ? ? ? ? Listed as Acmira cf. finitima WD TABLE 1.1 (continued) Species Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Aricidea longicirrata SW SE X D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M SS UP AM X M SS UP WD Aricidea lopezi X X Aricidea cf. minima X X M SS UP Aricidea cf. minuta X X M SS UP Comments Listed as Acmira lopezi Aricidea mirifica X ? ? ? ? ? ? M SS UP WD Aricidea nolani X ? ? ? ? ? ? M SS UP HA X M SS UP WA Listed as Acmira philbinae X M SS UP X M SS UP WD Listed as Allia quadrilobata X M SS UP WD Listed as Acmira simplex M SS UP WD Listed as Allia suecica Aricidea philbinae X Aricidea cf. pseudoarticulata X Aricidea quadrilobata X Aricidea simplex X Aricidea suecica X X X X X X X 98 Family Presence data of the TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Aricidea taylori X X X Aricidea cf. trilobata X X Aricidea wassi Cirrophorus americanus X X SE D1 D2 D4 D5 D6 X X X D3 X X X X M F A D M SS UP SW M SS UP M SS UP WD 99 X X M SS UP WA X M SS UP WD X X X Cirrophorus cf. furcatus X X X M SS UP X X X M SS UP X M SS UP M SS UP SW M SS UP WD M SS UP X Levinsenia cf. multibranchiata Levinsenia reducta X X X Paradoneis armata Paradoneis cf. forticirrata X X X X ? X X ? ? X X ? ? ? Listed as Acmira taylori Listed as Allia cf. trilobata Cirrophorus branchiatus Levinsenia gracilis Comments WD Listed as Cirrophorus armatus Listed as Cirrophorus cf. forticirratus Family Species Paradoneis lyra Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW X X X SE D1 X D2 D3 D4 D5 D6 M F A D X M SS UP WD X M SS UP AT X M SS UP EN X M SS UP WA WA Paradoneis perdidoensis X Paradoneis perkinsi X Paraonis fulgens X Paraonis pygoenigmatica X X M SS UP X D SS TE X X D SS TE WA D SS TE WA X Pectinariidae Amphictene species indet. X X Pectinaria gouldii X X X Pectinaria regalis X X X X X Petta pusilla X ? ? ? ? ? ? D SS TE HA Petta tenuis X ? ? ? ? ? ? D SS TE WD X Comments Listed as Cirrophorus lyra Listed as Cirrophorus perdidoensis Listed as Cirrophorus perkinsi 100 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 X D4 D5 D6 M F A D M CV AP EN M CV AP WD M CV AP WD M CV AP WA M OV UP AT M OV UP HA M OV UP WD M OV UP AM M OV UP WD Comments Pholoidae 101 Metaxypsamma uebelackerae X X Pholoe minuta X X Pholoides dorsipapillatus X Taylorpholoe hirsuta X X X Phyllodocidae Eteone lactea X X Eteone longa X X ? Eulalia bilineata X X Eulalia myriacyclum X X X X X X Eumida sanguinea X X X ? ? X X X ? ? ? Listed in Sigalionidae Senior synonym of P. bermudensis Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Hesionura coineaui SE X Hesionura elongata Hypereteone heteropoda SW D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M OV UP AT M OV UP AT M OV UP WA X X X X X X X X Mystides borealis X X M OV UP WD Nereiphylla castanea X X M CV UP WD Nereiphylla fragilis X X X M CV UP NW Paranaitis gardineri X X X M CV UP NW M CV UP WD M CV UP WA M CV UP NW M CV UP SW Paranaitis polynoides X X X Paranaitis speciosa X X Phyllodoce arenae X X Phyllodoce erythrophylla X X X X X X X ? ? ? ? ? ? Comments Listed as Eteone heteropoda 102 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 Phyllodoce groenlandica X X X Phyllodoce longipes X X X Phyllodoce madeirensis X X X X Phyllodoce mucosa X X X X 103 Phyllodoce panamensis X Protomystides bidentata X Pterocirrus macroceros X ? D3 D4 M F A D M CV UP HA X M CV UP WD X M CV UP WD M CV UP HA M CV UP AM M OV UP AT ? D5 ? D6 ? ? ? X X X X X M OV UP AT X M CV UP NW M CV UP NW M CV UP WD Pilargidae Ancistrosyllis carolinensis Ancistrosyllis commensalis Ancistrosyllis groenlandica X X X X X X X Comments Senior synonym of P. composa Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Ancistrosyllis hamata NE SW SE D1 D2 X X X D3 D5 D6 M F A D M CV UP WD M CV UP AM Ancistrosyllis hartmanae X X Ancistrosyllis jonesi X X X X M CV UP AM Ancistrosyllis papillosa X X X X M CV UP AM X X X M CV UP AM X X M CV UP AT Cabira incerta X Glyphohesione klatti X X X D4 Comments 104 TABLE 1.1 (continued) Listed as Synelmis klatti Listed as Parandalia fauveli; Hermundura fauveli X X X X M CV UP AM Hermundura tricuspis X X X X M CV UP SW Listed as Parandalia tricuspis X X M CV UP EN Listed as Parandalia vivianneae M CV UP SW M CV UP AM Hermundura vivianneae Litocorsa antennata Pilargis berkeleyi X X X X X X X includes rec. of H. americana TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Pilargis pacifica NE SW SE X X 105 D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M CV UP WD X X M CV UP AM M CV UP WD M CV UP NW M CV UP SW X M CV UP X M CV UP EN M CV UP SW D DS PP WD Sigambra bassi X X Sigambra tentaculata X X X X Sigambra wassi X X X X Synelmis acuminata X X X Synelmis cf. albini X X Synelmis ewingi X X Synelmis sotoi X X X X X X Poecilochaetidae Poecilochaetus johnsoni Polynoidae X X X X X X Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 M F A D X M CV AP WD M CV AP M CV AP EN M CV AP AT M CV AP SW M CV AP WA M CV AP WD M CV AP SW M CV AP WA Admetella longipedata X Arctonoe species indet. X X X X Branchipolynoe seepensis X Eunoe hubrecthi X X D4 X Harmothoe aculeata X Harmothoe spinifera X X ? X X ? ? ? ? ? X X X Hermenia verruculosa X D6 X Halosydna leucohyba Harmothoe trimaculata D5 ? X ? ? ? ? ? X Lepidametria commensalis X ? ? ? ? ? ? M CV AP NW Lepidametria lactea X ? ? ? ? ? ? M CV AP EN Comments 106 TABLE 1.1 (continued) Listed as Lepidasthenia lactea TABLE 1.1 (continued) Family Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties Species NW Lepidasthenia varius X NE SW X X Lepidonotus variabilis 107 X X X X X Malmgreniella maccraryae X X Malmgreniella pierceae X X Malmgreniella puntotorensis Malmgreniella taylori D1 X Lepidonopsis humilis Lepidonotus sublevis SE X ? X X Malmgreniella variegata X M F A D X M CV AP EN X M CV AP AM X M CV AP NW M CV AP WA X M CV AP NW X M CV AP NW M CV AP SW X M CV AP WA X M CV AP AM ? X X X D2 X D3 ? D4 ? D5 ? D6 ? Perolepis species indet. X X M CV AP Phyllohartmania taylori X X M CV AP EN Comments Listed as Lepidonotus humilis TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Subadyte pellucida NE SW SE D1 X D2 D3 D4 D5 D6 M F A D M CV AP WD M CV AP AM S SU FI WD S SU FI EN S SU FI SW X S SU FI WA X S SU FI NW X Thormora johnstoni X X Comments Lygdamis indicus X Phalacrostemma gloriaae X Phragmatopoma caudata Sabellaria floridensis X X X ? X Sabellaria vulgaris X Tetreres varians X X ? ? ? ? ? ? ? ? ? ? ? S SU FI SW ? ? ? ? ? ? S SU FI SW Sabellidae Anamobaea oerstedi X 108 Sabellariidae Senior synonym of P. lapidosa TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Bispira brunnea SW SE X D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? S SU FI WA Comments Includes records of junior Bispira melanostigma X X X X X X S SU FI AM synonym Sabella variegata (according to Knight-Jones & Perkins (1998)) Branchiomma arenosa X 109 Branchiomma bairdi X Branchiomma conspersum X ? ? ? ? ? ? S SU FI SW ? ? ? ? ? ? S SU FI WD ? ? ? ? ? ? S SU FI SW Branchiomma nigromaculatum X ? ? ? ? ? ? S SU FI WD Chone duneri X ? ? ? ? ? ? S SU FI HA S SU FI X S SU FI X S SU FI Dialychone species indet. Euchone cf. incolor Euchone cf. southerni X X X X X X Listed as Bispira nigromaculata Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D S SU FI WD Hypsicomus phaeotaenia X X Jasmineira cf. pacifica X X X S SU FI X X S SU FI AT X S SU FI WA X X S SU FI SW X X X S SU FI AM ? ? S SU FI WD S SU FI WD S SU FI SW S SU FI AM S SU FI AM Megalomma bioculatum X X Megalomma heterops X Megalomma lobiferum X X Megalomma pigmentum X X Megalomma quadrioculatum Megalomma vesiculosum Notaulax occidentalis X X X X Notaulax circumspiciens Notaulax nudicollis X ? X X X ? ? X X X ? ? X ? ? ? ? ? X ? ? ? ? ? ? Comments 110 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Oriopsis anneae Panousea africana X X Paradialychone uebelackerae X X 111 Parasabella lacunosa X X X ? X X X X Potamethus spathiferus X X X X Pseudobranchiomma emersoni X X X X D3 D4 ? D5 ? D6 ? X X M F A D S SU FI SW S SU FI AT Comments ? ? X X S SU FI AM Listed as Chone americana X X S SU FI EN Listed as Chone uebelackerae S SU FI NW Listed as Demonax lacunosus S SU FI WD S SU FI AT X X X X Pseudopotamilla oculifera D2 X X Potamilla torelli Pseudopotamilla reniformis D1 X Paradialychone americana Parasabella microphthalma SE ? ? ? ? ? ? S SU FI WD ? ? ? ? ? ? S SU FI WA ? ? ? ? ? ? S SU FI NW X X S SU FI WD Listed as Demonax microphthalmus Listed as Potamilla reniformis TABLE 1.1 (continued) Family Species Pseudopotamilla tortuosa Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 X D2 D3 D4 D5 D6 X M F A D S SU FI NW Comments Sabellastarte magnifica X ? ? ? ? ? ? S SU FI WD Sabellastarte spectabilis X ? ? ? ? ? ? S SU FI WD Senior synonym of S. indica ? ? ? ? ? ? S SU FI SW Listed as Perkinsiana minuta PP X 112 Sabellomma minuta Saccocirridae Saccocirrus species indet. X X M SS Asclerocheilus beringianus X X M SS Asclerocheilus mexicanus X X M SS Hyboscolex longiseta X M SS Hyboscolex quadricincta X M SS Scalibregmatidae X X X U P U P U P U P AM EN WD EN TABLE 1.1 (continued) Family Species Neolipobranchius blakei Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE X Pseudoscalibregma aciculata D1 D2 D3 113 X Scalibregma stenocerum X Sclerocheilus unoculus X D5 D6 X X Scalibregma inflatum D4 X X X X M F A D M SS UP EN M SS UP NW X X M SS UP WD X X M SS UP NW M SS UP EN S SU FI S SU FI WD S SU FI AM X Comments Serpulidae Apomatus species indet. X Circeis spirillum Crucigera websteri X Ficopomatus enigmaticus X Ficopomatus miamiensis X X ? ? ? X X X X ? ? ? ? ? ? S SU FI WD ? ? ? ? ? ? S SU FI AM X ? ? ? Senior synonym of Dexiospira spirillum Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Ficopomatus uschakovi X Filograna implexa X Filogranula species indet. X Hydroides bispinosus X Hydroides cruciger Hydroides dianthus Hydroides microtis SE X X X D2 D3 D4 D5 D6 M F A D S SU FI WD S SU FI WD S SU FI S SU FI WA S SU FI AM S SU FI WD X S SU FI WD X S SU FI WD X S SU FI NW X S SU FI EN S SU FI EN X X X X ? X X X X Hydroides mongeslopezi X Hydroides mucronatus X ? X X X D1 X X Hydroides diramphus Hydroides elegans SW X X ? ? ? ? Comments 114 TABLE 1.1 (continued) Includes records of junior synonym H. lunulifera TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Hydroides norvegica X 115 D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? S SU FI WD S SU FI WA S SU FI NW S SU FI WD X S SU FI WA X S SU FI SW S SU FI WD X X X X X X Hydroides sanctaecrucis Hydroides spongicola SE X Hydroides parvus Hydroides protulicola SW X X X Placostegus incomptus X Pomatostegus stellatus X X ? ? ? ? ? ? Protis species indet. X X S SU FI Protula species indet. X X S SU FI Pseudovermilia occidentalis X X Salmacina incrustans X X X X X S SU FI WD X X S SU FI WD Comments TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE Serpula vermicularis X Spiraserpula caribensis X D1 D2 D3 D4 D5 D6 X X M F A D S SU FI WD S SU FI SW Comments Listed as Pomatoceros Spirobranchus americanus X X X X X S SU FI NW americanus; depth rec. from Spirobranchus caeruleus X ? ? ? ? ? ? S SU FI WD Spirobranchus giganteus X ? ? ? ? ? ? S SU FI WD Spirobranchus incrassatus X ? ? ? ? ? ? S SU FI AM Spirobranchus kraussii X ? ? ? ? ? ? S SU FI WD Spirobranchus cf. minutus X ? ? ? ? ? ? S SU FI Spirobranchus tetraceros X ? ? ? ? ? ? S SU FI WD Spirorbis rupestris X ? ? ? ? ? ? S SU FI AT Listed as Pomatoceros caeruleus Senior synonym of S. pseudoincrassatus Senior synonym of Pomatoleios caerulescens Listed as Pomatoceros cf. minutus Senior synonym of S. dendropoma Senior synonym of Janua corrugatus 116 Uebelacker & Jones (1984) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 X X X X X X Escarpia laminata X X Lamellibrachia luymesi X Seepiophila jonesi X Vermiliopsis annulata D4 D5 D6 M F A D S SU FI NW S SY NP EN X S SY NP SW X S SY NP EN M CV AP NW M CV AP WD Siboglinidae X X X 117 Sigalionidae Dayipsammolyce ctenidophora X X X X Fimbriosthenelais hobbsi X X X M CV AP SW Fimbriosthenelais minor X X X M CV AP AT M CV AP AM Ehlersileanira incisa Leanira alba X X X X X X X X Comments Includes records of junior synonym V. bermudensis Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Leanira hystricis NE SW SE D1 D2 D3 X D4 D5 D6 X M F A D M CV AP AT Comments Pelogenia anoculata X X M CV AP AM Pelogenia arenosa X X M CV AP AT M OV AP WD Listed in Pisionidae M OV AP SW Listed in Pisionidae M OV AP WD Listed in Pisionidae M CV AP SW M CV AP WA M CV AP WD M CV AP WD M CV AP AM Pisione remota X Pisione wolfi Pisionidens indica X Psammolyce flava X Sigalion arenicola X Sigalion mathildae Sthenelais boa Sthenelais helenae X X X X ? X X ? ? X X ? ? ? X X X ? ? X X X X ? ? ? ? ? ? ? ? ? ? 118 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Sthenelais leidyi Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SE D1 X D2 119 M F A D M CV AP NW M CV AP AM X M CV AP X M CV AP M CV AP X Sthenolepis cf. grubei X X X Thalenessa cf. spinosa D3 X Sthenelanella uniformis Thalenessa cf. lewisii SW X X X D4 D5 D6 X X X X M SD UP EN X X M SD UP EN X X M SD UP EN X M SD UP AT X M SD UP EN Sphaerodoridae Clavodorum mexicanum Ephesiella bipapillata X Sphaerephesia fauchaldi Sphaerodoridium claparedii Sphaerodoridium lutzeni X X X X X X Comments Senior synonym of S. picta TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Sphaerodoropsis minutum SW SE X Sphaerodoropsis vittori D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M SD UP AT EN X X X X M SD UP X X X X D DS PP ? ? D DS PP AT X D DS PP WA X D DS PP AT S SU PP WD S SU PP S SU PP NW S SU PP WD Comments Spionidae X Aonidella dayi X Aonides mayaguezensis X Aonides paucibranchiata X Boccardia hamata X Boccardiella species indet. X ? X X X Carazziella hobsonae X Dipolydora caulleryi X X X X ? ? ? Listed as Minuspio cf. cirrobranchiata 120 Aonidella cf. cirrobranchiata Listed as Polydora caulleryi TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Dipolydora socialis X X Dispio uncinata X Laonice cirrata X Malacoceros indicus 121 Malacoceros vanderhorsti X SE D1 D2 D3 X X X X X X X X X X X X X X X X D4 D5 D6 M F A D S SU PP WD D DS PP WD D DS PP WD X D SD PP WD X D SD PP SW D DS PP AM D DS PP WD D DS PP SW X S SU PP S SU PP WD S SU PP AM X Microspio pigmentata Paraprionospio pinnata X Paraprionospio yokoyamai Polydora cf. aggregata X Polydora cornuta X Polydora plena X X X X X X X X X X X X X ? ? X ? ? ? ? Comments Depth record from Delgado-Blas (2004) Senior synonym of P. ligni Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Polydora websteri X X X Prionospio cirrifera X X X X Prionospio cristata X X X X X X Prionospio dayi SE D1 D2 D3 D4 D5 D6 X X M F A D S SU PP WD X X D DS PP WD X X D DS PP NW X X D DS PP AM Prionospio delta X ? ? ? ? ? ? D DS PP AM Prionospio dubia X ? ? ? ? ? ? D DS PP WD Prionospio ehlersi X ? ? ? ? ? ? D DS PP WD D DS PP AT D DS PP WD D DS PP AM D DS PP WD Prionospio fallax X Prionospio fauchaldi X X Prionospio heterobranchia X X Prionospio multibranchiata X X ? X ? X X ? ? ? ? Comments Listed as Minuspio cirrifera Listed as Apoprionospio dayi 122 TABLE 1.1 (continued) Listed as Minuspio multibranchiata TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Prionospio perkinsi NE SW X X SE D1 D2 X D3 D4 D5 D6 M F A D X D DS PP NW D DS PP AM D DS PP WD Prionospio pygmaeus X X X X Prionospio steenstrupi X X X X X ? ? ? ? ? ? S SU PP ? ? ? ? ? ? D DS PP WD D DS PP WD D DS PP NW D DS PP AT D DS PP WD Pseudopolydora species indet. 123 Pygospio elegans X X X Rhynchospio glutea X Scolecolepides viridis X X Scolelepis bonnieri X X Scolelepis squamata X X X Scolelepis texana X X X Spio pettiboneae X X X X ? ? X X X ? ? ? ? X X D DS PP WD X X D DS PP WA Comments Listed as Minuspio perkinsi Listed as Apoprionospio pygmaea Includes records of junior synonym S. agilis Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Spiophanes berkeleyorum NE SW X X Spiophanes bombyx X X X Spiophanes duplex X X X Spiophanes kroyeri SE X X X Spiophanes wigleyi X X X Streblospio benedicti X X X Streblospio gynobranchiata D1 ? X X D2 D3 M F A D X D DS PP AM X D DS PP WD D DS PP AM D DS PP WD D DS PP WD D DS PP WD D DS PP AT M SS UP WD M CV AP X X ? ? X X X X D4 ? D5 ? D6 ? Sternaspidae Sternaspis scutata X X X X X Syllidae Amblyosyllis species indet. X X Comments Includes records of junior synonym S. missionensis 124 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Branchiosyllis diazi SW SE X D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M CV AP EN X X M CV AP WD X X M CV AP WD 125 Branchiosyllis exilis X X Branchiosyllis oculata X X Brania gallagheri X X M CV AP NW Brania wellfleetensis X X M CV AP NW Dentatisyllis carolinae X X M CV AP NW Dentatisyllis uebelackerae X X M CV AP EN Dioplosyllis cf. octodentata X X M CV AP Eurysyllis tuberculata X M CV AP WD M CV AP WD M CV AP WD Eusyllis assimilis Eusyllis lamelligera X X X X X X D1 X ? ? ? X X ? ? ? Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Exogone arenosa Exogone atlantica NE Exogone lourei SE D1 X X X Exogone caribensis Exogone dispar SW X X OV AP AM M OV AP NW M OV AP SW M OV AP WD M OV AP AM M OV AP AT M OV AP SW X M OV AP WA X M OV AP WD M OV AP NW M CV AP ? ? ? X X D4 ? X X X X ? ? ? ? X X X X Geminosyllis species indet. M X X X D X Exogone meridionalis Exogone wolfi A X X X F X X Exogone verugera M X X Exogone rolani D3 D5 D6 X X Exogone pseudolourei D2 X X X ? ? ? ? Comments 126 TABLE 1.1 (continued) Senior synonym of E. parahomosetosa mediterranea TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Haplosyllis floridana Haplosyllis spongicola X Myrianida dentalia X X X X 127 Myrianida prolifer X X Odontosyllis enopla X X Odontosyllis cf. fulgurans X Odontosyllis luminosa X Odontosyllis cf. octodentata X SE D1 D2 D3 D4 D5 D6 M F A D X ? ? ? ? ? ? M CV AP WA X X X X M CV AP WA X X M CV AP WD Listed as Autolytus dentalius M CV AP WD Listed as Autolytus prolifer M CV AP WA X M CV AP X M CV AP M CV AP M CV AP SW X X X X X ? X ? ? X X ? ? ? SW Opisthodonta spinigera X X Opisthodonta uebelackerae X X ? ? ? ? ? ? M CV AP EN X ? ? ? ? ? ? M CV AP WD Opisthosyllis brunnea Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW Opisthosyllis longidentata Paraehlersia ferrugina NE SW SE D1 X X X D2 D3 M F A D M CV AP EN M CV AP WD X M CV AP EN X X X X D4 D5 D6 Parapionosyllis floridana X Parapionosyllis longicirrata X X X M CV AP WA Parapionosyllis uebelackerae X X X M CV AP EN M CV AP WD X M CV AP EN X M CV AP WA M CV AP WD Parasphaerosyllis indica X X X Pionosyllis aciculigrossa X X Pionosyllis gesae X X X X X Pionosyllis spinisetosa Pionosyllis weismanni X X Plakosyllis brevipes X X X X X M CV AP WD X X M CV AP AT Comments Listed as Syllis ferrugina 128 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Proceraea cornuta X X Prosphaerosyllis longicauda X Pseudosyllides curacaoensis SE D1 D2 ? X X ? ? X 129 Salvatoria clavata X X X Salvatoria swedmarki X X X Sphaerosyllis aciculata X Sphaerosyllis bilobata X X ? ? ? X X X X X Sphaerosyllis glandulata Sphaerosyllis magnidentata Sphaerosyllis piriferopsis X X X X D4 D5 D6 X X Salvatoria vieitezi D3 X X X ? ? ? ? ? ? M F A D Comments M CV AP AT M OV AP AT M CV AP SW M OV AP WD Listed as Brania clavata M OV AP AT Listed as Brania swedmarki M OV AP AT Listed as Grubeosyllis vieitezi M OV AP NW M OV AP WA M OV AP AT M OV AP AT M OV AP AT Listed as Sphaerosyllis longicauda Family Species Sphaerosyllis renaudae Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 X D2 D3 D4 D5 D6 X Sphaerosyllis riseri X X X D M OV AP NW M OV AP WD M OV AP AT Streptospinigera heteroseta X X M CV AP EN Streptosyllis websteri X X M CV AP AT Syllides bansei X X M CV AP WD Syllides floridanus X X M CV AP WA Syllides fulvus X X X M CV AP WD Syllis aciculata X ? ? ? ? ? ? M CV AP AM ? ? ? ? ? ? M CV AP AT M CV AP WD Syllis alternata X X X X X A X X X F Sphaerosyllis taylori Syllis alosae X X M Comments Senior synonym of S. pettiboneae 130 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Syllis amica X Syllis annularis X Syllis armillaris X SW SE D1 D2 D3 D4 D5 D6 X ? X ? ? X X ? ? ? M F A D M CV AP AT M CV AP NW M CV AP WD 131 Syllis beneliahuae X ? ? ? ? ? ? M CV AP WD Syllis broomensis X ? ? ? ? ? ? M CV AP WD Comments Includes records of junior Syllis corallicola X X X X ? ? ? ? ? ? M CV AP WD synonyms S. corallicoides and S. tigrinoides Syllis cornuta X X Syllis garciai X Syllis gerlachi Syllis gracilis X ? X X X X X ? ? X X X X X X ? ? ? M CV AP WD M CV AP AT M CV AP WD M CV AP WD Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Syllis hyalina SW SE X Syllis cf. lutea D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M CV AP WD X X M CV AP X Syllis maryae X ? ? ? ? ? ? M CV AP WA Syllis mexicana X ? ? ? ? ? ? M CV AP SW M CV AP SW Syllis ortizi X X X Syllis papillosus X X X X M CV AP EN X X M CV AP WD M CV AP WD M CV AP AT M CV AP WA M CV AP SW Syllis prolifera X Syllis variegata X Trypanosyllis coeliaca X Trypanosyllis parvidentata X Trypanosyllis vittigera X X X X X X X X X X Comments 132 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Trypanosyllis zebra SW SE X Xenosyllis cf. scabra D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? M CV AP WD X X M CV AP X X D SD TE WD X D SD TE NW X S SD TE WD X S SD TE X D SD TE X S SD TE S DS TE WD S SD TE AM X Terebellidae Amaeana trilobata X X 133 Enoplobranchus sanguineus X Eupolymnia nebulosa X Euthelepus species indet. X X X Hauchiella species indet. X Lanassa species indet. Lanice conchilega Lanicides taboguillae X X X X X ? X X ? ? ? ? ? Comments Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW Loimia medusa X X X Loimia viridis X X X SE D1 X D2 D3 X D4 D5 D6 M F A D X S SD TE WD X X S SD TE NW X D SD TE Lysilla species indet. X X Neoamphitrite edwardsi X X S SD TE Neoleprea species indet. X X S SD TE Pista cristata X X Pista fasciata X Pista palmata X X HA X X S SD TE WD X X X S SD TE WD X X S SD TE WA S SD TE EN S SD TE WD D SD TE Pista papillosa X X X Pista quadrilobata X X X Polycirrus cf. albicans X X X Comments 134 TABLE 1.1 (continued) TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE Polycirrus carolinensis SW SE X D1 D2 D3 D4 D5 D6 M F A D ? ? ? ? ? ? D SD TE NW 135 Polycirrus cf. denticulatus X X D SD TE Polycirrus eximius dubius X X D SD TE Polycirrus cf. haematodes X X D SD TE Polycirrus plumosus X X D SD TE Rhinothelepus species indet. X X S SD TE Streblosoma hartmanae X X S SD TE Telothelepus cf. capensis X X S SD TE Terebella lapidaria X X S SD TE WD Terebella verrilli X X S SD TE WA Thelepus setosus X X S SD TE WD X X ? ? ? ? ? ? X X ? ? ? ? ? ? Comments WA WD WA Includes records of junior synonym Streblosoma verrilli TABLE 1.1 (continued) Family Species Presence data of the Presence data of the six Polychaete four GoM sectors bathymetric ranges properties NW NE SW SE D1 D2 D3 D4 D5 D6 M F A D S SD TE SW Comments Terebellides carmenensis X X Terebellides distincta X ? ? ? ? ? ? S SD TE NW Terebellides lanai X ? ? ? ? ? ? S SD TE SW Terebellides parvus X ? ? ? ? ? ? S SD TE SW X X X S SD TE WD X X X S SD TE WD X D DS PP Terebellides stroemi X Trichobranchus glacialis Trochochaetidae Trochochaeta species indet. X X 136 Trichobranchidae References Appeltans, W., Ahyong, S.T., Anderson, G., Angel, M.V., Artois, T., Bailly, N., Bamber, R., Barber, A., Bartsch, I., Berta, A., Błażewicz-Paszkowycz, M., Bock, P., Boxshall, G., Boyko, C.B., Brandão, S.N., Bray, R.A., Bruce, N.L., Cairns, S.D., Chan, T.Y., Cheng, L., Collins, A.G., Cribb, T., Curini-Galletti, M., Dahdouh-Guebas, F., Davie, P.J., Dawson, M.N., De Clerck, O., Decock, W., De Grave, S., de Voogd, N.J., Domning, D.P., Emig, C.C., Erséus, C., Eschmeyer, W., Fauchald, K., Fautin, D.G., Feist, S.W., Fransen, C.H., Furuya, H.,Garcia-Alvarez, O., Gerken, S., Gibson, D., Gittenberger, A., Gofas, S., Gómez-Daglio, L., Gordon, D.P., Guiry, M.D., Hernandez, F., Hoeksema, B.W., Hopcroft, R.R., Jaume, D., Kirk, P., Koedam, N., Koenemann, S., Kolb, J.B., Kristensen, R.M., Kroh, A., Lambert, G., Lazarus, D.B., Lemaitre, R., Longshaw, M., Lowry, J., Macpherson, E., Madin, L.P., Mah, C., Mapstone, G., McLaughlin, P.A., Mees, J., Meland, K., Messing, C.G., Mills, C.E., Molodtsova, T.N., Mooi, R., Neuhaus, B., Ng, P.K., Nielsen, C., Norenburg, J., Opresko, D.M., Osawa, M., Paulay, G., Perrin, W., Pilger, J.F., Poore, G.C., Pugh, P., Read, G.B., Reimer, J.D., Rius, M., Rocha, R.M., Saiz-Salinas, J.I., Scarabino, V., Schierwater, B., Schmidt-Rhaesa, A., Schnabel, K.E., Schotte, M., Schuchert, P., Schwabe, E., Segers, H., Self-Sullivan, C., Shenkar, N., Siegel, V., Sterrer, W., Stöhr, S., Swalla, B., Tasker, M.L.,Thuesen, E.V., Timm, T., Todaro, M.A., Turon, X., Tyler, S., Uetz, P., van der Land, J., Vanhoorne, B., van Ofwegen, L.P., van Soest, R.W., Vanaverbeke, J., Walker-Smith, G., Walter, T.C., Warren, A., Williams, G.C., Wilson, S.P. & Costello, M.J. (2012a) The magnitude of global marine species diversity. Current Biology, 22, 2189-2202. 