Cah. Biol. Mar. (2008) 49 : 123-149 New species of the genus Diarthrodes Thomson, 1882 (Copepoda: Harpacticoida: Thalestridae) from Vietnam and North-western Mexico (1) Samuel GÓMEZ1, Elena S. CHERTOPRUD2 and Francisco Neptalí MORALES-SERNA1 Unidad Académica Mazatlán, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Joel Montes Camarena s/n, Mazatlán, 82040, Sinaloa, México; fax: (52)669 982-61-33. E-mail: samuelgomez@ola.icmyl.unam.mx; neptali@ola.icmyl.unam.mx (2) Department of Hydrobiology, Biology Faculty, Moscow State University, Moscow 119899, Russia. E-mail: horsax@yandex.ru Abstract: Some specimens of the family Thalestridae (Copepoda: Harpacticoida) were gathered from sediment samples taken in the framework of two short term studies about the effects of organic enrichment on the diversity of benthic copepods from two brackish coastal systems in central (Ensenada del Pabellón lagoon) and southern (Urías system) Sinaloa during the early 1990’s and during 2005. Also some specimens of the same family were found in sediment samples taken in year 2004 during a study about the distribution and biogeography of harpacticoid copepods from Southern Vietnam. The specimens collected turned out to belong to five new species of Diarthrodes: D. imitator sp. nov., D. tripartitus sp. nov., D. hexasetosus sp. nov., D. nhatrangensis sp. nov. and D. savinkinii sp. nov. Seven species groups (I (1-2-2), II (1-2-3), III (2-1-3), IV (3-1-3), V (2-2-3), VI (3-2-2), VII (3-2-3)) are herein defined based on the number of segments of the exopod of the antenna, and on the number of segments of the exopod and endopod of the first swimming leg. Another new species attributed to group I (1-2-2), Diarthrodes apostolovii sp. nov., is created based on previous illustrations of D. assimilis from the Black Sea. Résumé : Nouvelles espèces du genre Diarthrodes Thomson, 1882 (Copepoda : Harpacticoida : Thalestridae) du Vietnam et du nord-ouest du Mexique. Quelques spécimens de la famille Thalestridae (Copepoda : Harpacticoida) ont été recueillis des échantillons de sédiment prélevés lors de deux études sur les effets de l’enrichissement en matière organique sur la diversité des copépodes benthiques de deux systèmes côtiers saumâtres dans la partie centrale (lagune Ensenada del Pabellón) et méridionale (système Urías) de Sinaloa pendant le début des années 90 et en 2005. En outre, quelques spécimens de la même famille ont été trouvés dans des échantillons de sédiment prélevés en 2004 au cours d’une étude sur la distribution et la biogéographie des copépodes harpacticoides du Vietnam méridional. Les spécimens rassemblés se sont avérés appartenir à cinq nouvelles espèces de Diarthrodes : D. imitator sp. nov., D. tripartitus sp. nov., D. hexasetosus sp. nov., D. nhatrangensis sp. nov. et D. savinkinii sp. nov. Sept groupes d’espèces (I (1-2-2), II (1-2-3), III (2-1-3), IV (3-1-3), V (2-2-3), VI (3-22), VII (3-2-3)) sont définis sur la base du nombre de segments de l’exopode de l’antenne, et sur le nombre des segments de l’exopode et de l’endopode de la première patte. Une autre nouvelle espèce attribuée au groupe I (1-2-2), Diarthrodes apostolovii sp. nov., est créée en se fondant sur les illustrations précédentes de D. assimilis de la Mer Noire. Keywords: Harpacticoida l Thalestridae l Diarthrodes l New species l Mexico l Vietnam Reçu le 27 juillet 2007 ; accepté après révision le 29 avril 2008. Received 27 July 2007; accepted in revised form 29 April 2008. 124 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Introduction Dana (1855) created the genus Westwoodia Dana, 1855 to accommodate Arpacticus nobilis Baird, 1845 (= Diarthrodes nobilis (Baird, 1845)). Some years later, Claus (1863) allocated this genus into the family Harpactidae Claus, 1863, along with eleven other genera and Boeck (1865) presented a system in which he divided the family Harpactidae into eight sections (Longipedina, Amyonea, Tachidina, Westwoodina, Harpacticina, Ameirina, Porcellidina and Setellina), the section Westwoodina being composed of two genera, Idya Philippi, 1843 (= Tisbe Lilljeborg, 1853 (Lang, 1948) and Westwoodia. Claus’ (1863) and Boeck’s (1865) systems