137 Appeltans, W., Bouchet, P., Boxshall, G.A., De Broyer, C., de Voogd, N.J., Gordon, D.P., Hoeksema, B.W., Horton, T., Kennedy, M., Mees, J., Poore, G.C.B., Read, G., Stöhr, S., Walter, T.C. & Costello, M.J. (Eds.) (2012b). World Register of Marine Species. Available from http://www.marinespecies.org (accessed on 15 January 2013) Baco, A.R., Rowden, A.A., Levin, L.A., Smith, C.R. & Bowden, D.A. (2010) Initial characterization of cold seep faunal communities on the New Zealand Hikurangi margin. Marine Geology, 272(1-4), 251-259. Baco, A.R. & Smith, C.R. (2003) High species richness in deep-sea chemoautotrophic whale skeleton communities. Marine Ecology Progress Series, 260, 109-114. Barroso, R., Klautau, M., Solé-Cava, A.M. & Paiva, P.C. (2010) Eurythoe complanata (Polychaeta: Amphinomidae), the ‘cosmopolitan’ fireworm, consists of at least three cryptic species. Marine Biology, 157(1), 69-80. Beesley, P.L, Ross, G.J.B. & Glasby, C.J. (Eds.) (2000) Polychaetes & Allies: The Southern Synthesis. Fauna of Australia. Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. CSIRO Publishing, Melbourne, xii 465 pp. Blake, J.A. (1993) New genera and species of deep-sea polychaetes of the family Nautiliniellidae from the Gulf of Mexico and the eastern Pacific. Proceedings of the Biological Society of Washington, 106(1), 147-157. Böggemann, M. & Fiege, D. (2001) Description of seven new species of the genus Glycera Savigny, 1818 (Annelida: Polychaeta: Glyceridae). Ophelia, 54(1), 29-49. Castelli, A., Bianchi, C.N., Cantone, G., Çinar, M.E., Gambi, M.C., Giangrande, A., Iraci Sareri, D., Lanera, P., Licciano, M., Musco, L., Sanfilippo, R. & Simonini, R. (2008) Annelida Polychaeta Biologia Marina Mediterranea, 15(suppl.), 323-373. 138 Clarke, K.R. & Gorley, R.N. (2006) PRIMER v6: User Manual/Tutorial. PRIMER-E, Plymouth, 190 pp. Coates, A.G. & Obando, J.A. (1996) The geological evolution of the Central American isthmus. In: Jackson, J.B.C., Budd, E.F. & Coates, A.G. (Eds.) Evolution and environment in tropical America. The University of Chicago Press, Chicago, pp. 21-56. Conway Morris, S. & Peel, J.S. (2008) The earliest annelids: Lower Cambrian polychaetes from the Sirius Passet Lagerstätte, Peary Land, North Greenland. Acta Palaeontologica Polonica, 53(1), 137-148. Dauer, D.M., Maybury, C.A. & Ewing, R.M. (1981) Feeding behavior and general ecology of several spionid polychaetes from the Chesapeake Bay. Journal of Experimental Marine Biology and Ecology, 54, 21-38. Dauvin, J.C., Bachelet, G. & Bellan, G. (2006) Biodiversity and biogeographic relationships of the polychaete fauna in French Atlantic and Mediterranean waters. Scientia Marina, 70S3, 259-267. de León González, J.A. & Solís-Weiss, V. (1997) A new species of Stenoninereis (Polychaeta: Nereididae) from the Gulf of Mexico. Proceedings of the Biological Society of Washington, 110(2), 198-202. de León González, J.A. & Solís-Weiss, V. (1998) The genus Perinereis (Polychaeta: Nereididae) from Mexican littoral waters, including the description of three new species and the redescriptions of P. anderssoni and P. elenacasoae. Proceedings of the Biological Society of Washington, 111(3), 674-693. 139 de León González, J.A., Solís-Weiss, V. & Valadez-Rocha, V. (2001) Two new species of Platynereis (Polychaeta: Nereididae) from eastern Mexican shores. Proceedings of the Biological Society of Washington, 114(2), 389-395. Delgado-Blas, V.H. (2004) Two new species of Paraprionospio (Polychaeta: Spionidae) from the Grand Caribbean region and comments of the genus status. Hydrobiologia, 520(1-3), 189–198. Desbruyères, D., Segonzac, M. & Bright, M. (2006) Handbook of deep-sea hydrothermal vent fauna. Denisia, 18, 1–544. Fauchald, K. (1982) Revision of Onuphis, Nothria, and Paradiopatra (Polychaeta: Onuphidae) based upon type material. Smithsonian Contributions to Zoology, 356, 109 pp. Fauchald, K. (1984) Polychaete distribution patterns, or: can animals with Palaeozoic cousins show largescale geographical patterns. In: Hutchings, P.A. (Ed.) Proceedings of the first international polychaete conference. The Linnean Society of New South Wales, Sydney, Australia., pp. 1-6. Fauchald, K. (1992) A review of the genus Eunice (Polychaeta: Eunicidae) based upon type material. Smithsonian Contributions to Zoology, 523, 1-422. Fauchald, K., Granados-Barba, A. & Solís-Weiss, V. (2009) Polychaeta (Annelida) of the Gulf of Mexico. In: Felder, D.L. & Camp, D.K. (Eds.) Gulf of Mexico origin, waters, and biota: Volume I, Biodiversity. Texas A&M University Press, College Station, pp. 751-788. Fauchald, K. & Jumars, P.A. (1979) The diet of worms: a study of polychaete feeding guilds. Oceanography and Marine Biology – An Annual Review, 17, 193-284. 140 Felder, D.L. & Camp, D.K. (2009) Gulf of Mexico origin, waters, and biota: Volume I, Biodiversity. Texas A&M University Press, College Station, 1393 pp. Fiege, D., Ramey, P.A. & Ebbe, B. (2010) Diversity and distributional patterns of Polychaeta in the deep South Atlantic. Deep-Sea Research I, 57(10), 1329-1344. Fitzhugh, K. (1990) Fabricinuda, a new genus of Fabriciinae (Polychaeta: Sabellidae). Proceedings of the Biological Society of Washington, 103(1), 161-178. Galtsoff, P.S. (Ed.) (1954) Gulf of Mexico, Its Origin, Waters and Marine Life. Fishery Bulletin 89. Fishery Bulletion of the Fish and Wildlife Service, Volume 55. United States Government Printing Office, Washington, D.C., xiv 604 pp. Gaston, G.R., McLelland, J.A. & Heard, R.W. (1992) Feeding biology, distribution, and ecology of two species of benthic polychaetes: Paraonis fulgens and Paraonis pygoenigmatica (Polychaeta: Paraonidae). Gulf Research Reports, 8(4), 395-399. Glasby, C.J. & Alvarez, B. (1999) Distribution patterns and biogeographic analysis of Austral Polychaeta (Annelida). Journal of Biogeography, 26(3), 507-533. Glasby, C.J. & Watson, C. (2001) A new genus and species of Syllidae (Annelida: Polychaeta) commensal with octocorals. The Beagle, Records of the Museum and Art Galleries of the Northern Territory, 17, 43–51. Glover, A., Paterson, G., Bett, B., Gage, J., Sibuet, M., Sheader, M. & Hawkins, L. (2001) Patterns in polychaete abundance and diversity from the Madeira Abyssal Plain, northeast Atlantic. Deep-Sea Research I, 48(1), 217-236. Grassle, J. & Grassle, J.F. (1976) Sibling species in the marine pollution indicator Capitella (Polychaeta). Science, 192(4239), 567-569. 141 Guillou, M. & Hily, C. (1983) Dynamics and biological cycle of a Melinna palmata (Ampharetidae) population during the recolonisation of a dredged area in the vicinity of the harbour of Brest (France). Marine Biology, 73(1), 43-50. Hartman, O. (1951) The littoral marine annelids of the Gulf of Mexico. Publications of the Institute of Marine Science, 2(1), 7-124. Hartman, O. (1954) Polychaetous annelids of the Gulf of Mexico. In: Galtsoff, P.S. (Ed.) Gulf of Mexico, Its Origin, Waters and Marine Life. Fishery Bulletin 89. Fishery Bulletion of the Fish and Wildlife Service, Volume 55. United States Government Printing Office, Washington, D.C., pp. 413-417. Hedgpeth, J.W. (1953) An introduction to the zoogeography of the northwestern Gulf of Mexico with reference to the invertebrate fauna. Publications of the Institute of Marine Science, 3(1), 107-224. Imajima, M., Reuscher, M.G. & Fiege, D. (2013) Ampharetidae (Annelida: Polychaeta) from Japan. Part II: Genera with elevated and modified notopodia. Zootaxa, 3647(1), 137-166. Knight-Jones, P. & Perkins, T.H. (1998) A revision of Sabella, Bispira and Stylomma (Polychaeta: Sabellidae). Zoological Journal of the Linnean Society, 123(4), 385-467. Knox, G.A. (1957) The distribution of polychaetes in the Indo-Pacific. Proceedings of the 8th Pacific Science Congress, 3, 403-411. Kruse, I., Strasser, M. & Thiermann, F. (2004) The role of ecological divergence in speciation between intertidal and subtidal Scoloplos armiger (Polychaeta, Orbiniidae). Journal of Sea Research, 51(1), 53-62. Mareano (2013) Mareano. Samler kunnskap om havet. Available from http://www.mareano.no/bilder/videoer (accessed 12 February 2013). 142 Martin, D., Marin, I. & Britayev, T.A. (2008) Features of the first known association between Syllidae (Annelida, Polychaeta) and crustaceans. Organisms, Diversity & Evolution, 8, 279-281. Mayr, E. & Ashlock, P.D. (1991) Principles of animal systematics. McGraw-Hill, New York, xx 475 pp. Montiel San Martín, A., Gerdes, D. & Arntz, W.E. (2005) Distributional patterns of shallowwater polychaetes in the Magellan region: a zoogeographical and ecological synopsis. Scientia Marina, 69(S2), 123-133. Moretzsohn, F., Brenner, J., Michaud, P., Tunnell, J.W. & Shirley, T. (2011) Biodiversity of the Gulf of Mexico Database (BioGoMx). Version 1.0. Harte Research Institute for Gulf of Mexico Studies (HRI), Texas A&M University-Corpus Christi (TAMUCC), Corpus Christi, Texas. Available from: http://www.gulfbase.org/biogomx/biosearch.php (accessed 26 July 2011). OBIS (2013) Ocean Biogeographic Information System. Available from http://www.iobis.org/ (accessed 25 January 2013). Paterson, G.L.J., Glover, A.G., Barrio Froján, C.R.S., Whitaker, A., Budaeva, N., Chimonides, J. & Doner, S. (2009) A census of abyssal polychaetes. Deep-Sea Research II, 56(19-20), 1739-1746. Pawlik, J.R. (1983) A sponge-eating worm from Bermuda: Branchiosyllis oculata (Polychaeta, Syllidae). Marine Ecology, 4(1), 65-79. Pettibone, M.H. (1953) Some scale-bearing polychaetes of Puget Sound and adjacent waters. University of Washington Press, Seattle, 89 pp. 143 Pettibone, M.H. (1984) A new scale-worm commensal with deep-sea mussels on the Galapagos hydrothermal vent (Polychaeta: Polynoidae). Proceedings of the Biological Society of Washington, 97(1), 226-239. Pleijel, F., Rouse, G.W., Sundkvist, T. & Nygren, A. (2012) A partial revision of Gyptis (Gyptini, Ophiodrominae, Hesionidae, Aciculata, Annelida), with descriptions of a new tribe, a new genus and five new species. Zoological Journal of the Linnean Society, 165(3), 471–494. Reish, D.J. (1957) The relationship of the polychaetous annelid Capitella capitata (Fabricius), to waste discharges of biological origin. In: Tarzwell, C.M. (Ed.) Biological problems in water pollution. United States Public Health Services, Washington, D.C., pp. 195-200. Rubinoff, I. (1968) Central American sea-level canal: possible biological effects. Science, 161(3844), 857-861. San Martín, G. (1990) Eusyllinae (Syllidae, Polychaeta) from Cuba and Gulf of Mexico. Bulletin of Marine Science, 46(3), 560-619. San Martín, G. (1991a) Syllinae (Polychaeta: Syllidae) from Cuba and the Gulf of Mexico. Bulletin of Marine Science, 48(2), 227-235. San Martín, G. (1991b) Grubeosyllis and Exogone (Exogoninae, Syllidae, Polychaeta) from Cuba, the Gulf of Mexico, Florida and Puerto Rico, with a revision of Exogone. Bulletin of Marine Science, 49(3), 715-740. San Martín, G. (1992) Syllis Savigny in Lamarck, 1818 (Polychaeta: Syllidae: Syllinae) from Cuba, the Gulf of Mexico, Florida and North Carolina, with a revision of several species described by Verrill. Bulletin of Marine Science, 51(2), 167-196. 144 Schüller, M & Ebbe, B. (2007) Global distributional patterns of selected deep-sea Polychaeta (Annelida) from the Southern Ocean. Deep-Sea Research II, 54(16-17), 1737-1751. Schüller, M., Ebbe, B. & Wägele, J.-W. (2009) Community structure and diversity of polychaetes (Annelida) in the deep Weddell Sea (Southern Ocean) and adjacent basins. Marine Biodiversity, 39(2), 95-108. Schulze, S.R., Rice, S.A., Simon, J.L. & Karl, S.A. (2000) Evolution of poecilogony and the biogeography of North American populations of the polychaete Streblospio. Evolution, 54(4), 1247-1259. Sørensen, T. (1948) A method of establishing groups of equal amplitude in plant sociology based on similarity of species and its application to analyses of the vegetation on Danish commons. Danske Videnskabernes Selskabs Biologiske Skrifter, 5, 1-34. Spivey, H.R. (1981) Origins, distribution, and zoogeographic affinities of the Cirripedia (Crustacea) of the Gulf of Mexico. Journal of Biogeography, 8(2), 153-176. Struck, T.H., Paul, C., Hill, N., Hartmann, S., Hösel, C., Kube, M., Lieb, B., Meyer, A., Tiedemann, R., Purschke, G. & Bleidorn, C. (2011) Phylogenomic analyses unravel annelid evolution. Nature, 471(7336), 95-98. Uebelacker, J.M. & Johnson, P.G. (Eds.) (1984) Taxonomic guide to the polychaetes of the northern Gulf of Mexico. Final Report to the Minerals Management Service, contract 1412-001-29091. Barry A. Vittor & Associates, Inc., Mobile, Alabama, 7 volumes. Wehe, T. (2006) Revision of the scale worms (Polychaeta: Aphroditoidea) occurring in the seas surrounding the Arabian Peninsula. Part I: Polynoidae. Fauna of Arabia, 22, 23-197. Wehe, T. (2007) Revision of the scale worms (Polychaeta: Aphroditoidea) occurring in the seas surrounding the Arabian Peninsula. Part II: Sigalionidae. Fauna of Arabia, 23, 41-124. 145 Wehe, T. & Fiege, D. (2002) Annotated checklist of the polychaete species of the seas surrounding the Arabian Peninsula: Red Sea, Gulf of Aden, Arabian Sea, Gulf of Oman, Arabian Gulf. Fauna of Arabia, 19, 7-238. Wicksten, M.K. & Packard, J.M. (2005) A qualitative zoogeographic analysis of decapod crustaceans of the continental slopes and abyssal plain of the Gulf of Mexico. Deep-Sea Research I, 52, 1745-1765. Zrzavý, J., Říha1, P., Piálek, L. & Janouškovec1, J. (2009) Phylogeny of Annelida (Lophotrochozoa): total-evidence analysis of morphology and six genes. BMC Evolutionary Biology, 9, 189 (14 pp). 146 CHAPTER II Spatial and Temporal Dynamics of Polychaete Assemblages on the Northern Gulf of Mexico Continental Slope Abstract Polychaete abundance and diversity along three transects of the northern Gulf of Mexico continental slope were examined. The transects were located at the eastern slope, the central slope, and the Mississippi Trough and included stations that were sampled twice or multiple times. Spatial, seasonal, short-, and long-term comparisons of polychaete assemblages were conducted at the central slope, while only spatial and annual dynamics could be examined at the eastern slope and the Mississippi Trough. Abundance was not correlated to depth between 350 and 1500 m at the central and eastern slope, but sharply declined between 1500 and 2100 m. At the Mississippi Trough polychaete abundance was higher at depths between 500 and 1500 m, even though it started declining between 700 and 900 m. Compared to fall samples, spring abundance approximately doubled at the central slope at 350-1500 m, but was only slightly higher at 2100 m. This increase may have been caused by spawning events in spring when nutrient influx of the Mississippi Atchafalaya River system peaked. Differences in abundance between stations at the same depth on the eastern transect indicate that sediment composition and localized oceanographic processes may also shape the assemblages. For measuring changes of polychaete diversity over space and time, the Morisita-Horn index proved to be useful at handling unequal sample sizes. Polychaete assemblages of all transects changed with increasing depth. Temporal changes of the assemblages were generally slight. At the central transect I 147 observed short-term changes (~ 1 year) that had reversed in the long run (~ 16 years). This pattern may be caused by periodical disturbance events and species-species interactions. The pronounced compositional change at a single station at the central slope was most likely caused by a hydrocarbon seep in the vicinity, rather than by a substantial change of the polychaete fauna over time. Key words: community ecology, benthos, β-diversity, temporal change, Morisita-Horn index, distribution, abundance Introduction The premise that benthic communities in the deep-sea are stable over time has been challenged by a number of contradictory findings (Billett et al. 2001, Galéron et al. 2009). Seasonal events such as algae blooms, long-term cycles such as the El Niño Southern Oscillation (ENSO), and stochastic events affect benthic communities not only in shallow water but in bathyal and abyssal depths as well (Aller 1997, Drazen et al. 1998, Levin et al. 2002). To date only a few deep-sea locations have been resampled over time scales of years or decades (for a list see Glover et al. 2010). Resources for technically demanding and expensive deep-sea sampling are usually allocated to unexplored parts of the world’s oceans. However, in order to understand temporal dynamics of the deep sea benthos it is crucial to resample the same locations. In this study I examined the spatial and temporal dynamics of the polychaete diversity and abundance at the northern Gulf of Mexico continental slope. Polychaetes are among the most 148 prominent benthic organisms. On the northern Gulf of Mexico continental slope they account for 37.5% of macrofaunal specimens (Rowe & Kennicutt 2009). The different polychaete families have a wide variety of morphology, mobility, and diets (Fauchald & Jumars 1979). These diverse adaptations make them an interesting indicator group because environmental variables affect the various families in different ways. Furthermore, there is some evidence that polychaetes may be a viable surrogate for benthic macrofauna diversity measurements (Olsgard et al. 2003). Oil and gas exploration and exploitation at the northern Gulf of Mexico continental margin prompted several sampling programs to create baseline data of benthic assemblages and to study potential impacts (Pequegnat 1983). Two of the most extensive surveys were the “Northern Gulf of Mexico Continental Slope Study” (NGoMCS) in the years 1983-1985 (Gallaway 1988) and the “Deep Gulf of Mexico Benthos Study” (DGoMB) in the years 2000-2002 (Rowe & Kennicutt 2009), both initiated by the Minerals Management Service (now Bureau of Ocean Energy Management, Research and Enforcement). Among the numerous areas sampled during the NGoMCS and DGoMB surveys, I focused on three regions that contained sampling stations that were repeatedly sampled. In the eastern Gulf of Mexico and the Mississippi Trough several stations were resampled within the NGoMCS and the DGoMB projects, respectively. These data sets enabled us to compare the temporal dynamics of the polychaete assemblages over a short period of time (~1-2 years). The largest data set was available from a central transect where some of the stations were sampled multiple times during the NGoMCS survey, and resampled during the DGoMB survey (Appendix), allowing for examination of seasonal, short- (~1-2 years) and long-term (~16-17 years) dynamics of the polychaete communities. 