are quite similar, but differ in that the former attributed the genera Porcellidium Claus, 1860 (= Mucrorostrum Harris & Iwasaki, 1997 (Walker-Smith, 2001)), Zaus Goodsir, 1845, Alteutha Baird, 1845, Eupelte Claus, 1860 and Oniscidium Claus, 1860 ( =Peltidium Philippi, 1839 (Lang, 1948)) to the family Peltididae, whilst Boeck (1865) included the genera Zaus and Alteutha in his section Harpacticina, and the genus Porcellidium (= Mucrorostrum) in the section Porcellidina, both within the family Harpactidae. In his monograph, Brady (1880) followed the systems proposed by Claus (1863) and Boeck (1865) to set the limits of the family, except for including, as in Brady (1880), Claus’ (1863) Peltididae amongst the Harpacticidae, the latter being composed of seven genera: Harpacticus MilneEdwards, 1840, Thalestris Claus, 1863, Dactylopus Claus, 1863 (for a complete list of synonyms see Lang (1948)), Peltidium Philippi, 1839, Westwoodia, Ilyiopsyllus Brady & Robertson 1873 (= Metis Sars, 1910) (Lang, 1948), and Zaus. Thomson (1882), following the system proposed by Brady (1880), attributed his genus Diarthrodes Thomson, 1882, with its only species, D. novae-zealandiae Thomson, 1882, found among kelp in Otago Harbour, New Zealand, to the subfamily Canthocamptineae Brady, 1878 within the family Harpacticidae. Scott (1894) described the genus Pseudowestwoodia T. Scott, 1894, and one year later T. & A. Scott (1895) suggested that Pseudowestwoodia and Pseudothalestris were identical. Sharpe (1910) noted that the name Westwoodia was preoccupied in Hymenoptera and suggested the name Parawestwoodia. In his monograph, Sars (1903-1911 & 1919-1921) divided the Harpacticoida into the Achirota and the Chirognatha, the latter being composed of the families Harpacticidae Sars, 1904, Peltidiidae Sars, 1904, Tegastidae Sars, 1904, Porcellidiidae Sars, 1904, Idyidae Sars, 1905 (= Tisbidae Stebbing, 1910 (Lang, 1948)), Thalestridae Sars, 1905, Diosaccidae Sars, 1906, Canthocamptidae Sars, 1906, Laophontidae T. Scott, 1905, Cletodidae T. Scott, 1905, Anchorabolidae Sars, 1909 (= Ancorabolidae Sars, 1909), Cylindropsyllidae Sars, 1909 (= Cylindropsyllinae Sars, 1909 of the family Canthocamptidae (Martínez-Arbizu & Moura, 1994), Tachidiidae Sars, 1909, Metidae Sars, 1910 and Balaenophilidae Sars, 1910. Sars (1903-1911 & 19191921) also united the genera Pseudothalestris Brady, 1883 and Pseudowestwoodia T. Scott, 1908 with Westwoodia (probably unaware of Sharpe’s (1910) contribution) and attributed the latter genus to the Thalestridae. Monard (1927) also unaware of Sharpe’s (1910) paper, suggested that the three genera that were united by Sars (1903-1911 & 1919-1921) to define the genus Westwoodia (Pseudothalestris, Pseudowestwoodia and Westwoodia) should bear the character of subgenera, followed Sars’s system when recognizing the position of Westwoodia within the Thalestridae which, at that time was composed of 23 genera, and also noted the close resemblance between Diarthrodes and Pseudothalestris Brady, 1883. Lang (1936) formally and definitely equated the genera Arpacticus Baird, 1845, Westwoodia, Pseudothalestris, Pseudowestwoodia and Parawestwoodia with Diarthrodes, and allocated the genus in the subfamily Dactylopusiinae Lang, 1936 (correction of Dactylopodiinae for Dactylopusiinae, ICZN 0.1356) within the Thalestridae, and latter in his monograph, he (Lang, 1948) allocated the family in the suprafamily Thalestridimorpha Lang, 1948 within the subsection Podogennonta Lang, 1948. Even though Lang’s (1936 & 1948) diagnoses are rather indeterminate and vague (Willen, 2000) his system had been followed until recently when Willen (2000) removed the subfamily Dactylopusiinae from the Thalestridae and raised it to the family level as Dactylopusiidae Lang, 1936 Willen’s (2000) course of action was based on the monophyletic status of the Dactylopusiinae as suggested by the autapomorphic shape of P1, the male P2Enp, the praecoxa of the maxillule, the loss of one seta on P4Enp3 and the shape of the praecoxal endite of the maxilla (Willen, 2000). More recently, Boxshall & Halsey (2004) decided to keep Lang’s (1936 & 1948) system regarding the acceptance