149 Materials & Methods Samples were collected during four cruises of the Northern Gulf of Mexico Continental Slope Study (NGoMCS) between 1983 and 1985 (Gallaway 1988) and three cruises of the Deep Gulf of Mexico Benthos Study (DGoMB) between 2000 and 2002 (Rowe & Kennicutt 2009) (station list in Appendix). In the ordination plots the sampling period (NGoMCS and DGoMB cruises during which the sample was retrieved) of each station is indicated by abbreviations: N1=November 1983, N2=April 1984, N3=November 1984, N4=May 1985, D1=May/June 2000, D2=June 2001, D3=August 2002. Three regions in the northern Gulf of Mexico were examined: the eastern continental slope, the central continental slope, and the Mississippi Trough (Fig. 2.1). Sampling stations were arranged along transects that were approximately perpendicular to bathymetric isopleths. Transects are referred to as C (central transect), E (eastern transect), and MT (Mississippi Trough). Stations of the same transects are distinguished by numbers, increasing from shallow to deep. At the central continental slope, the original transect, consisting of stations C1-C5, was complemented by additional stations C6 to C12 during the November 1984 cruise (Fig. 2.2). At the eastern transect stations E1, E2, and E3 were complemented by several stations of the same depths during the second sampling period in May 1985. Stations of the same depths share the same number but are distinguished by an additional lower case letter, e.g., E2a and E2b (Fig. 2.3). The maps showing the sampling sites were generated with ArcMap. All samples were collected with box corers, with a sample size of 0.0569 m2 during the first NGoMCS cruise, 0.0475 m2 during the remaining NGoMCS cruises, and 0.1725 m2 during the DGoMB cruises. Between three and six replicates per station were retrieved during the NGoMCS cruises. While five replicates were retrieved at most DGoMB sampling stations, I included only three replicates in the analyses. This is because the box corer used for the DGoMB 150 151 FIGURE 2.1 Map of the Gulf of Mexico showing the locations of thee three transects from which samples were analyzed. 152 FIGURE 2.2 Detailed map of the station locations of the central transect and the Mississippi Trough. 153 FIGURE 2.3 Detailed map of the station locations of the eastern transect. study was larger than the ones used during the NGoMCS survey. The inclusion of three replicates was a compromise to sufficiently account for the patchiness of benthic assemblages, but not to inflate the sample size of the DGoMB samples too much above NGoMCS level. Complete lists of the polychaetes of all replicates of NGoMCS were obtained from the appendices of Hubbard (1995). A partial list of polychaetes of DGoMB was obtained from Wang (unpublished data of Wang 2004). Polychaetes of unsorted DGoMB replicates were identified to family level. Species identifications of the available data sets were lumped into families. The main reason for this decision was that nearly half of the specimens could not be identified to species level. The obstacles to species identification were poor condition and fragmentation of many specimens and the poorly resolved taxonomy of some taxa. Excluding nearly half of the specimens would have caused extensive loss of information. Therefore, using family level identification as a taxonomic surrogate may be more advantageous when a large portion is not identifiable to species level (Reuscher in prep.). Furthermore, family level data of benthic macrofauna will detect the same basic spatial patterns as those developed at the species level, and often with less noise by eliminating the influence of rare species (Warwick 1988, Montagna & Harper 1996). These advantages outweighed concerns about the subjectivity of taxonomic classifications (Bertrand et al. 2006). The taxonomic classification used in this study was that of Beesley et al. (2000). For measurements of polychaete abundance, I converted the polychaete specimen counts to number of individuals per square meter (ind. m-2) to account for unequal sample sizes. Average abundance and standard error were computed in Microsoft Excel. Bar graphs were produced with Microsoft Excel. One way ANOVAs were performed to test for significant 154 differences in polychaete abundances at between different sampling periods at the same sampling stations. For measuring the spatial and temporal turnover of polychaete assemblages, also known as β-diversity, replicates of each station were pooled. Stations with less than 100 polychaete specimens were excluded because the statistical error is too large for such a small sample size (Wolda 1981). Counts of each polychaete family were square-root transformed. The MorisitaHorn index (Horn 1969) was used to measure β-diversity. This index outperforms other indices when samples of unequal sizes are compared (Wolda 1981). Calculations of β-diversity values were performed in Microsoft Excel. Ordination of the similarity matrix by means of non-metric multidimensional scaling (MDS) was performed with Primer 6 (Clarke & Gorley 2006). The same program was used to perform “analyses of similarity” (ANOSIM) to test for significant differences among different sampling periods. “Similarity percentage” (SIMPER) was performed to measure the contributions of different polychaete families to the dissimilarity among samples of different sampling periods. For the ANOSIM procedure I used the Bray-Curtis similarity index when sample size of compared replicates and stations was equal and the Morisita-Horn index when sample size was unequal. For the SIMPER procedure I converted the abundance of each family of the compared samples to ind. m-2 to account for unequal sample sizes. Results A) Abundance In November of 1983 and 1984 polychaete abundance at the upper slope stations of the central transect, including C1-C4, C6, C8, and C9, was roughly between 1000-2000 ind. m-2 (Fig. 2.4). 155 156 FIGURE 2.4 Polychaete abundance of different stations and sampling periods at the central transect. Error bars indicate the standard error. Stations are arranged according to increasing depth from left to right. Sampling periods are indicated by different colors (see legend). No consistent decrease of abundance with depth was observed among these sampling sites that were between 350 and 1500 m deep. Station C7 was exceptional for its unusually high abundance (2639±594 ind. m-2). There was a sharp decline of abundance between the upper and the lower slope stations, including C-11 (2100 m), C-5 (2400-2500 m), and C-12 (about 2900 m). These stations had average densities of only 265-627 ind. m-2 in the November samples. In April 1984 polychaete numbers of the upper slope stations had approximately doubled. The increase between November 1983 and April 1984 was highly significant at the upper slope stations C1-C4 (Table 2.1). The decrease in the abundance between the sampling periods of April and November 1984 was also highly significant at the upper slope stations, except for station C4 where the decrease was not significant (Table 2.1). In the spring samples abundance did not significantly decrease with depth at the upper slope stations C1-C4. However, a steep decline occurred between the upper slope stations and C5, the only lower slope station sampled at the time (Fig. 2.4). Polychaete abundance at station C5 was moderately increased to 832±107 ind. m-2 in April 1984. Abundance at station C5 was significantly different between April 1984 and November 1984, but neither sample differed significantly from the one of November 1983 (Table 2.1). None of the stations at the central transect had significantly different abundances between samples of November 1983 and November 1984. Polychaete abundance in the DGoMB samples of late May and June 2000 and 2001 was generally similar to the fall samples of NGoMCS. Station C7 did not have conspicuously high abundance as it did during in November 1984, but instead was similar to the other upper slope stations C1 and C4. Abundances at C1, C4, and C12 were not significantly different between the DGoMB samples and the November samples of NGoMCS (Table 2.1). Compared to the 157 TABLE 2.1 p-values of ANOVAs on polychaete abundance at C transect stations of different sampling periods. n.s. = p-value not significant. C1 C2 C3 C7 C4 C5 Nov 83 vs. Apr 84 p<0.005 p<5x10-4 p<0.005 p<1x10-5 n.s. Nov 83 vs. Nov 84 n.s. n.s. n.s. n.s. n.s. Apr 84 vs. Nov 84 p<0.01 p<1x10-4 p<0.005 n.s. p<0.05 Nov 83 vs. May 00 n.s. n.s. Apr 84 vs. May 00 n.s. p<5x10-4 Nov 84 vs. May 00 n.s. n.s. Nov 84 vs. Jun 01 n.s. Nov 84 vs. May 00 + Jun 01 p<0.05 May 00 vs. Jun 01 n.s. n.s. C12 n.s. NGoMCS spring samples, abundance at C4 was significantly lower, while at C1 the difference was not significant. At station C7 no significant differences were found between the samples of 1984, 2000, and 2001. However, because of the low number of DGoMB replicates analyzed, I pooled the samples of 2000 and 2001. The pooled DGoMB samples of station C7 had a significantly lower abundance, than the NGoMCS sample (Table 2.1). At the eastern transect samples were collected in April 1984 and May 1985. Abundances at stations E1, E2, and E3 were similar to the spring samples of the central transect (Fig. 2.5). Abundance at E4 was lower (1379±189 ind. m-2), than that of C4 or any of the other upper slope 158 159 FIGURE 2.5 Polychaete abundance of different stations and sampling periods at the eastern transect. Error bars indicate the standard error. Stations are arranged according to increasing depth from left to right. Stations with same numbers are at the same depth and are arranged from northwest to southeast from left to right. Sampling periods are indicated by different colors (see legend). stations. However, the most conspicuous depth-related decrease of abundance was between stations E4 (1350 m) and E5 (2800-2900 m), where approximately 500 ind. m-2 were present. Difference in polychaete abundance between the samples of 1984 and 1985 were not significant at stations E1, E2, and E5. At E2 polychaete numbers increased from 1930 ind. m-2 in 1984 to 2551 ind. m-2 1985; however the difference was not significant (Table 2.2). Polychaete abundance at E3 had significantly decreased from 2063 ind. m-2 in 1984 to 1364 ind. m-2 in 1985. The number of polychaete specimens was not constant among stations of the same depths. Polychaete abundance tended to increase from northwest to southeast among the four stations at 350 m (E1 stations) and the six stations at 625 m (E2 stations). Conversely, the lowest polychaete density at 850 m occurred at the southeastern stations E3 and E3b (Fig. 2.5). At the MT transect, the shallowest stations MT1 and MT2 had higher abundances than the nearby C transect stations of comparable depths and sampled during the same DGoMB cruises. During the first DGoMB cruise in 2000, more than 2500 ind. m-2 were present at MT1 and MT2, and density at MT3 was only slightly lower. Numbers steeply decreased below 1000 m where station MT3 was located (Fig. 2.6). At station MT4 in approximately 1400 m depth, polychaetes averaged 1314 ind. m-2, at MT5 466 ind. m-2, and 166 ind. m-2 at MT6. In 2001 polychaete abundance was decreased at MT1, albeit not significantly. At MT3 the decrease was more pronounced (Fig. 2.6) and highly significant (Table 2.2). Abundance at MT6 was almost unchanged. In 2002 polychaetes reached an average abundance of 3771 ind. m-2 at MT1, the highest density of polychaetes observed at any of the stations at any sampling period included in this study. However, only two cores had been retrieved, therefore statistical power was low and significant changes could not be detected between the three sampling periods at station MT1 (Table 2.2). 160 TABLE 2.2 p-values of ANOVAs on polychaete abundance at E and MT transect stations of different sampling periods. n.s. = p-value not significant. MT1 MT3 MT6 Jun 00 vs. Jun 01 n.s. p<0.005 n.s. Jun 00 vs. Aug 02 n.s. Jun 01 vs. Aug 02 n.s. Apr 84 vs. Apr 85 E1 E2 E3 E5 n.s. n.s. p<0.05 n.s. B) Diversity The polychaete communities of the different stations at transect C clustered into four groups (Fig. 2.7). One group consisted of the shallow upper slope assemblages of stations C1, including all four different sampling periods, and C6. The depth range of the samples of this cluster was approximately 320 to 500 m. The second cluster included stations C2 and C3 of all three sampling periods, respectively, located in depths between about 600-900 m and station C7 sampled twice during DGoMB at approximately 1070 m. The next cluster contained assemblages at stations C4 including all four sampling periods, C8, and C9, in depths between 1150 m and 1500 m. The polychaete community of station C7, sampled in approximately 1020 m during NGoMCS, also clustered with these deeper stations. Among all stations sampled repeatedly, polychaete diversity had shifted most at C7. In 1984 station C7 was most similar to the deeper stations C4, C8, and C9, in 2000 and 2001 the station was most similar to the next shallower stations C2 and C3. The fourth cluster included the lower slope stations C5, C12, and C14, in depths between approximately 2400 and 3000 m. NGoMCS samples of the stations C11 and C12 were excluded because they contained less than 100 specimens. 161 162 FIGURE 2.6 Polychaete abundance of different stations and sampling periods at the Mississippi Trough. Error bars indicate the standard error. Stations are arranged according to increasing depth from left to right. Sampling periods are indicated by different colors (see legend). 163 FIGURE 2.7 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the central transect. Different stations are represented by different symbols and colors. Sampling periods are represented by cruise abbreviations (N1-3 & D1-2) as defined in Materials & Methods. It is noteworthy that a consistent trajectory occurred in the polychaete communities of stations C1, C2, and C3 sampled during three consecutive NGoMCS cruises: stations had an approximate linear trend in the ordination plot with the samples of November 1983 on bottom, samples of April 1984 in the middle, and samples of November 1984 on top (Fig. 2.7). During the approximately sixteen years between the third NGoMCS cruise and the first DGoMB cruise, the trend in the polychaete community diversity at station C1 reversed and the assemblage returned beyond the position of the first NGoMCS cruise (Fig. 2.7). Similarly, in the transition of station C4 the polychaete community of the first DGoMB cruise approximately returned to the position of the first NGoMCS cruise after a non-linear trajectory between the three NGoMCS samples (Fig. 2.7). Diversity of the polychaete communities at C1 was significantly different between each sampling period, except between November 1983 and late May 2000 (Table 2.3). At each sampling event Spionidae, Paraonidae, Nephtyidae, Capitellidae, and Opheliidae were among the most characteristic families of the assemblages (Table 2.4). Two different patterns of change occurred between the three NGoMCS sampling periods (Table 2.5). First, the numerically dominant Spionidae, Capitellidae, Syllidae, and Lumbrineridae were more abundant in April 1984 and therefore contributed more to the dissimilarity between spring and fall samples. Second, families that either continuously increased (e.g., Ampharetidae and Nephtyidae) or decreased (e.g., Amphinomidae and Opheliidae) contributed most to the dissimilarity between the samples of November 1983 and November 1984. In 2000 Ampharetidae had decreased to levels found during the first NGoMCS cruise. Syllidae were more abundant than in any of the NGoMCS samples. 164 TABLE 2.3 p-values of ANOSIMs on polychaete diversity at C and E transect stations of different sampling periods. Brackets indicate numbers of permutations with R equal or bigger, than the real dataset out of all possible permutations. n.s. = p-value not significant. C1 C2 C3 Nov 1983 vs. Apr 1984 p<0.005 [2/462] n.s. Nov 1983 vs. Nov 1984 p<0.05 [10/462] Apr 1984 vs. Nov 1984 p<0.01 [3/462] C7 C4 C5 n.s. n.s. n.s. p<0.01 [4/462] n.s. n.s. n.s. p<0.005 [1/462] n.s. n.s. n.s. Apr 1984 vs. May 1985 165 Nov 1983 vs. Jun 2000 n.s. n.s. Apr 1984 vs. Jun 2000 p<0.05 [1/84] n.s. Nov 1984 vs. Jun 2000 p<0.05 [2/56] Nov 1984 vs. Jun 2001 Nov 83 vs. Jun 00 + 01 pooled Jun 2000 vs. Jun 2001 n.s. n.s. p<0.005 [1/462] n.s. n.s. E1 E2 E3 E5 n.s. p<0.05 [1/84] n.s. n.s. TABLE 2.4 Results of the SIMPER analysis. List of polychaete families most characteristic for each station and sampling period. Abundance values are rounded to the nearest integer. Overall average similarity = 62.25 C1 (November 1983) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 357 14.84 23.84 9.51 Paraonidae 226 10.85 17.43 8.94 Nephtyidae 85 6.83 10.98 4.75 Capitellidae 62 5.20 8.34 5.16 Cirratulidae 47 4.50 7.22 3.37 Onuphidae 47 4.37 7.01 5.59 Opheliidae 105 3.85 6.19 1.33 Cossuridae 27 2.04 3.27 0.76 Overall average similarity = 73.10 C1 (April 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 821 16.14 22.09 7.25 Paraonidae 281 8.85 12.11 4.65 Nephtyidae 95 5.05 6.91 5.00 Capitellidae 123 4.89 6.69 2.23 Ampharetidae 91 4.54 6.20 3.11 Opheliidae 70 4.28 5.86 3.14 Onuphidae 60 4.17 5.70 9.02 Lumbrineridae 46 3.34 4.57 4.82 Overall average similarity = 61.08 C1 (November 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 396 14.30 23.41 5.40 Paraonidae 240 10.55 17.27 4.48 Ampharetidae 88 7.68 12.57 3.56 Nephtyidae 139 6.58 10.77 3.36 Capitellidae 59 6.23 10.20 4.10 Opheliidae 50 5.52 9.04 7.20 Cirratulidae 34 3.41 5.59 1.14 Hesionidae 34 2.73 4.46 1.12 166 TABLE 2.4 (continued) Overall average similarity = 70.55 C1 (June 2000) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Paraonidae 323 9.89 14.02 5.15. Spionidae 352 9.37 13.28 4.22 Syllidae 112 5.59 7.93 4.33 Opheliidae 85 5.03 7.12 6.40 Capitellidae 62 4.73 6.71 5.90 Nephtyidae 81 4.54 6.44 3.79 Cirratulidae 77 4.37 6.20 2.68 Glyceridae 25 2.95 4.18 29.42 Overall average similarity = 65.94 C2 (November 1983) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 363 11.15 16.92 7.53 Opheliidae 187 8.50 12.90 5.64 Paraonidae 152 5.98 9.08 2.72 Syllidae 120 5.54 8.40 3.10 Lacydoniidae 53 4.27 6.47 10.50 Trichobranchidae 82 4.21 6.38 2.86 Pilargidae 123 3.71 5.62 1.11 Capitellidae 35 3.21 4.86 6.11 Overall average similarity = 74.37 C2 (April 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 754 11.92 16.02 17.00 Syllidae 277 6.20 8.34 4.38 Opheliidae 291 6.04 8.12 3.10 Paraonidae 232 5.37 7.21 4.40 Trichobranchidae 193 4.61 6.19 2.30 Capitellidae 147 4.08 5.49 2.57 Pilargidae 112 3.95 5.31 3.44 Ampharetidae 109 3.53 4.75 3.07 167 TABLE 2.4 (continued) Overall average similarity = 53.72 C2 (November 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 210 11.17 20.79 4.10 Syllidae 88 6.94 12.93 2.76 Onuphidae 53 6.68 12.43 3.18 Trichobranchidae 67 6.36 11.83 2.42 Maldanidae 35 5.42 10.09 3.56 Pilargidae 81 4.46 8.30 1.30 Paraonidae 91 4.38 8.15 1.31 Ampharetidae 42 2.09 3.89 0.72 Overall average similarity = 54.55 C7 (November 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Maldanidae 1249 11.71 21.47 1.81 Spionidae 277 5.43 9.94 2.25 Paraonidae 133 5.41 9.91 3.35 Capitellidae 84 4.90 8.98 7.06 Sigalionidae 88 4.33 7.93 3.15 Syllidae 77 4.09 7.49 4.11 Phyllodocidae 63 3.30 6.04 3.77 Lumbrineridae 35 2.28 4.18 1.32 C7 (June 2000+2001 pooled) Overall average similarity = 73.72 Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 244 8.38 11.37 6.28 Paraonidae 195 7.43 10.07 12.43 Syllidae 195 7.30 9.90 9.08 Maldanidae 234 6.66 9.03 3.33 Opheliidae 68 3.79 5.13 4.69 Onuphidae 29 3.22 4.37 5.55 Amphinomidae 23 3.01 4.08 5.60 Orbiniidae 33 2.90 3.93 4.60 168 TABLE 2.4 (continued) Overall average similarity = 69.21 E2 (April 1984) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Paraonidae 274 7.84 11.33 19.34 Spionidae 232 7.42 10.73 7.24 Ampharetidae 246 7.01 10.13 6.30 Syllidae 189 6.41 9.25 11.81 Sabellidae 112 5.08 7.33 11.03 Maldanidae 70 4.23 6.10 29.20 Onuphidae 70 3.70 5.34 11.81 Opheliidae 84 3.22 4.65 2.54 Overall average similarity = 75.19 E2 (May 1985) Family Avg. abundance [/m^2] Avg. similarity Contrib. [%] Ratio Spionidae 421 8.01 10.66 8.01 Paraonidae 341 7.81 10.38 7.81 Syllidae 299 6.96 9.25 6.96 Ampharetidae 249 6.14 8.17 6.14 Sabellidae 169 4.55 6.05 4.55 Opheliidae 116 4.25 5.65 4.25 Orbiniidae 119 3.99 5.30 3.99 Onuphidae 74 3.32 4.42 3.32 At station C2, the diversity of the polychaete community had not changed significantly between November 1983 and April 1984, but had significantly changed in November 1984 (Table 2.3). Spionidae were most abundant and most characteristic for station C2 at all times. Opheliidae was one of the most characteristic families of the assemblages during the first two NGoMCS cruises, in November 1983 and April 1984, but decreased in November 1984. Onuphidae and Maldanidae were more characteristic families in the fall sample of 1984. Temporal differences in the abundance of Spionidae, Opheliidae, and Paraonidae contributed most to the dissimilarity between different sampling periods at station C2. 169 TABLE 2.5 Results of the SIMPER analysis. List of polychaete families that contribute most to the dissimilarity between sampling periods. Abundance values are rounded to nearest integer. Samples C1 (Nov 1983) C1 (Apr 1984) Overall avg. dissim. = 38.52 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Spionidae 357 821 3.60 9.34 2.01 Ampharetidae 15 91 2.96 7.68 2.08 Amphinomidae 73 21 2.00 5.20 1.10 Syllidae 15 63 1.92 4.99 1.48 Opheliidae 105 70 1.67 4.32 1.16 Capitellidae 62 123 1.63 4.24 1.36 Lumbrineridae 15 46 1.57 4.08 1.37 Hesionidae 9 42 1.55 4.04 1.44 Samples C1 (Nov 1983) C1 (Nov 1984) Overall avg. dissim. = 41.09 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Ampharetidae 15 88 3.79 9.24 2.04 Amphinomidae 73 4 2.67 6.49 1.02 Spionidae 357 396 2.49 6.06 1.73 Paraonidae 226 240 2.20 5.36 1.43 Opheliidae 105 50 2.06 5.00 1.13 Nephtyidae 85 139 1.98 4.81 1.19 Onuphidae 47 17 1.75 4.25 1.29 Cossuridae 27 13 1.73 4.21 1.14 Samples C1 (Apr 1984) C1 (Nov 1984) Overall avg. dissim. = 38.93 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Spionidae 821 396 3.80 9.76 1.40 Lumbrineridae 46 4 2.16 5.54 2.09 Syllidae 63 13 2.11 5.42 1.55 Paraonidae 281 240 1.93 4.95 1.38 Pilargidae 39 8 1.87 4.80 1.48 Glyceridae 28 0 1.75 4.49 2.02 Onuphidae 60 17 1.70 4.38 1.36 Capitellidae 123 59 1.66 4.27 1.55 170 TABLE 2.5 (continued) Samples C1 (Apr 1984) C1 (Jun 2000) Overall avg. dissim. = 32.46 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Spionidae 821 352 3.50 10.79 1.57 Ampharetidae 91 12 1.95 6.01 1.94 Lumbrineridae 46 6 1.63 5.02 2.05 Onuphidae 60 12 1.58 4.85 1.93 Paraonidae 281 323 1.38 4.25 1.46 Capitellidae 123 62 1.35 4.16 1.69 Syllidae 63 112 1.34 4.14 1.25 Hesionidae 42 52 1.20 3.69 1.58 Samples C1 (Nov 1984) C1 (Jun 2000) Overall avg. dissim. = 41.34 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Syllidae 13 112 3.19 7.71 2.13 Spionidae 396 352 2.45 5.94 1.25 Ampharetidae 88 12 2.45 5.92 2.26 Paraonidae 240 323 2.21 5.34 1.28 Glyceridae 0 25 1.96 4.74 7.59 Nephtyidae 139 81 1.87 4.52 1.20 Pilargidae 8 27 1.76 4.26 2.31 Cirratulidae 34 77 1.67 4.03 1.40 Samples C2 (Nov 1983) C2 (Nov 1984) Overall avg. dissim. = 48.06 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Opheliidae 187 35 4.22 8.78 1.73 Spionidae 363 210 2.91 6.06 1.54 Paraonidae 152 91 2.83 5.89 1.45 Pilargidae 123 81 2.73 5.67 1.44 Cirratulidae 62 18 2.19 4.56 1.33 Lacydoniidae 53 14 2.16 4.50 1.57 Ampharetidae 47 42 2.10 4.37 1.28 Sigalionidae 24 0 2.04 4.24 4.35 171 TABLE 2.5 (continued) Samples C2 (Apr 1984) C2 (Nov 1984) Overall avg. dissim. = 49.38 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Spionidae 754 210 4.56 9.23 2.24 Opheliidae 291 35 4.09 8.28 1.83 Capitellidae 147 28 2.82 5.71 1.50 Paraonidae 232 91 2.68 5.42 1.44 Syllidae 277 88 2.53 5.12 1.61 Lacydoniidae 81 14 2.17 4.39 1.76 Trichobranchidae 193 67 2.10 4.25 1.64 Ampharetidae 109 42 1.94 3.92 1.35 Samples C7 (Nov 1984) C7 (Jun 2000+2001 pooled) Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Maldanidae 1249 234 5.95 13.63 1.13 Spionidae 277 244 2.38 5.47 1.97 Glyceridae 147 46 2.14 4.92 1.30 Syllidae 77 195 1.54 3.53 1.46 Sigalionidae 88 19 1.42 3.25 1.63 Opheliidae 49 68 1.37 3.14 1.37 Phyllodocidae 63 12 1.36 3.12 1.50 Pilargidae 14 6 1.34 3.06 0.97 Samples E2 (Apr 1984) E2 (May 1985) Overall avg. dissim. = 28.63 Family Avg. abundance [/m^2] Avg. abundance [/m^2] Avg. dissim. Contrib. [%] Ratio Paraonidae 274 341 1.99 6.96 3.02 Sigalionidae 0 77 1.35 4.70 1.78 Orbiniidae 84 119 1.18 4.11 1.03 Lumbrineridae 77 77 1.13 3.96 1.47 Capitellidae 28 74 1.10 3.84 1.34 Lacydoniidae 14 39 1.05 3.68 1.21 Cirratulidae 49 28 1.01 3.53 1.62 Syllidae 189 299 0.96 3.34 1.39 172 Overall avg. dissim. = 54.55 Polychaete assemblages at C7 were significantly different between November 1984 and the pooled DGoMB samples from May 2000 and June 2001. Most importantly, the high numbers of Maldanidae had decreased by about 80% between November 1984 and late May 2000 (Table 2.4). This decline is reflected in the results of the SIMPER analysis, in which the maldanid polychaetes contributed by far the most to the dissimilarity between NGoMCS and DGoMB samples (Table 2.5). Polychaete assemblages at C3, C4, and C5 were not significantly different between different sampling periods (Table 2.4). SIMPER analyses were not performed at stations without significant differences among sampling periods. At transect E the stations formed four clusters (Fig. 2.8). The shallowest stations, E1, E1a, E1b, E1c, and E1d, clustered together. The polychaete community of the northwestern station E1a was the most distinctive among the shallowest stations. Stations E2, E3, and all of the affiliated stations of the same depths formed another cluster. The polychaete assemblages of stations E2 and E3 were more similar in May 1985, than they were in April 1984 (Fig. 2.8). Among the samples from 1985 station E3 curiously clustered with most of the stations of the shallower E2 transect at a similarity level of 96%. Polychaete assemblages of the northwestern station E2a and the southeastern station E3b were most distinctive within their respective cohorts of isobathic stations. Stations E4, sampled in 1984, and E5, sampled in 1985, did not cluster with any other station at a similarity level of 90%. At a similarity level of 85% all the stations of the E1-, E2-, and E3-transects and station E4 formed one large cluster (not shown). Station E5 had the most distinctive polychaete community of the transect. The assemblage of E5, sampled in 1984, was not included in the analyses because its polychaete abundance was under the threshold of 100 specimens. The only station where the polychaete community changed significantly 173 174 FIGURE 2.8 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the eastern transect. Different stations are represented by different symbols and colors. Stations of the same depth are displayed in the same color. Sampling periods are represented by cruise abbreviations (N2 & N4) as defined in Materials & Methods. between 1984 and 1985 was E2 (Table 2.3). The p-value at E1 was just slightly above the critical level of significance (Table 2.3). At station E2 the families Spionidae, Paraonidae, Syllidae, Ampharetidae, and Sabellidae were most characteristic for the communities. The increase of several abundant families, such as Paraonidae and Orbiniidae, contributed to the significant difference of the assemblages. The presence of 77 ind. m-2 of Sigalionidae in 1985 was striking because the family had been absent in the sample of 1984 (Table 2.5). At the MT transect there was also a clear transition of the polychaete assemblages with depth (Fig. 2.9). The polychaete communities of MT1 were similar throughout the three sampling periods and form one cluster. The trajectory of the assemblages between 2000 and 2002 is circular. The assemblages of stations MT2, MT3 of both sampling periods, and MT4 clustered together. The polychaete assemblages at station MT5 were most distinctive of the transect. The deep water station MT6 was excluded because polychaete abundance was below 100 specimens. I were unable to test for significant changes of the resampled stations MT1, MT3, and MT6 using ANOSIM because the maximum number of permutations was ten, and hence the smallest possible p-value was 0.1. Discussion A) Abundance At transect C I observed a strong seasonal oscillation in the abundance of polychaetes. At depths between 350 and 1500 m specimen numbers approximately doubled between November 1983 and April 1984 and, in most cases, receded to the initial level in November 1984. At the deeper station C5 the increase in spring was less pronounced. Most likely this increase in abundance 175 176 FIGURE 2.9 MDS ordination plot based on the similarity of the polychaete fauna of the different stations and sampling periods at the Mississippi Trough. Different stations are represented by different symbols and colors. Sampling periods are represented by cruise abbreviations (D1-3) as defined in Materials & Methods. was correlated to the nutrient inflow from the Mississippi-Atchafalaya river system, which peaks in the spring (Turner et al. 1998, Aulenbach et al. 2007) and triggers spring blooms (Dortch et al. 1997). The algae bloom in turn increases nutrient availability to the benthos through bentho-pelagic influx of POC (particulate organic matter). At sinking rates of 100-150 m d-1 (Lampitt 1985), detrital aggregations reach the benthos in about three days to three weeks, depending on the depths of the individual stations. The reproduction cycles of the polychaetes in this area may be either synchronized to or triggered by the increased nutrient levels. Similar increases in polychaete abundance following a pulse of organic carbon influx to the deep-sea have been observed in the Northeast Atlantic (Vanreusel et al. 2001). The lower increase in abundance during spring at station C5 may either be attributed to the longer lag between the spring bloom in the photic zone and the POC influx, the lower increase in nutrient levels reaching the benthos, or a higher portion of polychaetes with continuous, rather than seasonal reproduction. The DGoMB samples of stations C1, C4, and C12 were at a similar level as the fall samples of NGoMCS. Because the DGoMB samples were collected at a different time of the year than the NGoMCS samples, it is impossible to unravel the relative importance of seasonal and annual variations. The nutrient input from the Mississippi-Atchafalaya river system prior to the DGoMB cruises was lower than prior to spring sampling of NGoMCS. Total nitrogen input of the three combined months preceding sampling (February-April for NGoMCS and MarchMay for DGoMB) was at 830 kt in 1984, at 299 kt in 2000, and at 573 kt in 2001 (Aulenbach et al. 2007). Therefore, the peak in the polychaete abundance during spring might have been higher in 1984. However, because DGoMB samples were retrieved at a later time of the year, the spring peak of polychaete density may have subsided. 177 Station C7 had unusually high abundance in November 1984. Bamboo worms of the family Maldanidae were predominated in this sample. Distribution of the maldanids was quite patchy, which is reflected in the large standard error of the average abundance (Fig. 2.4). Gallaway (1988) found evidence of a hydrocarbon seeps in the vicinity of the station. They observed high concentrations of hydrocarbons typically found near seeps and bivalves common in chemosynthetic environments. Five specimens of an unidentified species of “Pogonophora” were also found in the replicate with the highest polychaete density (5368 ind. m-2). The pogonophorans, now considered polychaetes of the family Siboglinidae, lack a digestive tract and rely exclusively on endosymbiotic, chemoautotrophic bacteria for their nutrition. Therefore, they are obligate dwellers of hydrocarbon seeps (and hydrothermal vents in other oceans). The same replicate had conspicuously high numbers of Maldanidae and elevated levels of Glyceridae and Terebellidae. Hydrocarbon seeps are common in the Gulf of Mexico and abundance and biomass in their vicinity are much higher than in the surrounding deep-sea (MacDonald et al. 1989). Thus, the considerable difference in polychaete abundance at station C7 is likely attributed to the coincidental sampling at or near a hydrocarbon seep during the third NGoMCS cruise. Another interesting observation is that polychaete density did not consistently decrease with depth among the stations between 325 and 1500 m as might be expected. Instead, a steep drop of polychaete abundance occurred between 1500 and 2100 m. In contrast, Carvalho et al. (2013) found a steady exponential decline of polychaete abundance and biomass with depth at the northern Gulf of Mexico continental slope. At C4 five of the six replicates of the fall cruise in November 1984 had lower densities (484-1537 ind. m-2) than the six replicates of the spring cruise in April of the same year 178 (1835-2505 ind. m-2). However, one replicate of the fall samples had an unusually high number of 3453 ind. m-2, mainly attributed to the high density of the polychaete family Maldanidae (1934 ind. m-2). This replicate inflated the standard error of the average abundance at of the fall 1984 samples from C4 substantially (Fig. 2.4) and caused the p-value to increase over the significance threshold (Table 2.1). At transect E abundance was not constant among stations of the same depth. Therefore, other variables, such as sediment composition, may have an important role in shaping the polychaete communities. The northwestern stations E1a and E2a were characterized by a considerably higher proportion of clay and lower proportion of sand, compared to the respective isobathic stations. Both sites had lower densities than the other stations of the same depth. Conversely, at 850 m the southeastern stations E3 and E3b had the lowest polychaete densities, even though there was not much of a difference in the sediment composition. The relative amounts of clay had increased and the relative amount of sand had decreased from April 1984 to April 1985 at all resampled stations of the eastern transect. The river discharge of some of the larger rivers in the northeastern Gulf of Mexico, such as the Apalachicola and Suwannee Rivers, prior to sampling in 1984 was higher, than in the following year (USGS 2013). However, the magnitude of nutrient influx through these rivers compared to the Mississippi Atchafalaya River system is minor. Additionally, the Florida shelf is broad and most of the primary and secondary production induced by the nutrient inflow may not reach the continental slope. A significant decrease of abundance was observed at E3. In contrast, polychaete abundance increased at E2, albeit the p-value was slightly above 0.05. The opposing changes in polychaete abundance at E2 and E3 may infer events that affected the local, rather than the regional polychaete fauna. Some phenomena common in the Gulf of Mexico that may affect the abundance of local polychaete 179 faunas include eddies and turbidity currents. Cyclonic eddies cause localized upwelling of cold nutrient rich deep water in their cores. They are localized hotspots of primary production and zooplankton density (Zimmermann & Biggs 1999). Conversely, anticyclonic eddies have cores of warm nutrient depleted surface waters with low levels of primary and secondary production (Biggs 1992). Eddies, as small as tens of kilometers in diameter, can substantially alter local nutrient availability and phytoplankton abundance, and hence change POC influx to the continental slope benthos (Ressler & Jochens 2003). Turbidity currents can extinguish most of the local fauna (Young & Richardson 1998). If such an event had happened shortly prior to sampling, polychaete communities may not have had enough time to recover and reach full carrying capacity. Hydrocarbon seeps also change local polychaete fauna profoundly. Single specimens of unidentified species of “Pogonophora” were collected at E2e, the station with the highest abundance of all E-transect stations, and at E3c, the station with the highest abundance of its depth, indicating the presence of hydrocarbon seeps in the vicinity of the sampling site. Curiously, another unidentified specimen of “Pogonophora” was collected at E3 in 1985, the station with the lowest abundance at 850 m. The high density of polychaetes at transect MT, was most likely caused by the proximity to the Mississippi River mouth. Additionally, the Mississippi Trough may act as a nutrient trap. Compared to the nearby C transect, polychaete abundance at transect MT was increased between approximately 350 and 1500 m. The deeper stations MT5 and MT6 had densities similar to C stations of comparable depths, C14 and C12. Stations MT1 and MT3 had lower polychaete densities during the 2001 sampling period. This was surprising considering that in 2001 the nutrient input from the Mississippi River was higher, than in 2000 (Aulenbach et al. 2007). However, it was in accordance with the observation that the macrofauna had significantly 180 decreased at virtually all resampled stations (several of which had not been included in this study) during the second DGoMB cruise in 2001 (Rowe & Kennicutt 2009). The reason for the decline is unknown. The higher abundance at MT1 in the 2002 sample was in accordance with the higher Mississippi nutrient influx in 2002, compared to the two previous years (Aulenbach et al. 2007). The only highly significant change in polychaete abundance at transect MT was the decrease at MT3 between 2000 and 2001 (Table 2.2). The other comparisons failed the significance level of p=0.05. However, statistical power was low as only three replicates of the DGoMB samples from 2000 and 2001 and two replicates from 2002 were examined. Abundance and biomass may not necessarily co-vary. In the spawning season abundance typically increases, whereas biomass may change only slightly. However, as the peak abundance is decreasing, biomass may still increase as the prevailing individuals keep growing (Billett et al. 2001). Furthermore, the mean body sizes of polychaetes decrease with increasing depths (Carvalho et al. 2013). B) Diversity At all transects polychaete assemblages clustered according to depth. The findings that the polychaete fauna changed gradually down the continental slope corroborate the observations by Wei et al. (2010) on the macrofauna of the same area. Hydrostatic pressure, temperature, light intensity, oxygen levels, contaminants, and most importantly, nutrient availability, shape the assemblages (Carney 2005). Furthermore, changes in biodiversity were independent from abundance. Stations shallower than 1500 m had significant seasonal changes in abundance that were not mirrored in the ordination of diversity measurements. 181 The diversity of the polychaete assemblages at C1 and C4 changed little over ~16-17 years. Even more intriguing is that the DGoMB samples are most similar to the samples of the first NGoMCS cruise, suggesting that the short-term trajectory of the polychaete communities observed between November 1983 and November 1984 had reversed. A possible scenario to explain these observations may infer extended periods of steady conditions and episodes of disturbances or catastrophic events. Prevailing stable conditions may enable a slow, consistent shift of the communities in favor of polychaetes that are competitively superior in the struggle for the limited resources. Disturbances and catastrophes, on the other hand, may result in the local extinction of much of the local polychaete fauna and enable opportunistic species that are competitively inferior to quickly resettle the available spatial resources. Common natural catastrophic events at the northern Gulf of Mexico continental slope may include turbidity currents (Niedoroda et al. 2003) and oil contamination from natural seeps (Kennicutt et al. 1989). Anthropogenic impacts, such as trawling (Watling & Norse 1998) and oil spills may have similar impacts, but they may differ considerably in scale (Montagna et al. 2013). The most significant change between sampling events at a single location occurred at C7. As mentioned above, this change was most likely not a temporal shift of the polychaete community, but was rather caused by the coincidental sampling near a hydrocarbon seepage. When the six NGoMCS replicates of station C7 were plotted separately in an MDS plot, three of them that had no elevated abundances were located close to the replicates of C3, whereas three replicates with increased abundance were closer to the deeper stations (data not shown). This suggests that three of the replicates were not retrieved from the vicinity of a hydrocarbon seep and that their polychaete diversity was most similar to that of station C3. The one replicate with five specimens of “Pogonophora” and high densities of Maldanidae was most likely located 182 close to the hydrocarbon seepage. Two other replicates without “Pogonophora” but with elevated numbers of several polychaete families had intermediate positions in the MDS plot, suggesting they were collected at the outer perimeter of a seep. Interestingly, the hydrocarbon seep seemed to attract a mixture of specialized species and opportunistic polychaetes that are more typically found at the deeper stations C4, C8, and C9. When plotted in a two-dimensional MDS plot, the depth-related changes of the polychaete assemblages were not linear in any of the transects, but followed a parabolic trajectory. This pattern is reminiscent of the unimodal regression lines of α-diversity and depth, indicating that biodiversity is highest at intermediate depths. The latter phenomenon has been observed in many areas of the world ocean and for different taxa, including polychaetes (e.g., Vinogradova 1962, Rex 1981, Pineda & Caswell 1998). Conclusion The most important findings of this study are: 1) The Morisita-Horn index proved to be a useful tool for measuring species turnover rates among samples with different sample sizes. 2) Polychaete abundance at the central Gulf of Mexico continental slope undergoes conspicuous seasonal cycles. Specimen counts in spring were approximately twice as high as in fall. Most likely the seasonal fluctuation of food availability affects the life histories of many polychaete species. 3) Annual variations in polychaete abundance may be considerable. In the central Gulf and the Mississippi Trough annual variations of the nutrient inflow from the Mississippi 183 Atchafalaya River system may have an important role. Sediment composition and oceanographic processes that alter nutrient availability may affect polychaete abundance. 4) At the central and eastern slope polychaete abundance did not consistently decline with increasing depth between 350 and 1500 m, but sharply declined below 1500 m. At the Mississippi Trough abundance began to decline between 700 and 900 m, however the polychaete population density was higher than at the central transect as deep as 1500 m. 5) Changes in biodiversity were independent from changes in abundance. Doubling in abundance during spring did not affect β-diversity measurements. Also, communities changed consistently with depth, while abundances did not. 6) Depth (and its correlated variables), sediment composition, local oceanographic processes, and hydrocarbon seeps are crucial in shaping the assemblages. 7) At stations C1 and C4 a linear short-term (~ 1 year) shift of the polychaete community had reversed over a longer time period (~ 16-17 years). I hypothesize that this is caused by the alternation between steady conditions that favor strong competitors and perpetual catastrophic events that favor opportunists. 8) Depth related changes in polychaete diversity yield approximately parabolic trajectories in two-dimensional MDS plots. Acknowledgements The NGoMCS study was funded by the Minerals Management Service (MMS) of the US department of the Interior (Contract 14-12-0001-30212 with LGL Ecological Research Associates, Inc. and Texas A&M University, PI Benny J. Gallaway). The DGoMB study was 184 funded by MMS of the US department of the Interior (Contract 1435-01-99-CT-30991 (M99PC00001) with Texas A&M University, co-PIs Gilbert T. Rowe and Mahlon C. Kennicutt II). I thank Gilbert Rowe (Texas A&M University at Galveston) for making samples of the DGoMB survey available. The late Guinn Fain Hubbard is thanked for identifying a significant portion of the polychaetes of both surveys. Gilbert Rowe, Anja Schulze, Russell Carvalho (all Texas A&M University at Galveston), Chih-Lin Wei (Memorial University of Newfoundland, formerly Texas A&M University at Galveston), and Clifton Nunnally (University of Hawaii at Manoa, formerly Texas A&M University at Galveston) are thanked for facilitating the sample transfer, providing unpublished data sets of the DGoMB study, and providing lab space during a visit at Texas A&M University at Galveston. Greg Boland (Bureau of Ocean Energy Management, Research and Enforcement) and Mary Wicksten (Texas A&M University) are thanked for providing unpublished data sets of the NGoMCS study. The quality of the manuscript was improved by Paul Montagna’s thorough review. I thank the Harte Research Institute for providing office space and computational resources. The College of Science and Engineering at Texas A&M University–Corpus Christi is thanked for the support through teaching assistantships from fall semester 2008 to spring semester 2011. Paul Montagna is thanked for his support through a research assistantship since the fall semester 2011. During the summer semesters of the years 2010-2013 support was provided through MARB scholarships by the College of Science & Engineering at Texas A&M University – Corpus Christi. 