and use of Lang’s (1936 & 1948) subfamily Dactylopusiinae and to reject Willen’s (2000) system and use of the Dactylopusiidae as a separate family within the Thalestridimorpha. Unfortunately, Boxshall & Halsey (2004) did not justify their decision and Willen’s (2000) system is herein adopted. A number of harpacticoid copepods of the genus Diarthodes Thomson, 1882 were found during the course of two short-term studies in a coastal system in central and southern Sinaloa State (Mexico) and in samples taken from Southern Vietnam. The Mexican specimens turned out to be representatives of three new species D. imitator sp. nov., D. tripartitus sp. nov. and D. hexasetosus sp. nov., whereas the S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA material from Vietnam turned out to be representatives of two new species D. savinkinii sp. nov. and D. nhatrangensis sp. nov. Currently, 42 species have been recognized within the genus Diarthrodes (for a complete list see below). Unfortunately the mouthparts of some species have received little attention thus making difficult further comparisons and phylogenetic analyses. Based on the descriptions and illustrations available, seven species groups (I (1-2-2), II (1-2-3), III (2-1-3), IV (3-1-3), V (2-23), VI (3-2-2), VII (3-2-3)) are proposed. These groups are based on the number of segments of the exopod of the antenna, and on the number of segments of the exopod and endopod of the first swimming leg. Such species groups might not reflect phylogeny but are useful for species separation. Also, some brief notes on the possible relationships of the species herein described are presented. Materials and methods Sediment samples for meiofauna analyses were taken during sampling campaigns in two brackish systems in central (Ensenada del Pabellón lagoon) and southern (Urías system) Sinaloa during the early 1990’s (see Gómez Noguera & Hendrickx, 1997) and during 2005 (unpublished data), respectively. Sediment samples were sieved through 500 µm and 40 µm sieves and benthic copepods were separated from the rest of the meiofauna with a stereo-microscope at 40X magnification. Specimens were stored in 70% ethanol prior to further investigation. Additional sediment samples were taken from the upper sublittoral zone of the Kai River (Nha-Trang Bay, Southern Vietnam) using hand-held plastic corers. These samples were fixed with 4% formalin and copepods were separated by flotation and sieved through 70 µm sieves. Observations and drawings at a magnification of 1000X were made from whole and dissected specimens mounted in lactophenol with a Leica compound microscope equipped with phase contrast and a drawing tube. The type material was deposited in the Copepoda collection of the Instituto de Ciencias del Mar y Limnología, Mazatlán Marine Station (Mexico). The terminology proposed by Huys & Boxshall (1991) for the general description was adopted. Abbreviations used in the text and tables are: P1-P6, first to sixth swimming legs; EXP, exopod; ENP, endopod; P1 (P2P4) EXP (ENP) 1 (2, 3) denotes the proximal (middle, distal) exopodal (endopodal) segment of P1, P2, P3 or P4; ae, aesthetasc. 125 Systematics FAMILY Dactylopusiidae Lang, 1936 Genus Diarthrodes Thomson, 1882 Diarthrodes imitator sp. nov. (Figs 1-6) Type material One female holotype (EMUCOP-010591-62) dissected and mounted onto seven slides. Collected in Ensenada del Pabellón lagoon (24º19’-24º35’N, 107º28’-107º45’W) on May 1, 1991; stn. 4 (Gómez-Noguera & Hendrickx, 1997); nitrogen content, 0.027 µmol g-1; carbon content, 1.129 µmol g-1; sediment type, clay (Gómez-Noguera & Hendrickx, 1997). Coll. S. Gómez. Type locality Ensenada del Pabellón lagoon, Sinaloa, Mexico (24º19’24º35’N, 107º28’-107º45’W). Etymology The specific name alludes to the strong resemblance to D. unisetosus Lang, 1965 and D. latisetosus Chislenko, 1978. Female Habitus (Fig. 1) fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length measured from tip of rostrum to posterior margin of caudal rami in dorsal view, 324 µm. Rostrum (not illustrated) as in D. unisetosus as illustrated by Lang (1965). Prosomites and first to fifth urosomites with plain hyaline