185 References Aller, J.Y. (1997) Benthic community response to temporal and spatial gradients in physical disturbance within a deep-sea western boundary region. Deep-Sea Research I, 44(1), 3969. Aulenbach, B., Buxton, H., Battaglin, W., & Coupe, R.(2007) Streamflow and nutrient fluxes of the Mississippi-Atchafalaya River Basin and subbasins for the period of record through 2005. U.S. Geological Survey Open-File Report 2007-1080. Available from http://toxics.usgs.gov/pubs/of-2007-1080/index.html (accessed 7 June 2013). Beesley, P.L., Ross, G.J.B. & Glasby, C.J. (Eds.) (2000) Polychaetes & Allies: The southern synthesis, Fauna of Australia. Vol. 4A. Polychaeta. Pogonophora. Echiura. Sipuncula. CSIRO Publishing, Melbourne, xii 465 pp. Bertrand, Y., Pleijel, F. & Rouse, G.W. (2006) Taxonomic surrogacy in biodiversity assessments, and the meaning of Linnean ranks. Systematics and Biodiversity, 4(2), 149159. Biggs, D.C. (1992) Nutrients, plankton, and productivity in a warm-core ring in the western Gulf of Mexico. Journal of Geophysical Research: Oceans, 97(C2), 2143-2154. Billett, D.S.M., Bett, B.J., Rice, A.L., Thurston, M.H., Galéron, J., Sibuet, M. & Wolff, G.A. (2001) Long-term change in the megabenthos of the Porcupine Abyssal Plain (NE Atlantic). Progress in Oceanography, 50, 325-348. Carney, R.S. (2005) Zonation of deep biota on continental margins. Oceanography and Marine Biology: An Annual Review, 43, 211-278. 186 Carvalho, R., Wei, C.-L., Rowe, G. & Schulze, A. (2013) Complex depth-related patterns in taxonomy and functional diversity of polychaetes in the Gulf of Mexico. Deep-Sea Research I, 80, 66-77. Clarke, K.R. & Gorley, R.N. (2006) PRIMER v6: User Manual/Tutorial. PRIMER-E, Plymouth, 190 pp. Dortch, Q., Robichaux, R., Pool, S., Milsted, D., Rabalais, N.N., Soniat, T.M., Fryxell, G.A., Turner, R.E. & Parsons, M.L. (1997) Abundance and vertical flux of Pseudo-nitzschia in the northern Gulf of Mexico. Marine Ecology Progress Series, 146, 249-264. Drazen, J.C., Baldwin, R.J. & Smith Jr., K.L. (1998) Sediment community response to a temporally varying food supply at an abyssal station in the NE Pacific. Deep-Sea Research II, 45, 893-913. Fauchald, K. & Jumars, P.A. (1979) The diet of worms: a study of polychaete feeding guilds. Oceanography and Marine Biology – An Annual Review, 17, 193-284. Galéron, J., Menot, L., Renaud, N., Crassous, P., Khripounoff, A., Treignier, C. & Sibuet, M. (2009) Spatial and temporal patterns of benthic macrofaunal communities on the deep continental margin in the Gulf of Guinea. Deep-Sea Research II, 56(23), 2299-2312. Gallaway, B.J. (Ed.) (1988) Northern Gulf of Mexico continental slope study, final report: Year 4. Volume II: Synthesis report. Final report submitted to the Minerals Management Service, New Orleans, LA. Contract No. 14-12-0001-30212. OCS Study/MMS 88-0053, 378 pp. 187 Glover, A.G., Gooday, A.J., Bailey, D.M., Billett, D.S.M., Chevaldonné, P., Colaço, A., Copley, J., Cuvelier, D., Desbruyères, D., Kalogeropoulou, V., Klages, M., Lampadariou, N., Lejeusne, C., Mestre, N.C., Paterson, G.L.J., Perez, T., Ruhl, H., Sarrazin, J., Soltwedel, T., Soto, E.H., Thatje, S., Tselepides, A., Van Gaever, S. & Vanreusel, A. (2010) Temporal change in deep-sea benthic ecosystems: a review of the evidence from recent time-series studies. Advances in Marine Biology, 58, 1-95. Horn, H. (1966) Measurement of "overlap" in comparative ecological studies. The American Naturalist, 100, 419-424. Hubbard, G.F. (1995) Benthic polychaetes from the northern Gulf of Mexico continental slope. Dissertation. Texas A&M University, College Station, Texas, xiv 197 pp. Kennicutt II, M.C., Brooks, J.M. & Burke, R.A. (1989) Hydrocarbon seepage, gas hydrates, and authigenic carbonate in the northwestern Gulf of Mexico. Proceedings of the 21st Offshore Technology Conference, 649-654. Lampitt, R.S. (1985) Evidence for the seasonal deposition of detritus to the deep-sea floor and its subsequent resuspension. Deep Sea Research Part A. Oceanographic Research Papers, 32(8), 885-897. Levin, L., Gutiérrez, D., Rathburn, A., Neira, C., Sellanes, J., Muñoz, P., Gallardo, V. & Salamanca, M. (2002) Benthic processes on the Peru margin: a transect across the oxygen minimum zone during the 1997-98 El Niño. Progress in Oceanography, 53, 1-27. MacDonald, I.R., Boland, G.S., Baker, J.S., Brooks, J.M., Kennicutt II, M.C. & Bidigare, R.R. (1989) Gulf of Mexico hydrocarbon seep communities. Marine Biology, 101(2), 235-247. 188 Montagna, P.A., Baguley, J.G., Cooksey, C., Hartwell, I., Hyde, L.J., Hyland, J.L., Kalke, R.D, Kracker, L.M., Reuscher, M. & Rhodes, A.C.E. (2013) Deep-sea benthic footprint of the Deepwater Horizon blowout. PLoS ONE, 8(8), e70540. doi:10.1371/journal.pone.0070540. Montagna, P.A. & Harper Jr., D.E. (1996) Benthic infaunal long-term response to offshore production platforms. Canadian Journal of Fisheries and Aquatic Sciences, 53, 25672588. Niedoroda, A.W., Reed, C.W., Hatchett, L., Young, A., Lanier, D., Kasch, V., Jeanjean, P., Orange, D., & Bryant, W. (2003) Analysis of past and future debris flows and turbidity currents generated by slope failures along the Sigsbee escarpment in the deep Gulf of Mexico. Proceedings of the 35th Annual Offshore Technology Conference, OTC paper No. 15162. Olsgard, F., Brattegard, T. & Holthe, T (2003) Polychaetes as surrogates for marine biodiversity: lower taxonomic resolution and indicator groups. Biodiversity and Conservation, 12(5), 1033-1049. Pequegnat, W. (1983) The ecological communities of the continental slope and adjacent regimes of the northern Gulf of Mexico. Prepared by Tereco Corporation. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. Contract No. AA851-CT-1-12, 398 pp. Pineda, J. & Caswell, H. (1998) Bathymetric species-diversity patterns and boundary constraints on vertical range distributions. Deep-Sea Research II, 45(1-3), 83-101. 189 Ressler, P.H. & Jochens, A.E. (2003) Hydrographic and acoustic evidence for enhanced plankton stocks in a small cyclone in the northeastern Gulf of Mexico. Continental Shelf Research, 23(1), 41-61. Rex, M.A. (1981) Community structure in deep-sea benthos. Annual Review of Ecology and Systematics, 12, 331-353. Rowe, G.T. & Kennicutt II, M.C. (Eds.) 2009. Northern Gulf of Mexico continental slope habitats and benthic ecology study: Final report. U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2009-039. 456 pp. Turner, R.E., Qureshi, N., Rabalais, N.N., Dortch, Q., Justic, D., Shaw, R.F. & Cope, J. (1998) Fluctuating silicate: nitrate ratios and coastal plankton food webs. Proceedings of the National Academy of Sciences of the United States of America, 95(22), 13048-13051. USGS (2013) Surface water data for USA: USGS surface-water monthly statistics. Available from: http://waterdata.usgs.gov/nwis/monthly? (accessed 25 June 2013). Vanreusel, A., Cosson-Sarradin, N., Gooday, A.J., Paterson, G.L.J., Galéron, J., Sibuet, M. & Vincx, M. (2001) Evidence for episodic recruitment in a small opheliid polychaete species from the abyssal NE Atlantic. Progress in Oceanography, 50(1-4), 285-301. Vinogradova, N.G. (1961) Vertical zonation in the distribution of deep-sea benthic fauna in the ocean. Deep-Sea Research, 8 (3-4), 245-250 [Translated from the original Russian paper published 1958 in Trudy Instituta Oceanologii, Akademiia Nauk S.S.S.R., 27, 86-122.] Wang, Y. (2004) Patterns in biodiversity and distribution of benthic Polychaeta in the Mississippi Canyon, northern Gulf of Mexico. Dissertation. Texas A&M University, College Station, Texas, xiv 162 pp. 190 Warwick, R.M. (1988) Analysis of community attributes of the macrobenthos of Frierfjord/Langesundfjord at taxonomic levels higher than species. Marine Ecology Progress Series, 46, 167-170. Watling, L. & Norse, E.A. (1998) Disturbance of the seabed by mobile fishing gear: a comparison to forest clearcutting. Conservation Biology, 12(6), 1180–1197. Wei, C.-L., Rowe, G.T., Hubbard, G.F., Scheltema, A.H., Wilson, G.D.F., Petrescu, I., Foster, J.M., Wicksten, M.K., Chen, M., Davenport, R., Soliman, Y. & Wang, Y. (2010) Bathymetric zonation of deep-sea macrofauna in relation to export of surface phytoplankton production. Marine Ecology Progress Series, 399, 1-14. Wolda, H. (1981) Similarity indices, sample size and diversity. Oecologia, 50, 296-302. Young, D.K. & Richardson, M.D. (1998) Effects of waste disposal on benthic faunal succession on the abyssal seafloor. Journal of Marine Systems, 14(3-4), 319-336. Zimmermann, R.A. & Biggs, D.C. (1999) Patterns of distribution of sound-scattering zooplankton in warm- and cold-core eddies in the Gulf of Mexico, from a narrowband acoustic Doppler current profiler survey. Journal of Geophysical Research: Oceans, 104(C3), 5251-5262. 191 CHAPTER III Cladistic Analysis of the Family Paraonidae (Annelida: Polychaeta) and the Genera Cirrophorus and Paradoneis Based on Morphological Characters Abstract In this first cladistic study on the phylogeny of Paraonidae, morphological characters from type specimens and original descriptions were used in two maximum parsimony analyses. The first analysis was performed on the genus level. It included all paraonid genera, except for Aparaonis, which was found invalid, and outgroup genera of the morphologically most similar polychaete families Cossuridae, Orbiniidae, and Questidae. Monophyly of Paraonidae was supported; complete fusion of prostomium and peristomium and dorsal location of the anus are synapomorphies of Paraonidae. Paraonides is the sister taxon to the Cirrophorus – Paradoneis clade. The second analysis was performed on the species level and included all Cirrophorus and Paradoneis species and representatives of the paraonid genera Levinsenia and Paraonides as outgroup taxa. Three sister taxa that share the conspicuous elongation of notopodial postchaetal lobes in pre-anal segments were supported: 1) Paraonides, which lacks modified notochaetae, 2) a clade consisting of Paradoneis drachi and P. spinifera, which are characterized by the possession of notochaetal spines, and 3) a clade consisting of the remaining Cirrophorus and Paradoneis species, which all have bifurcate notochaetae. The two species with notochaetal spines are classified in a new genus. The analysis yielded a large number of most parsimonious cladograms and a strict consensus tree with few resolved phylogenetic relationships among the Cirrophorus and Paradoneis species with bifurcate notochaetae. The poor resolution of the 192 phylogenetic relationships is caused by the low number of morphological characters in the simplistic paraonid polychaetes. According to the majority rule consensus tree, the prostomial antenna is a homoplastic character that has developed twice within the species complex. Therefore, Cirrophorus is regarded polyphyletic and Paradoneis is considered paraphyletic. I suggest that both genera be synonymized, with Cirrophorus being the senior synonym. Molecular markers or ultrastructural characters should be used to supplement the morphological data in future cladistic studies of Paraonidae. Key words: maximum parsimony analysis, new genus, paraonids, phylogeny, systematics Introduction A) Biology and ecology of Paraonidae Paraonidae is a family of subsurface deposit-feeding polychaetes. Being active burrowers they use an unarmed pharynx to ingest diatoms and foraminiferans (Röder 1971, Gaston et al. 1992). Paraonids are usually among the predominant polychaetes in a variety of natural habitats, such as sea-grass beds (Brito et al. 2005), estuaries (Chainho et al. 2006), deep-sea basins (Fauchald & Hancock 1981, Fiege et al. 2010), seamounts (Surugiu et al. 2008), oxygen minimum zones (Hughes et al. 2009), manganese nodules (Thiel et al. 1993), and artificial habitats, such as fish cages (Alston et al. 2005, Diaz-Castañeda & Valenzuela-Solano 2009). They are also known from cold seeps (Levin et al. 2003, Levin et al. 2006) and whale falls (Fujiwara et al. 2007). Because of their high abundance in most habitats and areas of the world’s oceans, polychaetes of the family Paraonidae are an integral part of the marine food web. They are prey 193 of several fish species, including red mullet (Bautista-Vega et al. 2008), razorfish (Castriota et al. 2005), winter flounder (Armstrong 1995), sandperch (González & Oyarzun 2003), Dover sole (Gabriel & Pearcy 1981), and emerald rockcod (Vacchi et al. 1994). They can contribute more than 5% of the stomach contents of juvenile fish (Vacchi et al. 1994, Fairchild et al. 2008). Other consumers of Paraonidae are crustaceans, such as endobenthic amphipods (Dauby et al. 2001), brown shrimp (Feder & Pearson 1988), and brachyuran crabs (Petti et al. 1996). Known parasites of paraonid polychaetes include a copepod species (Laubier & Carton 1973) and polychaetes of the genus Drilonereis (appendix of Blake et al. 1983). B) Taxonomic history of Paraonidae The earliest paraonid species were described in the nineteenth century. They were initially described in the families Spionidae Grube, 1850, Cirratulidae Carus, 1863, and Levinseniidae Mesnil & Caullery, 1898. The family Paraonidae was erected by Cerruti (1909). Number, names, and diagnoses of paraonid genera have changed many times over the course of time. The most comprehensive revision of the family was provided by Strelzov (1973). He considered six genera, Aricidea Webster, 1879, Cirrophorus Ehlers, 1908, Paraonella Strelzov, 1973, Paraonis Cerruti, 1909, Sabidius Strelzov, 1973, and Tauberia Strelzov, 1973 to be valid, and the genus Aparaonis Hartman, 1965 as doubtful. Subsequently, Katzmann & Laubier (1975) rejected the synonymy of the genera Cirrophorus, Paraonides Cerruti, 1909, and Paradoneis Hartman 1965. In the case of Paraonides, Strelzov based the synonymy on the examination of non-type specimens that were likely misidentified. Therefore, Paraonides has been considered valid with Paraonella being its junior synonym (Katzmann & Laubier 1975). The synonymy of Cirrophorus and Paradoneis has been controversial, but most authors have rejected it (see next 194 subsection). Levinsenia Mesnil, 1897 was given precedence over Tauberia (Melville 1979). Strelzov (1973) subdivided the speciose genus Aricidea into four subgenera, including the newly described Acesta Strelzov, 1973, Allia Strelzov, 1973, and Aricidea Strelzov, 1973, as well as Aedicira Hartman, 1957, formerly considered a genus. Acesta was later renamed Acmira because of a homonymy (Hartley 1981). The four subgenera of Aricidea were given genus rank by Fauchald (1977). However, Fauchald (1977) did not provide the reason for his decision to change their taxonomic status, and most subsequent authors did not follow his opinion. In conclusion, the family Paraonidae consisted of the genera Aparaonis, Aricidea (with its four subgenera Acmira, Aedicira, Allia, and Aricidea), Cirrophorus, Levinsenia, Paradoneis, Paraonides, Paraonis, and Sabidius at the time this study was conducted. C) Morphology and taxonomy of Cirrophorus and Paradoneis In contrast to other paraonid genera that either possess only simple capillary chaetae or modified neurochaetae in posterior segments, Cirrophorus and Paradoneis have modified notochaetae that usually commence in an anterior segment. These chaetae are usually bifurcate. Based on thickness and shape of the tines, three main types are recognized: lyrate, acicular, and harpoonshaped. Lyrate notochaetae are relatively slender, their tines are of similar width, and they are usually hirsute, which gives them the appearance of a lyre (Fig. 3.1A). In the acicular type, the ventral tine is much sturdier whereas the dorsal tine is reduced and can, in some species, be a barely noticeable thread-like attachment (Fig. 3.1B). Harpoon-like notochaetae resemble the acicular type, but they have developed a subdistal bulge (Fig. 3.1C). Species that possess the acicular or harpoon-like type of notochaetae usually have lyrate notochaetae in anterior chaetigers. The shape of their bifurcate notochaetae then gradually changes along their body with 195 the ventral tine getting more and more pronounced and the dorsal one getting more and more reduced. The genus Paradoneis is distinguished from Cirrophorus by the absence of a prostomial antenna. Strelzov (1973) synonymized the genera because he argued that the presence of a prostomial antenna is age-dependent and therefore varies even within the same species. This synonymy has been controversial. Laubier & Ramos (1974) argued that Strelzov had based his synonymy on the examination of specimens of two distinct species, Cirrophorus lyriformis Annenkova, 1934 (with antenna) and Paradoneis armata Glémarec, 1966 (without antenna) that he had mistaken as the same species. Most authors followed the opinion of Laubier& Ramos (1974) and considered the genus Paradoneis valid. Other authors, however, followed Strelzov’s system and described new species that lack a prostomial antenna in the genus Cirrophorus. FIGURE 3.1 Different types of bifurcate notochaetae in Cirrophorus and Paradoneis species. Dorsal tines of the chaetae illustrated on the left, ventral tines on the right. A: Lyrate notochaeta; B: Acicular notochaeta; C: Harpoon-shaped notochaeta. 196 D) Phylogenetic hypotheses tested Three important questions in the systematic classification of paraonid polychaetes are: 1. Is the family Paraonidae monophyletic? 2. Are the genera Cirrophorus and Paradoneis monophyletic and therefore valid, or should they be synonymized? 3. Are the four subgenera of Aricidea monophyletic and should they have the status of subgenera or genera? In this paper I address the first two questions, whereas the third one will be dealt with in a separate treatment of the speciose genus Aricidea (Reuscher in prep.). The current, most widely accepted systematic classification will serve as null hypotheses to be tested: H1: The family Paraonidae is monophyletic H2: The genera Cirrophorus and Paradoneis are monophyletic Materials & Methods A) Common abbreviations Abbreviations used in the cladistics analyses are CI = consistency index, RI = retention index, and TL = tree length. Institutions are denoted with following acronyms: BMNH = British Museum of Natural History, London; LACM-AHF = Los Angeles County Museum of Natural History, Allan Hancock Foundation, Los Angeles; MNCN = Museo Nacional de Ciencias Naturales, Madrid; MNHN = Muséum National d’Histoire Naturelle, Paris; NMI = National Museum of Ireland, Dublin; NSMT = National Museum of Nature and Science, Tsukuba; UANL = Universidad 197 Autónoma de Nuevo León, San Nicolás de Los Garza; UP = Universitá di Pisa; USNM = National Museum of Natural History, Smithsonian Institution, Washington, D.C.; ZIN = Zoological Institute of the Russian Academy of Sciences, St. Petersburg; ZMB = Museum für Naturkunde, Berlin; ZMH = Zoologisches Museum Hamburg; ZMU = Evolutionmuseet, Uppsala. B) Material examined Type material of 25 species and one subspecies of Cirrophorus and Paradoneis were examined (Table 3.1). Type specimens of three species and one subspecies of Paradoneis were not available for examination for various reasons (see Table 3.1). In these cases, data were retrieved from original descriptions. Morphological data of the other genera and subgenera of Paraonidae were retrieved during examinations of type specimens of most described species and supplemented by original descriptions. I also examined paratypes of the outgroup taxa Scoloplos (Scoloplos) texana (5 specimens; USNM 52734) and Cossura bansei (1 specimen; USNM 172566). Data for these genera were supplemented by original descriptions of each species of the respective genera. Data of the outgroup genus Questa were taken from Giere et al. (2007). C) Taxonomic remarks based on type material examinations The monotypic genus Aparaonis Hartman, 1965 is invalid and was therefore excluded from the cladistics analysis. The holotype and only individual of Aparaonis abyssalis Hartman, 1965 is a broken specimen belonging to the family Opheliidae (pers. obs.). 198 TABLE 3.1 List of specimens examined for the cladistic analysis of the Cirrophorus – Paradoneis species complex, including the outgroup taxa. Type status indicated as H = holotype, P = paratype(s), S = syntypes, N = non-type specimen(s); numbers in brackets indicate the number of specimens examined. Acronyms of institutions are explained in Materials & Methods. Species Type Institution Collection No. Levinsenia flava (Strelzov, 1973) H ZIN 1/38025 Paraonides nordica Strelzov, 1968 H ZIN 1/14598 C. aciculatus (Hartman, 1957) N(2) 2/38011 N(1) 2/38012 N(3) 4/38013 N(1) 5/38014 H LACM-AHF P(4) Poly 494 Poly 495 C. branchiatus Ehlers, 1908 S(1) ZMB 4488 C. furcatus (Hartman, 1957) H LACM-AHF Poly 492 P(22) C. longifurcatus Hartmann-Schröder, 1965 H Poly 493 ZMH P(1) P-14850 P-14851 C. lyriformis Annenkova, 1934 S(2) ZIN 1/2396 C. miyakoensis (Imajima, 1973) H NSMT Pol. H 95 P. abranchiata (Hartman, 1965) H LACM-AHF Poly 659 P(14) Poly 660 P. americana (Strelzov, 1973) H ZIN 1/37975 P. armata Glémarec, 1966 H MNHN Poly Type 1412 P. bathyilvana Aguirrezabalaga & Gil, H MNCN 16.01/11202 2009 P(1) P. brevicirrata (Strelzov, 1973) H 16.01/11203 ZIN P(8) P. brunnea (Hartmann-Schröder & H Rosenfeldt, 1988) P(8) P. carmalitensis Arriaga-Hernández, – Comment 1/37992 2/37993 ZMH P-18947 P-18948 – – Hernández-Alcántara, & Solís-Weiss, 2013 Was described shortly before the completion of this dissertation P. drachi Laubier & Ramos, 1974 H MNHN Poly Type 1266 P. eliasoni Mackie, 1991 H ZMU 291a P(6) 291b 199 TABLE 3.1 (continued) P. forticirrata (Strelzov, 1973) H ZIN P(3) 1/37995 3/37995 P. harpagonea (Storch, 1967) – – – Holotype lost P. hirsuta Sardá, Gil, Taboada & Gili, – – – Holotype mounted on 2009 SEM stub P. ilvana Castelli, 1985 H UP P/0433 P. juvenalis H ZMH P-14858 (Hartmann-Schröder, 1974) P(4) P. lyra (Southern, 1914) S(3) P-14859 NMI 1914.313.1-2 1914.324.1 P. lyra capensis (Day, 1955) S(9) BMNH 1961.16.37-45 P. lyra guadalupensis (Amoureux, 1985) – – – Holotype lost (?) P. magdalenaensis (de León-González, H UANL 6325 Holotype damaged Hernández-Guevara & (indeterminable) Rodríguez-Valencia, 2006) P. mikeli Aguirrezabalaga & Gil, 2009 H MNCN P(1) 16.01/11204 16.01/11205 P. nipponica (Imajima, 1973) H NSMT Pol. H 99 P. perdidoensis (McLelland & Gaston, P(13) USNM 168091 P. perkinsi (McLelland & Gaston, 1994) P(2) USNM 168104 P. spinifera (Hobson, 1972) P(16) USNM 48061 P. strelzovi de León-González & H UANL 6333 Díaz-Castañeda, 2011 P(4) ZMH P-25935 1994) Type specimens of Periquesta canariensis Brito & Núñez, 2002 (Levinsenia canariensis, according to Giere et al. (2007)) and its sister species Levinsenia hawaiiensis Giere, Ebbe & Erséus, 2007, were examined. The synonymy of Periquesta Brito & Núñez, 2002 with Levinsenia, as suggested by Giere et al. (2007), is rejected. In contrast to Levinsenia, both species lack the prostomial terminal organ, they lack saber chaetae, and they possess three, rather than two anal cirri. Furthermore, both species do not belong to Paraonidae because their 200 prostomium and peristomium are not fused, they lack notopodial postchaetal lobes, they possess crochet-like chaetae, and their chaetae are arranged in a single row. Thus, these two species were not considered in the character coding of Levinsenia. The generic affiliation of the species Paradoneis drachi and Paradoneis spinifera was considered doubtful because they lack bifurcate notochaetae. Therefore, they were not considered in the character coding of the genus Paradoneis for the cladistics analysis of the paraonid genera. However, they were included in the cladistics analysis of the Cirrophorus – Paradoneis species complex. The character coding of the genus Paraonis is based on the species Paraonis fulgens (Levinsen, 1884) and P. strelzovi Hartmann-Schröder, 1980. The other species of the genus that I examined were Paraonis dubia Augener (1914), which belongs to the family Orbiniidae, and P. pygoengmatica, Jones, 1968, whose generic affiliation is doubtful. Cirrophorus americanus Strelzov, 1973 was transferred to Paradoneis (prior to the cladistic analysis) because the holotype does not have a prostomial antenna. Strelzov argued that larger (non-type) specimens do possess a prostomial antenna. In my opinion, they belong to a different species because there are several differences in the morphology between the holotype and the non-type specimens with antenna. Cirrophorus brevicirratus Strelzov, 1973 was transferred to Paradoneis (prior to the analysis) because the “microscopic, blister-like protrusion”, which Strelzov found in the largest specimens and interpreted as prostomial antenna, was not observed. Additionally, all species that lack a prostomial antenna but that were described in Cirrophorus were transferred to Paradoneis (prior to the analysis). 201 D) Phylogeny of Paraonidae a) Taxa included Ten paraonid terminal taxa were included in the cladistic analysis of the family: the genera Cirrophorus, Levinsenia, Paradoneis, Paraonides, Paraonis, and Sabidius, and the genus Aricidea, split into its four subgenera Acmira, Aedicira, Allia, and Aricidea. Three outgroup taxa were chosen among the morphologically most similar families, Cossuridae, Orbiniidae, and Questidae. The latter one may belong to Orbiniidae, according to cladistic analyses based on molecular markers (Bleidorn et al. 2009). The genera Cossura and Questa were obvious choices as representatives of their families because they were the only valid genera of Cossuridae (Read 2000) and Questidae (Giere & Erséus 1998, Giere et al. 2007), respectively. The choice of Scoloplos (Scoloplos) as representative of Orbiniidae was arbitrary. b) Characters used for cladistic analysis Twenty-seven characters were used in the cladistic analysis of the paraonid genera, fifteen of which were autapomorphic. Characters and character states are listed below. The data matrix for the analysis is provided in Table 3.2. [1] Apical sensory organ: 0 = absent; 1 = present. The exact function of this retractable papilla, located in the apical prostomium of Levinsenia, is unknown; it may serve as a chemical and/or tactile sensory organ. [2] Prostomial lobes: 0 = absent; 1 = present. Paraonids, cossurids, orbiniids, and questids usually have a simple prostomium. The paraonid genus Sabidius, however, has a prostomium with five conspicuous lobes. [3] Prostomial antenna: 0 = absent; 1 = present. 202 Some paraonid genera bear a single median antenna on their prostomium. Cossurids, orbiniids, and questids all lack prostomial appendages. [4] Peristomial ring: 0 = absent; 1 = present. In Paraonidae, prostomium and peristomium are fused. The outgroup taxa have a clearly separated peristomium that is visible as peristomial ring, resembling a true segment. [5] Dorsal tentacle: 0 = absent; 1 = present. A long threadlike appendage is the most characteristic feature of the family Cossuridae. [6] Dorsal fold: 0 = absent; 1 = present. The dorsal fold with a median slit is the most characteristic feature of the genus Questa. It is part of the male genital structure. [7] Branchiae. 0 = absent; 1 = present. Paired dorsal branchiae are found in Questa, Scoloplos, and all paraonid genera. However, a few paraonid species lack branchiae. [8] Notopodial postchaetal lobes: 0 = absent; 1 = present. Notopodial postchaetal lobes are commonly found in paraonids and orbiniids. Their length between different species and different body regions varies. [9] Length increase of notopodial postchaetal lobes in pre-anal segments: 0 = absent; 1 = present. In some paraonid genera the length of notopodial postchaetal lobes conspicuously increases in the posteriormost segments. [10] Neuropodial lobes. 0 = absent; 1 = present. 203 Chaetae usually emerge from the body wall or vestigial humps in paraonids, cossurids, questids and most other polychaetes belonging to Scolecida sensu Rouse & Fauchald (1997). Some orbiniids, including Scoloplos, have well developed abdominal neuropodia. [11] Position of anus: 0 = terminal; 1 = dorsal. The outgroup taxa all have a terminal anus. The paraonid anus is located dorsally in the pygidium. [12] Number of anal cirri. 0 = two anal cirri; 1 = three anal cirri; 2 = four anal cirri. The number of anal cirri in Scoloplos and Questa varies from species to species. They have either one or two pairs. Paraonidae generally have three anal cirri, two lateral ones and a single median one. The exception is Levinsenia, which lacks the median anal cirrus. [13] Notopodial acicula: 0 = absent; 1 = present. Notopodial acicula are known from Scoloplos and other orbiniid genera. In Paraonidae and the other outgroup taxa they are always absent. [14] Neuropodial acicula: 0 = absent; 1 = present. Neuropodial acicula are known from Scoloplos and other orbiniid genera. In Paraonidae and the other outgroup taxa they are always absent. [15] First chaetiger: 0 = uniramous; 1 = biramous. The first chaetiger in Cossura is uniramous. In the other taxa the first chaetiger is biramous. [16] Crenulate capillary chaetae: 0 = absent; 1 = present. Crenulate capillaries are typical for Orbiniidae and are also found in Questa. They are usually present in all segments. [17] Notopodial crochets: 0 = absent; 1 = present. 204 In addition to capillary chaetae, Questa species have crochet shaped notochaetae. In most Questa species they are present in all segments. [18] Notopodial bifurcate chaetae: 0 = absent; 1 = present. In addition to capillary chaetae, Cirrophorus, Paradoneis, and most species of Scoloplos have bifurcate notochaetae. This includes lyrate, acicular, and harpoon-shaped bifurcate chaetae. In Cirrophorus and Paradoneis the bifurcate chaetae are present in all but a few anterior segments. In Scoloplos, if present, they appear in a more posterior segment. [19] Notopodial tri-, or multifurcated chaetae: 0 = absent; 1 = present. In addition to capillary chaetae, Questa has forked notochaetae with three or four tines. [20] Neuropodial crenulate acicular chaetae: 0 = absent; 1 = present. All species of Scoloplos have sturdy, slightly crenulated, acicular neurochaetae in anterior segments. They are usually accompanied by slender capillary chaetae. [21] Neuropodial hooks. 0 = absent; 1 = present. In addition to capillary chaetae, several paraonid genera have neuropodial hooks in postbranchial segments. [22] Neuropodial pseudocompound chaetae. 0 = absent; 1 = present. In addition to capillary chaetae, Aricidea (sensu stricto) species have pseudocompound neurochaetae in postbranchial segments. [23] Neuropodial mucronate chaetae. 0 = absent; 1 = present. In addition to capillary chaetae, Allia species have mucronate neurochaetae in postbranchial segments. [24] Neuropodial saber chaetae. 0 = absent; 1 = present. 205 In addition to capillary chaetae, Levinsenia species have neuropodial saber chaetae in postbranchial segments. [25] Neuropodial crochets. 0 = absent; 1 = present. In addition to capillary chaetae, Questa species have crochet shaped neurochaetae. In most Questa species they are present in all segments. [26] Position of modified chaetae within parapodia. 0 = in anterior row; 1 = in same row; 2 = in posterior row. In Paraonidae chaetae are arranged in multiple rows. The modified chaetae can be restricted to either the anterior or posterior row. [27] Width change of capillary chaetae. 0 = absent; 1 = present. Some paraonids have very sturdy capillary chaetae in anterior segments. Their width is gradually decreasing along the body. c) Analysis All characters were treated as non-additive and of equal weight. A maximum parsimony analysis was performed with TNT 1.1 (Goloboff et al. 2008). The dataset was small enough to perform a global search for the most parsimonious trees. A strict consensus tree was generated and its nodal support was calculated with 9999 bootstrap replications. Common synapomorphies and autapomorphies were determined and included in the strict consensus tree. CI, RI, and TL were calculated with (Yeates 1992) and without (Bryant 1995) autapomorphies. 206 TABLE 3.2 Character matrix for the genus level analysis of Paraonidae. x = inapplicable character; ? = unknown. Taxa Characters and character states 207 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Cossura 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 x 0 Questa 0 0 0 1 0 1 1 0 0 0 0 0,2 0 0 1 0 1 0 1 0 0 0 0 0 1 1 0 Scoloplos 0 0 0 1 0 0 1 1 0 1 0 0,2 1 1 1 1 0 0,1 0 1 0 0 0 0 0 1 0 Paraonis 0 0 0 0 0 0 1 1 0 0 1 1 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 Levinsenia 1 0 0 0 0 0 0,1 1 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 Sabidius 0 1 0 0 0 0 1 1 0 0 1 ? 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 Paraonides 0 0 0 0 0 0 0,1 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 x 0 Cirrophorus 0 0 1 0 0 0 1 1 1 0 1 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 Paradoneis 0 0 0 0 0 0 0,1 1 1 0 1 1 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 Acmira 0 0 1 0 0 0 1 1 0 0 1 1 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 Aedicira 0 0 1 0 0 0 1 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 x 1 Allia 0 0 1 0 0 0 0,1 1 0 0 1 1 0 0 1 0 0 0 0 0 0 0 1 0 0 0 1 Aricidea 0 0 1 0 0 0 1 1 0 0 1 1 0 0 1 0 0 0 0 0 0 1 0 0 0 2 1 E) Phylogeny of Cirrophorus and Paradoneis a) Taxa included Each of the 28 species and two subspecies of the Cirrophorus – Paradoneis species complex that have been described were included in the analysis. According to the current taxonomy (Aguirrezabalaga & Gil 2009, Read & Fauchald 2013) prior to this analysis, they were assigned to either Cirrophorus or Paradoneis, based on the presence or absence of a prostomial antenna. This meant that prior to the analysis several species described in Cirrophorus were transferred to Paradoneis (see below). The paraonid genera Paraonides and Levinsenia were included as outgroups. Paraonides nordica Strelzov, 1968 was chosen as representative of Paraonides because it is the type species of the genus. I arbitrarily chose to include Levinsenia flava (Strelzov, 1973) as representative of the genus Levinsenia because the type specimen of Levinsenia gracilis (Tauber, 1879), the type species of Levinsenia, is in poor condition. b) Characters used for cladistics analysis Eighteen characters were used to generate a data matrix (Table 3.3), for the cladistic analysis of the paraonid genera, four of which were autapomorphic. Characters and character states are listed below. [1] Apical sensory organ: 0 = absent; 1 = present. This character is discussed in the genus level analysis (see above). [2] Prostomial antenna: 0 = absent; 1 = present. The prostomial antenna has been the crucial character for the distinction between Cirrophorus (antenna present) and Paradoneis (antenna absent). 208 [3] Number of prebranchial chaetigers: 0 = three chaetigers; 1 = four chaetigers; 2 = five chaetigers; 3 = six chaetigers. Paraonid species have a variable number of anterior chaetigers without branchiae. Within the same species this character is mostly constant. [4] Number of branchiae: 0 = branchiae absent; 1 = one pair; 2 = up to four pairs; 3 = up to six pairs; 4 = up to approximately 30 pairs; 5 = up to >40 pairs. Paraonid species have a variable number of branchiae. In species with up to 6 pairs of branchiae, their number varies very little. In species with more than six pairs, the number varies considerably and usually increases with size of the individual. I included one character state with a broad range, in order to account for the intraspecific variability and to avoid artificially introduced character state changes. [5] Size of anteriormost pair of branchiae: 0 = similar to following branchiae; 1 = conspicuously reduced. In some species the first pair of branchiae is reduced to small tuberculate or conical protrusions. [6] Notopodial postchaetal lobes in prebranchial segments: 0 = absent; 1 = tuberculate/conical; 2 = digitiform/cirriform. Postchaetal lobes may be either entirely absent, short protrusions, or well developed lobes. [7] Notopodial postchaetal lobes in branchial segments: 0 = absent; 1 = tuberculate/conical; 2 = digitiform/cirriform. Postchaetal lobes may be either entirely absent, short protrusions, or well developed lobes. [8] Notopodial postchaetal lobes in postbranchial segments: 0 = absent; 1 = tuberculate/conical; 2 = digitiform/cirriform. Postchaetal lobes may be either entirely absent, short protrusions, or well developed lobes. 209 [9] Conspicuous length increase in notopodial postchaetal lobes in pre-anal segments: 0 = absent; 1 = present. In all species of Cirrophorus, Paradoneis, and Paraonides the notopodial postchaetal lobes in pre-anal segments are conspicuously elongated. [10] Number of anal cirri: 0 = two anal cirri; 1 = three anal cirri. Levinsenia has two anal cirri; the remaining paraonid genera have three anal cirri. [11] Notochaetal spines: 0 = absent; 1 = present. Two species described in Paradoneis, P. drachi Laubier & Ramos, 1974 and P. spinifera (Hobson, 1972), have notochaetal spines, rather than the typical bifurcate notochaetae. The spines occur only in posterior chaetigers and are accompanied by simple capillary chaetae. [12] Notochaetal bifurcate chaetae: 0 = absent; 1 = lyrate; 2 = acicular; 3 = harpoon-shaped. Most species of Cirrophorus and Paradoneis have bifurcate notochaetae, in addition to simple capillary notochaetae. Lyrate chaetae have two tines with similar width (Fig. 3.1A); acicular bifurcate chaetae have one very sturdy and one very thin tine (Fig. 3.1B); harpoon-like chaetae are similar to the acicular type, but they have a subterminal bulge (Fig. 3.1C). [13] Shape transition of bifurcate notochaetae: 0 = absent; 1 = present. Most species with acicular and harpoon-like bifurcate notochaetae have lyrate chaetae in anterior chaetigers. The shape of the chaetae then gradually changes along the body. The ventral tine gets more and more sturdy and the dorsal tine more and more vestigial. In a few species the bifurcate chaetae are acicular throughout. [14] Maximum number of bifurcate chaetae per segment: 0 = one chaeta; 1 = two chaetae; 2 = three chaetae; 3 = four chaetae; 4 = five chaetae; 5 = six chaetae; 6 = seven chaetae; 7 = eight chaetae. 210 The number of bifurcate notochaetae per notopodial fascicle usually varies along the body. The maximum number is usually found in the median and posterior branchial and the anterior postbranchial body regions. [15] Starting chaetiger of bifurcate chaetae: 0 = chaetiger one; 1 = chaetiger two; 2 = chaetiger three; 3 = chaetiger four; 4 = chaetiger five; 5 = chaetiger six; 6 = chaetiger seven; 7 = chaetiger eight; 8 = chaetiger nine; 9 = chaetiger ten; 10 = chaetiger eleven. In most species the first segment with bifurcate chaetae is constant or varies only slightly. [16] Position of notochaetal spines within fascicle: 0 = dorsal; 1 = ventral. The notochaetal spines are in dorsal position in P. spinifera and in ventral position in P. drachi, relative to the regular capillary notochaetae. [17] Neuropodial saber chaetae: 0 = absent; 1 = present. This character is discussed in the genus level analysis (see above). [18] Neuropodial spines: 0 = absent; 1 = present. Several species of the Cirrophorus – Paradoneis species complex have neuropodial spines in posterior chaetigers. c) Analysis Character [12] was treated as additive because there is a clear transition in the shape of the bifurcate chaetae (see above). The transition from character state zero to one (development of lyrate chaetae), a synapomorphy of the clade (Cirrophorus, Paradoneis) was scored with a weight of two, the transitional shape changes from lyrate to acicular and from acicular to harpoon-shaped were each scored with a weight of one. The remaining characters were treated as non-additive. Character state changes in characters [1], [9], [10], and [17] that include 211 TABLE 3.3 Character matrix for the species level analysis of the genera Cirrophorus and Paradoneis. x = inapplicable character; ? = unknown. Taxa Characters and character states 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 Levinsenia flava 1 0 2 2 0 1 2 1 0 0 0 0 x x x x 1 0 Paraonides nordica 0 0 1 3 0 1 1 1 1 1 0 0 x x x x 0 0 C. aciculatus 0 1 1 4 0 1 2 1 1 1 0 2 1 3 5 x 0 0 C. branchiatus 0 1 1 4 0 1 2 1 1 1 0 2 1 2 4 x 0 0 C. furcatus 0 1 0 4 1 1 2 1 1 1 0 1 1 2 2 x 0 0 C. longifurcatus 0 1 0 4 0 1 2 1 1 1 0 1 1 1 7 x 0 0 C. lyriformis 0 1 1 4 1 1 2 1 1 1 0 2 1 3 5 x 0 0 C. miyakoensis 0 1 0 5 0 2 2 2 1 1 0 1 1 3 10 x 0 0 P. abranchiata 0 0 x 0 x 1 1 1 1 1 0 1 1 4 6 x 0 0 P. americana 0 0 0 4 0 1 2 2 1 1 0 1 1 1 1 x 0 1 P. armata 0 0 0 4 0 1 2 1 1 1 0 3 1 3 2-9 x 0 0 212 01 TABLE 3.3 (continued) Taxa Characters and character states 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 P. bathyilvana 0 0 1 4 0 1 1 1 1 1 0 1 1 2 4 x 0 0 P. brevicirrata 0 0 0 4 0 1 1 1 1 1 0 1 1 3,4 5 x 0 0 P. brunnea 0 0 0 4 0 1 2 1 1 1 0 1 1 3 2 x 0 0 P. carmalitensis 0 0 0 4 0 1 2 1 1 1 0 1 1 1 3 x 0 0 P. drachi 0 0 3 4 0 1 2 1 1 1 1 0 x x x 1 0 0 P. eliasoni 0 0 0 4 0 1 2 2 1 1 0 1 1 2 3-7 x 0 1 P. forticirrata 0 0 0 4 1 1 2 2 1 1 0 1 1 4-7 3-5 x 0 0 P. harpagonea 0 0 0 4 0 ? ? ? 1 1 0 3 1 1 2 x 0 0 P. hirsuta 0 0 1 4 0 1 2 2 1 1 0 1 1 2 11 x 0 0 P. ilvana 0 0 0 4 0 0 0 0 1 1 0 1 1 2 4-7 x 0 0 P. juvenalis 0 0 0 1 x 0 0 0 1 1 0 2 0 0,1 3 x 0 0 213 01 TABLE 3.3 (continued) Characters and character states 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 P. lyra 0 0 0 4 0 1 2 1 1 1 0 1 1 2,3 0-5 x 0 0 P. lyra capensis 0 0 0 4 0 0 0 1 1 1 0 1 1 2 2-3 x 0 0 P. lyra guadalupensis 0 0 0 4 0 1 2 2 1 1 0 1 1 3 2 x 0 0 P. magdalenaensis 0 0 1 4 0 1 2 1 1 1 0 2 0 1 5 x 0 0 P. mikeli 0 0 1 4 0 1 2 1 1 1 0 1 1 3 3-5 x 0 0 P. nipponica 0 0 0 4 0 1 2 1 1 1 0 1 1 3 1 x 0 0 P. perdidoensis 0 0 0 2 0 0,1 1 1 1 1 0 1 1 0 2 x 0 0 P. perkinsi 0 0 0 2 0 0 0 0 1 1 0 2 0 0 1 x 0 0 P. spinifera 0 0 1,2 4 1 1 2 1 1 1 1 0 x x x 0 0 0 P. strelzovi 0 0 0 4 0 1 2 2 1 1 0 1 1 3 3 x 0 1 214 Taxa synapomorphies of the clade (Paraonides (Cirrophorus, Paradoneis)) and autapomorphies of the outgroup Levinsenia flava (according to the genus level cladistic analysis, see below) were scored with a weight of two. Additionally, changes in character [2], the presence of a prostomial antenna was scored with a weight of two, for two reasons. First, the prostomial antenna has been considered to be such an important character by the majority of taxonomists (see above) that is has been used as the single character to distinguish the genera Cirrophorus and Paradoneis. And second, for testing the null hypothesis that Cirrophorus and Paradoneis are monophyletic genera, I preferred to take a conservative stance. All remaining characters were scored with a weight of one. A Maximum Parsimony analysis was performed with TNT 1.1 (Goloboff et al. 2008). I performed a heuristic search with tree bisection reconnection (TBR) algorithm, one random seed, 1000 replicates of random taxon additions, and 10 trees saved per replication. A strict consensus tree was generated and its nodal support was calculated with 999 bootstrap replications. A majority rule tree with common synapomorphies was generated. CI, RI, and TL were calculated with (Yeates 1992) and without (Bryant 1995) autapomorphies. Results A) Cladistic analysis of the family Paraonidae The maximum parsimony analysis of the family Paraonidae resulted in seven equally parsimonious cladograms. Tree length, consistency index, and retention index including autapomorphies were TL = 35, CI = 0.86, and RI = 0.77. When autapomorphies were excluded these values were TL = 20, CI = 0.75, and RI = 0.77. Paraonidae was recovered in all of them as 215 monophyletic and supported by a bootstrap value of 61 (Fig. 3.2). Synapomorphies of Paraonidae include the unusual dorsal position of the anus and the absence of a clearly distinguishable peristomial ring because of the fusion between prostomium and peristomium. Within Paraonidae the clade (Paraonides (Cirrophorus, Paradoneis)) was recovered, albeit bootstrap support of both nodes was weak (bootstrap values of 50). Common synapomorphy of the clade is the conspicuous elongation of notopodial postchaetal lobes in preanal segments. Common synapomorphy of the clade (Cirrophorus, Paradoneis) is the development of bifurcate chaetae. FIGURE 3.2 Strict consensus tree of the seven most parsimonious cladograms for paraonid genera. Common synapomorphies and autapomorphies are shown above nodes and terminal branches, respectively. Homoplastic characters are in brackets. Bootstrap support values are shown below nodes. 216 The synapomorphies of the four subgenera of Aricidea are presence of a prostomial antenna and sturdy capillary chaetae in the anterior body. The prostomial antenna is a homoplastic character because it is also occurs as an autapomorphy in the genus Cirrophorus (Fig. 3.2). The remaining phylogenetic relationships among paraonid genera could not be resolved. The tree was rooted with Scoloplos as the outgroup, which resulted in a polytomy of Cossura, Questa, and Paraonidae (Fig. 3.2). The tree was also rooted with Cossura as the outgroup (not shown). In this case (Scoloplos, Questa) was recovered as the sister clade of Paraonidae with a bootstrap support of 52. B) Cladistic analysis of the genera Cirrophorus and Paradoneis The maximum parsimony analysis of the Cirrophorus – Paradoneis species complex resulted in 1337 equally parsimonious cladograms. Tree length, consistency index, and retention index including autapomorphies were TL = 73, CI = 0.62, and RI = 0.67). When autapomorphies were excluded these values were TL = 65, CI = 0.57, and RI = 0.67. A clade consisting of Paraonides nordica and all Cirrophorus and Paradoneis species was recovered in all of the most parsimonious trees and supported with a bootstrap value of 100 (Fig. 3.3). This clade was polytomic, including Paraonides nordica, a clade consisting of Paradoneis drachi and P. spinifera, and a clade consisting of all other Cirrophorus and Paradoneis species. The latter two clades were supported with bootstrap values of 55 and 50, respectively (Fig. 3.3). The synapomorphy of the clade consisting of P. drachi and P. spinifera is the development of notopodial spines in posterior chaetigers. The synapomorphy of the clade of 217 the remaining 28 species and subspecies of Cirrophorus and Paradoneis is the development of bifurcate notochaetae. Within the clade of species with bifurcate chaetae, only three other clades were recovered in all of the most parsimonious trees. The first one consists of Cirrophorus aciculatus (Hartman, 1957), C. branchiatus Ehlers, 1908, and C. lyriformis, which share a prostomial FIGURE 3.3 Strict consensus tree of 1337 most parsimonious cladograms of Cirrophorus and Paradoneis species. Bootstrap support values are shown next to nodes. 218 antenna and acicular bifurcate notochaetae as synapomorphies. This clade is supported with a weak bootstrap value of 18. Second, a clade consisting of Paradoneis armata and P. harpagonea (Storch, 1967) was supported with a bootstrap value of 45. The synapomorphy of the clade is the development of harpoon-shaped bifurcate notochaetae. Third, a clade consisting of P. juvenalis (Hartmann-Schröder, 1974) and P. perkinsi McLelland & Gaston, 1994 was supported with a bootstrap value of 66. These two species share the synapomorphies of reduced notopodial postchaetal lobes in all but the last few pre-anal segments, the development of acicular bifurcate notochaetae, and the absence of lyrate bifurcate notochaetae in anterior chaetigers. The remaining topography of the phylogenetic tree was inconsistent among the most parsimonious trees and is therefore unresolved in the strict consensus tree. Because of the low resolution of phylogenetic relationships in the strict consensus tree, a majority consensus rule tree was generated (Fig. 3.4). In this tree six clades were recovered among the Cirrophorus and Paradoneis species with bifurcate notochaetae. The clade (P. armata, P. harpagonea) was the same as in the strict consensus tree. The clade (P. magdalenaensis (C. branchiatus (C. aciculatus, C. lyriformis))) contains species with bifurcate acicular chaetae and well developed notopodial postchaetal lobes in branchial chaetigers. It was recovered in 91% of the most parsimonious trees. The three remaining species of Cirrophorus with only lyrate chaetae, C. furcatus (Hartman, 1957), C. longifurcatus Hartmann-Schröder, 1965, and C. miyakoensis Imajima, 1973, form a polytomic clade, which was recovered in 77% of the most parsimonious trees. The clade (P. lyra capensis (P. ilvana (P. juvenalis, P. perkinsi))) contains all of the species with strongly reduced notopodial postchaetal lobes. The clade was recovered in 66% of the most parsimonious trees. Species of the clade (P. ilvana (P. juvenalis, P. perkinsi)), which 219 220 FIGURE 3.4 Majority rule consensus tree of 1337 most parsimonious cladograms of Cirrophorus and Paradoneis species. The percentages of trees supporting a clade are shown next to the node. The orange, purple, and grey fields represent three different genera Paraonides, Gen. nov., and Cirrophorus, respectively. The green, blue, brown, pink, turquoise, and yellow fields within the grey field represent clades within Cirrophorus that are supported by the majority of the most parsimonious cladograms. Common synapomorphies are indicated. was recovered in 66% of the most parsimonious trees, lack notopodial postchaetal lobes altogether, except in their posteriormost pre-anal segment. P. lyra capensis (Day, 1955) has tuberculate notopodial postchaetal lobes in postbranchial chaetigers. The polytomic clade (P. americana, P. eliasoni, P. strelzovi) consists of species that have developed neuropodial spines in posterior segments. It was recovered in 94% of the most parsimonious trees. The clade (P. abranchiata, P. brevicirrata) was recovered in 70% of the most parsimonious trees. Both species have in common notopodial postchaetal lobes that are small tuberculate protrusions throughout. The phylogenetic relationships of the remaining ten taxa could not be resolved (Fig. 3.4). Discussion A) Cladistic analysis of the family Paraonidae The hypothesis that the family Paraonidae is monophyletic was confirmed. Synapomorphies of the family are the fused prostomium and peristomium and the dorsal location of the anus. The genus Periquesta, which, does not belong to Paraonidae, has a dorsally located anus, too. The phylogenetic affiliation of this genus needs to be addressed in future studies. The genus Paraonides is the sister taxon of the clade (Cirrophorus, Paradoneis). The genera share the conspicuous elongation of the notopodial postchaetal lobes in pre-anal segments. The development of bifurcate chaetae is an apomorphy of the Cirrophorus and Paradoneis species complex. 221 The genus Aricidea was recovered as monophyletic. However, the more disputed question of whether the subgenera are monophyletic will be addressed in a separate manuscript (Reuscher in prep.). Phylogenetic relationships among the paraonid genera were only poorly resolved because Paraonidae are simplistic polychaetes with only a small number of morphological characters. Therefore, the addition of ultrastructural characters or molecular markers is needed in order to yield a better phylogenetic resolution. B) Cladistic analysis of the genera Cirrophorus and Paradoneis Three sister clades that share the synapomorphy of elongated notopodial postchaetal lobes in pre-anal segments were recovered in the analysis. One clade includes all Cirrophorus species and the majority (22 of 24) of Paradoneis species and subspecies. These species all have developed bifurcate notochaetae that commence in one of the anterior segments and continue to the end of the body. A second clade includes the two remaining Paradoneis species, P. drachi and P. spinifera. These species have developed spines in posterior notopodial fascicles, but lack the typical bifurcate notochaetae. The third sister taxon was Paraonides nordica, the representative of the outgroup taxon Paraonides. Because Paraonidae are polychaetes with a simple external morphology and few characters useful for cladistic analyses may be the reasons for the large number of most parsimonious trees and the low resolution of phylogenetic relationships. This problem may be alleviated with the inclusion of ultrastructural examinations and molecular markers in future studies. 222 The majority rule tree has a slightly better phylogenetic resolution and recovered six clades within the large clade of the Cirrophorus and Paradoneis species with bifurcate notochaetae. Within the clade (P. magdalenaensis (C. branchiatus (C. armatus, C. lyriformis))) the development of a prostomial antenna is a synapomorphy of the clade (C. branchiatus (C. armatus, C. lyriformis)). Another clade, (C. furcatus, C. longifurcatus, C. miyakoensis), also shares the synapomorphy of a prostomial antenna. Thus, the prostomial antenna seems to be a homoplastic character, that has not only developed independently in the genera Aricidea and Cirrophorus (see above) but also twice within the Cirrophorus – Paradoneis clade. Therefore, the second hypothesis, that Cirrophorus is monophyletic, is rejected. Cirrophorus is considered polyphyletic and Paradoneis is considered paraphyletic. The genus Paradoneis should be considered a junior synonym of Cirrophorus. The development of acicular chaetae in P. juvenalis and P. perkinsi, both of which belong to a clade of species with strongly reduced notopodial postchaetal lobes, suggests that this character is also homoplastic. The absence of notopodial postchaetal lobes in prebranchial and branchial chaetigers of P. lyra capensis is in contrast to the well-developed lobes in (P. lyra Southern, 1914). Therefore, I recommend the elevation of this subspecies to species status (see Table 3.4). Paradoneis drachi and P. spinifera are classified in a new genus. The new genus is not named here because the name would become a nomen nudum, according to the International Code of the Zoological Nomenclature. Therefore, it is simply referred to as Gen. nov. 223 TABLE 3.4 Recommended taxonomic classification of the Cirrophorus – Paradoneis species complex, in comparison to the previous taxonomic classification (sensu Hartman 1965 and Katzmann & Laubier 1975). Recommended classification Previous classification Original description Cirrophorus abranchiatus Paradoneis abranchiata Paradoneis abranchiata Cirrophorus aciculatus Cirrophorus aciculatus Aricidea (Cirrophorus) aciculata Cirrophorus americanus Paradoneis americana Cirrophorus americanus Cirrophorus armatus Paradoneis armata Paradoneis armata Cirrophorus bathyilvana Paradoneis bathyilvana Paradoneis bathyilvana Cirrophorus branchiatus Cirrophorus branchiatus Cirrophorus branchiatus Cirrophorus brevicirratus Paradoneis brevicirrata Cirrophorus brevicirratus Cirrophorus brunneus Paradoneis brunnea Cirrophorus brunneus Cirrophorus capensis Paradoneis lyra capensis Paraonis (Paraonides) lyra capensis Cirrophorus carmalitensis Paradoneis carmalitensis Paradoneis carmalitensis Cirrophorus eliasoni Paradoneis eliasoni Paradoneis eliasoni Cirrophorus forticirratus Paradoneis forticirrata Cirrophorus forticirratus Cirrophorus furcatus Cirrophorus furcatus Aricidea (Cirrophorus) furcata Cirrophorus harpagoneus Paradoneis harpagonea Paraonis (Paraonides) harpagonea Cirrophorus hirsutus Paradoneis hirsuta Paradoneis hirsuta Cirrophorus ilvana Paradoneis ilvana Paradoneis ilvana Cirrophorus juvenalis Paradoneis juvenalis Paraonis (Paradoneis) juvenalis Cirrophorus longifurcatus Cirrophorus longifurcatus Aricidea (Cirrophorus) longifurcata Cirrophorus lyra Paradoneis lyra Paraonis (Paraonides) lyra Cirrophorus lyra guadalupensis Paradoneis lyra guadalupensis Cirrophorus lyra guadalupensis Cirrophorus lyriformis Cirrophorus lyriformis Paraonis (Paraonides) lyriformis Cirrophorus magdalenaensis Paradoneis magdalenaensis Cirrophorus magdalenaensis Cirrophorus mikeli Paradoneis mikeli Paradoneis mikeli Cirrophorus miyakoensis Cirrophorus miyakoensis Cirrophorus miyakoensis Cirrophorus nipponicus Paradoneis nipponica Paraonides nipponica Cirrophorus perdidoensis Paradoneis perdidoensis Cirrophorus perdidoensis Cirrophorus perkinsi Paradoneis perkinsi Cirrophorus perkinsi Cirrophorus strelzovi Paradoneis strelzovi Paradoneis strelzovi Gen. nov. drachi Paradoneis drachi Paradoneis drachi Gen. nov. spinifera Paradoneis spinifera Paraonis spinifera Cirrophorus Gen. nov. 224 Conclusion The most important conclusions from this study:     The family Paraonidae is monophyletic. The genus Cirrophorus is polyphyletic. The genus Paradoneis is paraphyletic. The genera Cirrophorus and Paradoneis will be synonymized, with Cirrophorus being the senior synonym and Paradoneis being the junior synonym.  The species Paradoneis drachi and P. spinifera will be classified in a new genus. P. spinifera, which was described earlier, will be the type species of the new genus.   The genera Paraonides, Gen. nov., and Cirrophorus are sister genera. For a better resolution of the phylogeny of paraonid genera and species of Cirrophorus, the limited number of morphological characters should be supplemented with the use of molecular markers or ultrastructural characters in future studies. The newly proposed taxonomic classification of all Cirrophorus and Paradoneis species is presented in Table 3.4. Acknowledgements The following persons are sincerely thanked for their help and support during my visits to museum collections: Kristian Fauchald, Linda Ward, William Moser, Karen Reed, Chad Walter, Geoff Keel, Cheryl Bright, Katie Ahlfeld, Paul Greenhall (National Museum of Natural History, Smithsonian Institution in Washington, D.C.), Kirk Fitzhugh, Leslie Harris (Natural History Museum of Los Angeles County), Sergey Gagaev, Vladislav Potin (Zoological Institute, Russian 225 Academy of Sciences in St. Petersburg, Russia), Angelika Brandt, Katrin Philipps-Bussau, Cornelia Warneke-Cremer (Zoologisches Museum in Hamburg, Germany), and Karin Meißner (Deutsches Zentrum für Marine Biodiversitätsforschung in Hamburg, Germany). Leslie Harris is also sincerely thanked for generously hosting me in her house during my stay in Los Angeles, and her hospitality. Kristian Fauchald is thanked for providing funding for my travel to the National Museum of Natural History, Smithsonian Institution in Washington, D.C. Travels to Hamburg, and St. Petersburg were funded by the Harte Research Institute for Gulf of Mexico Studies and the Ernst Mayr Travel Grant for Animal Systematics from the Museum of Comparative Zoology, Harvard University. I am indebted to Minoru Imajima and Hironori Komatsu (National Museum of Nature and Science in Tsukuba, Japan), Emma Sherlock (The Natural History Museum in London, United Kingdom), Tarik Meziane (Muséum National d’Histoire Naturelle in Paris, France), Javier Ignazio Sánchez Almazán (Museo Nacional de Ciencias Naturales in Madrid, Spain), Karen Osborn and William Moser (National Museum of Natural History, Smithsonian Institution in Washington, D.C), Birger Neuhaus (Museum für Naturkunde in Berlin, Germany), Jesús Angel de León González (Universidad Autónoma de Nuevo León in San Nicolás de Los Garza, Mexico), Erica Sjöllin (Evolutionmuseet in Uppsala, Sweden), Alberto Castelli (Universitá di Pisa, Italy), and Nigel Monaghan (National Museum of Ireland in Dublin, Ireland) for their loans of type specimens. Costs for shipments of type specimens were covered by the Flavius and Kathy Killebrew Dean’s Annual Scholarship, awarded by the College of Science & Engineering, Texas A&M University – Corpus Christi. Discussions with Kristian Fauchald, João Gil (Centre d'Estudis Avançats de Blanes, Spain), and Larry Lovell (County Sanitation Districts of Los Angeles County in Carson, California) about the morphology and taxonomy of Paraonidae and with Kirk Fitzhugh about character coding for 226 cladistic analyses were very helpful. The College of Science and Engineering at Texas A&M University – Corpus Christi is thanked for providing teaching assistantships between fall semester 2008 and spring semester 2011. Paul Montagna is thanked for his support through a research assistantship beginning in the fall semester of 2011 and provision of lab space, including the use of microscopes. Financial support during the summer semesters of 20010-2013 was provided through MARB scholarships by the College of Science & Engineering at Texas A&M University – Corpus Christi. The Willi Hennig Society is thanked for making the analytical package TNT freely available. References Aguirrezabalaga, F. & Gil, J. (2009) Paraonidae (Polychaeta) from the Capbreton Canyon (Bay of Biscay, NE Atlantic) with the description of eight new species. Scientia Marina, 73(4), 631-666. Alston, D.E., Cabarcas, A., Capella, J., Benetti, D.D., Keene-Meltzoff, S., Bonilla, J. & Cortés, R. (2005) Environmental and social impact of sustainable offshore cage culture production in Puerto Rican waters. Final Report, 4/4/2005, NOAA Federal Contract Number NA16RG1611. 207 pp. Amoureux, L. (1985) Annélides benthiques récoltées à l’entrée de la lagune de la Manche-à-Eau, Guadeloupe (Antilles). Bulletin du Muséum National d’Histoire Naturelle, 4e série, section A, 7(1), 93-107. Annenkova, N.P. (1934) [Paraonidae of the far eastern seas of the USSR]. Doklady Akademii Nauk SSSR, 2, 153-194 (in Russian). 227 Armstrong, M.P. (1995) A comparative study of the ecology of smooth flounder Pleuronectes americanus, from Great Bay estuary, New Hampshire. Dissertation. University of New Hampshire, Durham, 135 pp. Arriaga-Hernández, S., Hernández-Alcántara, P. & Solís-Weiss, V. (2013) Description and distribution of two new species of Paraonidae (Annelida: Polychaeta) from a lagoonestuarine ecosystem in the Southern Gulf of Mexico. Zootaxa, 3686(1), 51-64. Augener, H. 1914. Polychaeta II: Sedentaria. In: Michaelsen, W. & Hartmeyer, R. (Eds.). Die Fauna Südwest-Australiens. Ergebnisse der Hamburger südwest-australischen Forschungsreise l905. Volume 5. Gustav Fischer Verlag, Jena, pp. 1-72. Bautista-Vega, A.A, Letourneur, Y., Harmelin-Vivien, M. & Salen-Picard, C. (2008) Difference in diet and size-related trophic level in two sympatric fish species, the red mullets Mullus barbatus and Mullus surmuletus, in the Gulf of Lions (north-west Mediterranean Sea). Journal of Fish Biology, 73(10), 2402-2420. Blake, J.A., Grassle, J.F., Maciolek-Blake, N., Neff, J.M. & Sanders, H.L. (1983) The Georges Bank benthic infauna monitoring program. Final report, first year of sampling (July, 1981 – May, 1982). United States Department of the Interior, Minerals Management Service, Washington D.C. Contract No. 14-12-0001-29192, 154 pp. Bleidorn, C., Hill, N., Erséus, C. & Tiedemann, R. (2009) On the role of character loss in orbiniid phylogeny (Annelida): molecules vs. morphology. Molecular Phylogenetics and Evolution, 52(1), 57-69. 228 Brito, M.C., Martin, D. & Núñez, J. (2005) Polychaetes associated to a Cymodocea nodosa meadow in the Canary Islands: assemblage structure, temporal variability and vertical distribution compared to other Mediterranean seagrass meadows. Marine Biology, 146(3), 467-481. Brito, M.C. & Núñez, J. (2002) A new genus and species of Questidae (Annelida: Polychaeta) from the central Macaronesian region and a cladistic analysis of the family. Sarsia, 87(4), 281-289. Bryant, H.N. (1995) Why autapomorphies should be removed: a reply to Yeates. Cladistics, 11(4), 381-384. Carus, J.V. (1863) Vermes. In: Peters, W.C.H., Carus, J.V. & Gerstäcker, C.E.A. (Eds.) Handbuch der Zoologie. Wilhelm Engelmann, Leipzig, pp. 422-484. Castelli, A. (1985) Paraonidae (Annelida, Polychaeta) des fonds meubles infralittoraux des côtes toscanes. Cahiers de Biologie Marine, 26(3), 267-279. Castriota, L., Scarabello, M.P., Finoia, M.G., Sinopoli, M. & Andaloro, F. (2005) Food and feeding habits of pearly razorfish, Xyrichtys novacula (Linnaeus, 1758), in the southern Tyrrhenian Sea: variation by sex and size. Environmental Biology of Fishes, 72(2), 123133. Cerruti, A. (1909) Contributo all`Anatomia, biologia e sistematica delle Paraonidae (Levinsenidae) con particolare riguardo alle specie del golfo di Napoli. Mitteilungen aus der Zoologischen Station zu Neapel, 19(3), 459-512. Chainho, P., Costa, J.L., Chaves, M.L., Lane, M.F., Dauer, D.M. & Costa, M.J. (2006) Seasonal and spatial patterns of distribution of subtidal benthic invertebrate communities in the Mondego River, Portugal – a poikilohaline estuary. Hydrobiologia, 555, 59-74. 229 Dauby, P., Scailteur, Y. & De Broyer, C. (2001) Trophic diversity within the eastern Weddell Sea amphipod community. Hydrobiologia, 443(1-3), 69-86. Day, J.H. (1955) The Polychaeta of South Africa. Part 3. Sedentary species from Cape shores and estuaries. Journal of the Linnean Society, London, 42, 407-452. de León-González, J.A. & Diaz-Castañeda, V. (2011) A new species of Paradoneis (Polychaeta: Paraonidae) from the western coast of Baja California, Mexico. Proceedings of the Biological Society of Washington, 124(1), 40-44. de León-González, J.A., Hernández Guevara, N.A. & Rodríguez-Valencia, J.A. (2006) Paraonidae (Polychaeta) from western Mexico, with description of two new species. Journal of the Marine Biological Association of the United Kingdom, 86(2), 253–262. Díaz-Castañeda, V. & Valenzuela-Solano, S. (2009) Polychaete fauna in the vicinity of bluefin tuna sea-cages in Ensenada, Baja California, Mexico. Zoosymposia, 2, 505-526. Ehlers, E. (1908) Die bodensässigen Anneliden aus den Sammlungen der deutschen TiefseeExpedition. In: Chun, C. (Ed.) Wissenschaftliche Ergebnisse der deutschen TiefseeExpedition “Valdivia”, 1898-1899, Band 16. Verlag von Gustav Fischer, Jena, 167 pp. + 23 plates. Fairchild, E.A., Sulikowski, J., Rennels, N., Howell, W.H. & Gurshin, C.W.D. (2008) Distribution of winter flounder, Pseudopleuronectes americanus, in the HamptonSeabrook Estuary, New Hampshire: Observations from a field study. Estuaries and Coasts, 31(6), 1158-1173. Fauchald, K. (1977) The polychaete worms. Definitions and keys to the orders, families and genera. Natural History Museum of Los Angeles County, Science Series, 28, 1-190. 230 Fauchald, K. & Hancock, D.R. (1981) Deep-water polychaetes from a transect off central Oregon. Allan Hancock Foundation Monograph No. 11. Allan Hancock Foundation and the Institute for Marine and Coastal Studies. University of Southern California, Los Angeles, California, 73 pp. Feder, H.M. & Pearson, T.H. (1988) The benthic ecology of Loch Linnhe and Loch Eil, a sealoch system on the west coast of Scotland. V. Biology of the dominant soft-bottom epifauna and their interaction with the infauna. Journal of Experimental Marine Biology and Ecology, 116(2), 99-134. Fiege, D., Ramey, P.A. & Ebbe, B. (2010) Diversity and distributional patterns of Polychaeta in the deep South Atlantic. Deep-Sea Research I, 57(10), 1329-1344. Fujiwara, Y., Kawato, M., Yamamoto, T., Yamanaka, T., Sato-Okoshi, W., Noda, C., Tsuchida, S., Komai, T., Cubelio, S.S., Sasaki, T., Jacobsen, K., Kubokawa, K., Fujikura, K., Maruyama, T., Furushima, Y., Okoshi, K., Miyake, H., Miyazaki, M., Nogi, Y., Yatabe, A. & Okutani, T. (2007) Three-year investigations into sperm whale-fall ecosystems in Japan. Marine Ecology, 28(1), 219-232. Gabriel, W.L. & Pearcy, W.G. (1981) Feeding selectivity of Dover sole, Microstomus pacificus, off Oregon. Fishery Bulletin, 79(4), 749-763. Gaston, G.R, McLelland, J.A., & Heard, R.W. (1992) Feeding biology, distribution, and ecology of two species of benthic polychaetes: Paraonis fulgens and Paraonis pygoenigmatica (Polychaeta: Paraonidae). Gulf Research Reports, 8(4), 395-399. Giere, O., Ebbe, B. & Erséus, C. (2007) Questa (Annelida, Polychaeta, Orbiniidae) from Pacific regions – new species and reassessment of the genus Periquesta. Organisms Diversity & Evolution, 7(4), 304-319. 231 Giere, O. & Erséus, C. (1998) A systematic account of the Questidae (Annelida, Polychaeta), with description of new taxa. Zoologica Scripta, 27(4), 345-360. Glémarec, M. (1966) Paraonidae de Bretagne. Paraonidae de Bretagne. Description de Paradoneis armata nov. sp. Vie et Milieu, série A: Biologie Marine, 17, 1045-1052. Goloboff, P.A., Farris, J.S. & Nixon, K.C. (2008) TNT, a free program for phylogenetic analysis. Cladistics, 24, 774-786. González, P. & Oyarzún, C. (2003) Diet of the Chilean sandperch, Pinguipes chilensis (Perciformes, Pinguipedidae) in southern Chile. Journal of Applied Ichthyology, 19(6), 371-375. Grube, A.-E. (1850) Die Familien der Anneliden. Archiv für Naturgeschichte, Berlin, 16, 249364. Hartley, J.P. (1981) The family Paraonidae (Polychaeta) in British waters: a new species and new records with a key to species. Journal of the Marine Biological Association of the United Kingdom, 61(1), 133-149. Hartman, O. (1957) Orbiniidae, Apistobranchidae, Paraonidae and Longosomidae. Allan Hancock Pacific Expeditions, 15(3), 211-393. Hartman, O. (1965) Deep-water benthic polychaetous annelids off New England to Bermuda and other north Atlantic areas. Allan Hancock Occasional Papers, 28, 1-378. Hartmann-Schröder, G. (1965) Die Polychaeten des Sublitorals. In: Hartmann-Schröder, G. & Hartmann, G. (Eds.) Zur Kenntnis des Sublitorals der chilenischen Küste unter besonderer Berücksichtigung der Polychaeten und Ostracoden. Mitteilungen des Hamburgischen Zoologischen Museums und Instituts, 62, 59-305. 232 Hartmann-Schröder, G. (1974) Zur Polychaetenfauna von Natal (Südafrika). Mitteilungen des Hamburgischen Zoologischen Museums und Instituts, 71, 35-73. Hartmann-Schröder, G. 1980. Die Polychaeten der tropischen Nordwestküste Australiens (zwischen Port Samson im Norden und Exmouth im Süden) In: Hartmann-Schröder, G. & Hartmann, G. (Eds.) Zur Kenntnis des Eulitorals der australischen Küsten unter besonder Berücksichtigung der Polychaeten und Ostracoden. Mitteilungen aus dem Hamburgischen zoologischen Museum und Institut, 77, 41-110. Hartmann-Schröder, G. & Rosenfeldt, P. (1988) Die Polychaeten der “Polarstern”-Reise ANT III/2 in die Antarktis 1984. Teil 1: Euphrosinidae bis Chaetopteridae. Mitteilungen des Hamburgischen Zoologischen Museums und Instituts, 85, 25-72. Hobson, K.D. (1972) Two new species and two new records of the family Paraonidae (Annelida, Polychaeta) from the northeastern Pacific Ocean. Proceedings of the Biological Society of Washington, 85(48), 549-556. Hughes, D.J., Lamont, P.A., Levin, L.A., Packer, M., Feeley, K. & Gage, J.D. (2009) Macrofaunal communities and sediment structure across the Pakistan margin Oxygen Minimum Zone, North-East Arabian Sea. Deep-Sea Research II, 56(6-7), 434-448. Imajima, M. (1973) Paraonidae (Polychaeta) from Japan. Bulletin of the National Science Museum, Tokyo, 16, 254-292. Jones, M.L. (1968) Paraonis pygoenigmatica new species, a new annelid from Massachusetts (Polychaeta: Paraonidae). Proceedings of the Biological Society of Washington, 81, 323334. Katzmann, W. & Laubier, L. (1975) Paraonidae (Polychètes sédentaires) de l’Adriatique. Annalen des Naturhistorischen Museums in Wien, 79, 567-588. 233 Laubier, L. & Carton, Y. (1973) Vectoriella ramosae sp. n., un copépode parasite d’annélide polychète en Méditerranée profonde. Archives de zoologie expérimentale et générale, 114, 149-158. Laubier, L. & Ramos, J. (1974) Paraonidae (Polychètes sédentaires) de Méditerranée. Bulletin de Muséum National d’Histoire Naturelle, 3e série, 168 (Zoologie 113), 1097-1148 (dated 1973, but printed 1974). Levin, L.A., Ziebis, W., Mendoza, G.F., Growney, V.A., Tryon, M.D., Brown, K.M., Mahn, C., Gieskes, J.M. & Rathburn, A.E. (2003) Spatial heterogeneity of macrofauna at the northern California methane seeps: influence of sulfide concentration and fluid flow. Marine Ecological Progress Series, 265, 123-139. Levin, L.A., Ziebis, W., Mendoza, G.F., Growney-Cannon, V. & Walther, S. (2006) Recruitment response of methane-seep macrofauna to sulfide-rich sediments: An in situ experiment. Journal of Experimental Marine Biology and Ecology, 330(1), 132-150. Levinsen, G.M.R. 1884. Systematisk-geografisk Oversigt over de nordiske Annulata, Gephyrea, Chaetognathi og Balanoglossi. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening i Kjøbenhavn, 1883, 92-350. Mackie, A.S.Y. (1991) Paradoneis eliasoni sp. nov. (Polychaeta: Paraonidae) from Northern European waters, with a redescription of Paradoneis lyra (Southern, 1914). Ophelia, Supplement, 5, 147-155. McLelland, J.A. & Gaston, G.R. (1994) Two new species of Cirrophorus (Polychaeta: Paraonidae) from the northern Gulf of Mexico. Proceedings of the Biological Society of Washington, 107(3), 524-531. 234 Melville, R.V. (1979) Opinion 1139 Paraonis Grube, 1873 (Polychaeta, Paraonidae): Designation of a type species under the plenary powers. Bulletin of Zoological Nomenclature, 36, 114-118. Mesnil, F. (1897) Études de morphologie externe chez les Annélides. II. Remarques complémentaires sur les Spionidiens. La famille nouvelle des Disomidiens. La place des Aonides (sensu Tauber, Levinsen). Bulletin scientifique de la France et de la Belgique, 30, 83-100. Mesnil, F. & Caullery, M. (1898) Études de morphologie externe chez les Annélides. IV. La famille nouvelle des Levinséniens. Révisions des Ariciens – affinités des deux familles. Les Apistobranchiens. Bulletin scientifique de la France et de la Belgique, 31, 126-151. Petti, M.A.V., Nonato, E.F., Skowronski, R.S.P. & Navajas Corbisier, T. (2006) Bathymetric distribution of the meiofaunal polychaetes in the nearshore zone of Martel Inlet, King George Island, Antarctica. Antarctic Science, 18(2), 163-170. Read, G.B. (2000) Taxonomy and distribution of a new Cossura species (Annelida: Polychaeta: Cossuridae) from New Zealand. Proceedings of the Biological Society of Washington, 113(4), 1096-1110. Read, G. & Fauchald, K. (2013). Paraonidae. In: Read, G. & Fauchald, K. (Eds.) World Polychaeta database. Accessed through: World Register of Marine Species. Available from: http://www.marinespecies.org/aphia.php?p=taxdetails&id=903 (accessed 24 September 2013). Röder, H. (1971) Gangsysteme von Paraonis fulgens Levinsen 1883 (Polychaeta) in ökologischer, ethologischer und aktuopaläontologischer Sicht. Senckenbergiana maritima, 3, 3-51. 235 Rouse, G.W. & Fauchald, K. (1997) Cladistics and polychaetes. Zoologica Scripta, 26(2), 139204. Sardá, R., Gil, J., Taboada, S. & Gili, J.M. (2009) Polychaete species captured in sediment traps moored in northwestern Mediterranean submarine canyons. Zoological Journal of the Linnean Society, 155(1), 1-21. Southern, R. (1914) Clare Island Survey. Archiannelida and Polychaeta. Proceedings of the Royal Irish Academy, 31(47), 1-160. Storch, V. (1967) Neue Polychaeten aus der Sandfauna des Roten Meeres. Zoologischer Anzeiger, 178(1/2), 102-110. Strelzov, V.E. (1968) [Polychaetous annelids of the family Paraonidae (Polychaeta, Sedentaria) of the Barents Sea. Trudy Murmanskogo Biologicheskogo Instituta, 17, 74-95. [In Russian] Strelzov, V.E. (1973) [Polychaete worms of the family Paraonidae Cerruti, 1909 (Polychaeta, Sedentaria)]. Nauka Publishers, Leningrad, 170 pp. (In Russian; translated into English for the Smithsonian Institution and the National Science Foundation, Washington, D.C. in 1979, published by Amerind Publishing Co. Pvt. Ltd., New Delhi, 212 pp.). Surugiu, V., Dauvin, J.-C., Gillet, P. & Ruellet, T. (2008) Can seamounts provide a good habitat for polychaete annelids? Example of the northeastern Atlantic seamounts. Deep-Sea Research I, 55(11), 1515-1531. Tauber, P. (1879) Annulata danica. En kritisk revision af de i Danmark fundne Annulata Chaetognatha, Gephyrea, Balanoglossi, Discophoreae, Oligochaeta, Gymnocopa og Polychaeta. Reitzel, København, 143 pp. 236 Thiel, H., Schriever, G., Bussau, C. & Borowski, C. (1993) Manganese nodule crevice fauna. Deep Sea Research I, 40(2), 419-423. Vacchi, M., La Mesa, M. & Castelli, A. (1994) Diet of two coastal nototheniid fish from Terra Nova Bay, Ross Sea. Antarctic Science, 6(1), 61-65. Webster, H.E. (1879) The Annelida Chaetopoda of the Virginian coast. Transactions of the Albany Institute, 9, 202-272. Yeates, D. (1992) Why remove autapomorphies? Cladistics, 8(4), 387-389. 237 SUMMARY In the examination of the polychaete diversity of the Gulf of Mexico based on a comprehensive species list (Fauchald et al. 2009), I found that the shelf break is accompanied by a profound change in the polychaete fauna. Within the shallow water cluster, the polychaete fauna of 0-20 meters depth is distinct from the 20-200 m fauna. The southeastern sector of the Gulf hosts a distinct polychaete fauna, whereas the composition of the three other sectors is mostly governed by depth, rather than regional differences. The ecological classifications of polychaetes suggested by Fauchald & Jumars (1979) were revised, and each of the 829 species and five subspecies was assigned to a category in mobility, feeding appendage, and feeding strategy. The composition of the each category was examined across different depths and regions. Carnivorous polychaete species accounted for a much higher percentage of the total species numbers in the depths larger than 200 meters, whereas relative contributions of deposit feeders decreased with depth. Species were also assigned to biogeographic categories based on the current distribution records. About one third of the polychaete species have a wide distribution. This phenomenon confirms findings from other geographic regions (Knox 1957, Montiel San Martín et al. 2005). About 40% of the species are restricted to the Gulf of Mexico and the Atlantic Ocean. The portion of boreal species from the North American Atlantic coast and the tropical Caribbean and South American Atlantic coast is similar and confirms that the Gulf of Mexico polychaete fauna is transitional between both regions. The percentage of endemics is about 10%, which is comparable to other invertebrate taxa (Hedgpeth 1953, Spivey 1981). In the study of the spatial and temporal dynamics of the polychaete assemblages of the northern Gulf of Mexico, there was no decrease in abundance between 350 and 1500 meters 238 depth, as might be expected. However, between 1500 and 2100 m, polychaete abundance dropped. Seasonal changes in abundance were significant in a transect on the central continental slope. Numbers of polychaetes had nearly doubled between fall 1983 and spring 1984 and receded to the initial abundance in the fall of 1984. This spring peak in polychaete numbers may be linked to an increased availability of nutrients through riverine inflow in the spring (Aulenbach et al. 2007). In contrast to the abundance of polychaetes, the composition of their assemblages changed continuously with depth in all three transects. The seasonal changes of their abundance had no influence on the spatial or temporal turnover of polychaete diversity. All of the stations that were sampled multiple times underwent slight compositional changes. At stations that were sampled repeatedly over shorter (~1-2 years) and longer (~16-17 years) periods of time, short term changes had reversed and their polychaete faunas had approximately returned to the initial composition. The abundance and diversity of one station in the central transect had changed extensively between two sampling events that were about 16 years apart. However, the reason for this change was that, during one of the sampling events, samples were retrieved from a hydrocarbon seep. Seeps are known to host a different fauna (MacDonald et al. 1989). In the third chapter, I was able to confirm that the polychaete family Paraonidae is monophyletic. The synapomorphies, compared to the morphologically similar outgroups Cossuridae, Orbiniidae, and Questidae, are the absence of a prostomial ring due to the fusion of prostomium and peristomium, and the dorsal location of the anus. Paraonides was recovered as sister taxon of Cirrophorus and Paradoneis. 239 The prostomial antenna in species of Cirrophorus has developed twice during their evolutionary history, and is therefore considered a homoplastic character. This leaves the genus Cirrophorus polyphyletic and the genus Paradoneis paraphyletic. Both paraonid genera are considered synonyms, with Cirrophorus being the senior synonym. Two species of Paradoneis, which possess notopodial spines, rather than bifurcate chaetae, belong to a new genus. Paraonides, a genus that lacks modified notochaetae altogether, Cirrophorus, and the new genus, are sister genera. The simplistic morphology of the paraonid polychaetes left me with a low number of characters applicable for the cladistic analysis. The phylogenetic relationships between paraonid genera and species of the Cirrophorus – Paradoneis complex could only be partially resolved. Therefore, it is recommended that molecular markers are used to supplement the morphological characters in future phylogenetic studies of Paraonidae. References Aulenbach, B., Buxton, H., Battaglin, W., and Coupe, R.(2007) Streamflow and nutrient fluxes of the Mississippi-Atchafalaya River Basin and subbasins for the period of record through 2005. U.S. Geological Survey Open-File Report 2007-1080. Available from http://toxics.usgs.gov/pubs/of-2007-1080/index.html (accessed 7 June 2013). Fauchald, K., Granados-Barba, A. & Solís-Weiss, V. (2009) Polychaeta (Annelida) of the Gulf of Mexico. In: Felder, D.L. & Camp, D.K. (Eds.) Gulf of Mexico origin, waters, and biota: Volume I, Biodiversity. Texas A&M University Press, pp. 751-788. 240 Fauchald, K. & Jumars, P.A. (1979) The diet of worms: a study of polychaete feeding guilds. Oceanography and Marine Biology – An Annual Review, 17, 193-284. Hedgpeth, J.W. (1953) An introduction to the zoogeography of the northwestern Gulf of Mexico with reference to the invertebrate fauna. Publications of the Institute of Marine Science, 3(1), 107-224. Knox, G.A. (1957) The distribution of polychaetes in the Indo-Pacific. Proceedings of the 8th Pacific Science Congress, 3, 403-411. MacDonald, I.R., Boland, G.S., Baker, J.S., Brooks, J.M., Kennicutt II, M.C. & Bidigare, R.R. (1989) Gulf of Mexico hydrocarbon seep communities. Marine Biology, 101(2), 235-247. Montiel San Martín, A., Gerdes, D. & Arntz, W.E. (2005) Distributional patterns of shallowwater polychaetes in the Magellan region: a zoogeographical and ecological synopsis. Scientia Marina, 69(S2), 123-133. Spivey, H.R. (1981) Origins, distribution, and zoogeographic affinities of the Cirripedia (Crustacea) of the Gulf of Mexico. Journal of Biogeography, 8(2), 153-176. 241 APPENDIX APPENDIX. List of NGoMCS and DGoMB sampling stations of the C, E, and MT transects. Data of replicates are lumped and indicated as ranges. Study Sampling date Station Number of replicates NGoMCS November 1983 C-1 6 NGoMCS November 1983 C-2 6 NGoMCS November 1983 C-3 6 NGoMCS November 1983 C-4 6 NGoMCS November 1983 C-5 6 NGoMCS April 1984 C-1 6 NGoMCS April 1984 C-2 6 NGoMCS April 1984 C-3 5 NGoMCS April 1984 C-4 6 NGoMCS April 1984 C-5 6 NGoMCS April 1984 E-1 3 NGoMCS April 1984 E-2 3 NGoMCS April 1984 E-3 3 NGoMCS April 1984 E-4 4 NGoMCS April 1984 E-5 4 NGoMCS November 1984 C-1 5 242 Latitude Longitude Depth [m] 28.053 N 90.235 W 320 28.062 N 90.255 W 355 27.905 N 90.098 W 603 27.907 N 90.102 W 632 27.752 N 90.113 W 845 27.827 N 90.142 W 853 27.472 N 89.760 W 1325 27.492 N 89.785 W 1440 26.963 N 89.517 W 2467 26.990 N 89.543 W 2490 90.253 W 348 90.260 W 358 27.905 N 90.098 W 595 27.908 N 90.103 W 605 27.752 N 90.113 W 845 27.827 N 90.142 W 853 27.472 N 89.780 W 1320 27.473 N 90.783 W 1355 26.948 N 89.570 W 2377 26.965 N 89.621 W 2400 28.460 N 86.017 W 347 28.462 N 86.030 W 357 28.277 N 86.252 W 625 28.278 N 86.253 W 630 28.158 N 86.417 W 845 28.160 N 86.437 W 847 28.072 N 86.573 W 1330 28.073 N 86.580 W 1370 28.007 N 86.647 W 2800 28.008 N 86.648 W 2853 28.068 N 90.256 W 353 28.069 N 90.265 W 361 28.055 N APPENDIX. (continued) Study Sampling date Station Number of replicates NGoMCS November 1984 C-2 6 NGoMCS November 1984 C-3 6 NGoMCS November 1983 C-4 6 NGoMCS November 1983 C-5 6 NGoMCS November 1984 C-6 6 NGoMCS November 1984 C-7 6 NGoMCS November 1984 C-8 6 NGoMCS November 1984 C-9 6 NGoMCS November 1984 C-11 6 NGoMCS November 1984 C-12 6 NGoMCS May 1985 E-1 6 NGoMCS May 1985 E-1a 6 NGoMCS May 1985 E-1b 6 NGoMCS May 1985 E-1c 6 NGoMCS May 1985 E-2 6 NGoMCS May 1985 E-2a 6 243 Latitude Longitude Depth [m] 27.912 N 90.073 W 625 27.914 N 90.109 W 639 27.826 N 90.117 W 870 27.827 N 90.121 W 892 27.461 N 89.785 W 1433 27.469 N 89.789 W 1506 26.953 N 89.565 W 2482 26.958 N 89.570 W 2540 28.029 N 90.098 W 482 28.030 N 90.100 W 505 27.736 N 89.983 W 1007 27.744 N 90.987 W 1032 27.507 N 89.817 W 1147 27.510 N 89.823 W 1232 27.486 N 89.790 W 1389 27.496 N 89.798 W 1507 27.245 N 89.690 W 2075 28.250 N 89.693 W 2124 26.380 N 89.232 W 2915 26.387 N 89.243 W 2959 28.458 N 86.024 W 28.459 N 86.026 W 28.889 N 86.392 W 351 28.891 N 86.393 W 353 28.331 N 86.773 W 343 28.335 N 86.781 W 349 28.200 N 85.524 W 350 28.204 N 85.525 W 353 28.279 N 86.244 W 618 28.281 N 86.248 W 624 28.588 N 86.773 W 622 28.591 N 86.774 W 625 353 APPENDIX. (continued) Study Sampling date Station Number of replicates NGoMCS May 1985 E-2b 6 NGoMCS May 1985 E-2c 6 NGoMCS May 1985 E-2d 6 NGoMCS May 1985 E-2e 6 NGoMCS May 1985 E-3 6 NGoMCS May 1985 E-3a 6 NGoMCS May 1985 E-3b 6 NGoMCS May 1985 E-3c 6 NGoMCS May 1985 E-3d 6 NGoMCS May 1985 E-5 6 DGoMB May 2000 C-1 3 DGoMB May 2000 C-4 3 DGoMB May 2000 C-7 3 DGoMB May 2000 C-12 2 DGoMB May 2000 C-14 3 26.930 N DGoMB June 2000 MT-1 3 28.541 N 244 Latitude Longitude Depth [m] 28.301 N 86.301 W 625 28.313 N 86.311 W 629 28.246 N 86.158 W 616 28.248 N 86.163 W 620 28.118 N 85.872 W 627 28.131 N 85.885 W 633 28.036 N 85.666 W 618 28.048 N 85.683 W 624 28.155 N 86.411 W 28.157 N 86.418 W 28.474 N 87.000 W 850 28.488 N 87.001 W 865 28.118 N 86.319 W 858 28.119 N 86.324 W 860 28.258 N 86.611 W 847 28.263 N 86.619 W 852 28.363 N 86.799 W 847 28.367 N 86.801 W 852 28.003 N 86.640 W 2897 28.008 N 86.653 W 2904 28.059 N 28.060 N 90.249 W 819 334 336 27.452 N 89.763 W 1452 27.459 N 89.786 W 1476 27.728 N 89.977 W 1066 27.733 N 89.984 W 1080 26.379 N 26.383 N 89.241 W 2920 2922 89.564 W 2487 89.571 W 2495 89.825 W 481 89.829 W 482 APPENDIX. (continued) Study Sampling date Station Number of replicates DGoMB June 2000 MT-2 3 DGoMB June 2000 MT-3 3 DGoMB June 2000 MT-4 3 DGoMB June 2000 MT-5 3 DGoMB June 2000 MT-6 3 DGoMB June 2001 C-7 3 DGoMB June 2001 MT-1 3 DGoMB June 2001 MT-3 3 DGoMB June 2001 MT-6 3 DGoMB August 2002 MT-1 2 245 Latitude Longitude Depth [m] 28.448 N 89.672 W 676 28.451 N 89.673 W 680 28.219 N 89.492 W 983 28.220 N 89.496 W 990 27.827 N 89.165 W 27.833 N 89.166 W 27.326 N 88.662 W 2267 27.335 N 88.670 W 2290 26.997 N 87.988 W 2743 27.001 N 87.999 W 2750 27.730 N 89.981 W 1045 27.735 N 89.985 W 1072 28.535 N 89.826 W 480 28.541 N 89.831 W 490 28.223 N 89.506 W 980 28.225 N 89.513 W 984 26.986 N 89.011 W 2733 27.003 N 88.015 W 2772 28.554 N 89.821 W 28.561 N 89.823 W 1401 465 BIOGRAPHICAL STATEMENT Michael Gerhard Reuscher may have been destined to study marine worms because he was born in the town of Worms (Rheinland-Pfalz, Germany). Michael grew up in Schriesheim (Baden-Württemberg, Germany). He graduated from Heidelberg University with a Diplom (a six year degree that is equivalent to a combined BS and MS) in Biology in 2008. Michael’s thesis research was conducted at the Heidelberg University and the Senckenberg Research Institute and Natural History Museum in Frankfurt (Hessen, Germany). In the fall semester of 2008, Michael started graduate school at Texas A&M University – Corpus Christi to pursue a PhD in Marine Biology. Michael worked as teaching assistant from the fall semester of 2008 to the spring semester of 2011. From fall 2011 to fall 2013, he worked as a research assistant under Dr. Paul Montagna. At the time of completion of his dissertation, Michael had published seven peer-reviewed papers in international journals. He described one new genus and nineteen new species within four different polychaete families. For his research Michael has traveled to numerous museums and marine labs in Austria, France, Germany, Italy, Jordan, Russia, and the United States. 246

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