frill; dorsal (Fig. 2A) and ventral (Fig. 2B) surface of urosomites plain except for row of spinules along caudal margin of anal segment ventrally. Genital double-somite completely fused dorsally (Fig. 2A) and ventrally (Fig. 2B), and with suture indicating former division laterally as in D. tripartitus sp. nov. (see Fig. 7B); genital field as in Fig. 2B; P6 represented by small plate bearing one slender seta. Caudal rami short, about 1.5 times as wide as long, with seven elements (Fig. 2A & B); elements I, II and III situated at the outer distal corner; seta I very long and ventral to element II, the latter transformed into strong spine; seta III slender, longer than and next to element II; setae IV and V normal in shape; seta VI somewhat longer than seta III and situated at inner distal corner; seta VII triarticulated, situated on top of insertion site of seta VI. Antennule (Fig. 3A), six-segmented, with aesthetasc on fourth and last segments; surface of first segment with two spinular rows, succeeding segments without spinules. Armature formula, 1-(1), 2-(11), 3-(8), 4-(2+ae), 5-(1), 6(11 + acrothek). Acrothek consisting of two setae fused 126 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 2. Diarthrodes imitator sp. nov. Female. A. Urosome, dorsal view, P5 bearing-somite omitted. B. Urosome, ventral view, P5 bearing-somite omitted. Scale bar: A, B, 50 µm. Figure 2. Diarthrodes imitator sp. nov. Femelle. A. Urosome, vue dorsale, le segment qui porte la P5 a été omis. B. Urosome, vue ventrale, le segment qui porte la P5 a été omis. Echelle : A, B, 50 µm. Figure 1. Diarthrodes imitator sp. nov. Female. Habitus, dorsal view. Scale bar: 100 µm. Figure 1. Diarthrodes imitator sp. nov. Femelle. Habitus, vue dorsale. Echelle : 100 µm. basally to one aesthetasc. Antenna (Fig. 4A). Allobasis with trace of division between basis and first endopodal segment, with one abexopodal seta. Exopod one-segmented, with three lateral setae, and one seta and one strong spine apically (Fig. 4B). Free endopodal segment with two lateral spines, distally with one spine, three geniculate setae and one geniculate element fused to slender seta (Fig. 4C). Mandible with strong gnathobase and unidentate pars incisiva (Fig. 4D). Coxa-basis long and armed with one long seta (Fig. 4E). Exopod and endopod one-segmented; exopod smaller than endopod, with five and six setae respectively (Fig. 4E). Maxillule (Fig. 3B). Arthrite of praecoxa with two surface setae; distally as figured. Coxa with three, basis with six setae. Endopod and exopod one-segmented, small, with three setae each. Maxilla (Fig. 4F). Syncoxa with three endites armed with one seta each. Basis produced into strong, serrate claw. Maxilliped (Fig. 4G). Basis with one proximal and one distal spinular row, with two apical setae. First endopodal segment oval, with one seta halfway of inner margin and one slender apical seta, second endopodal segment with strong claw. P1 (Fig. 5A). Intercoxal sclerite as in Fig. 5B. Coxa with median row of small spinules, with stronger spinules close to outer distal corner. Basis with inner, transverse spinular row, with spinules at base of inner and outer spines and at base of endopod. Exopod two-segmented, barely reaching S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Figure 3. Diarthrodes imitator sp. nov. Female. A. Antennule. B. Maxillule. Scale bar: A, B, 50 µm. Figure 3. Diarthrodes imitator sp. nov. Femelle. A. Antennule. B. Maxillule. Echelle : A, B, 50 µm. 127 Figure 4. Diarthrodes imitator sp. nov. Female. A. Antenna. B. Distal part of antennary exopode. C. Distal part of antennary second endopodal segment. D. Mandibular gnathobase. E. Mandibular palp. F. Maxilla. G. Maxilliped. Scale bar: A, D-G, 50 µm; B, C, 25 µm. Figure 4. Diarthrodes imitator sp. nov. Femelle. A. Antenne. B. Partie distale de l’exopode de l’antenne . C. Partie distale du deuxième segment de l’endopode de l’antenne. D. Partie distale de la mandibule. E. Palpe mandibulaire. F. Maxille. G. Maxillipède. Echelle : A, D-G, 50 µm ; B, C, 25 µm. proximal third of first endopodal segment; first segment with one outer spine, second segment with five setae/spines. Endopod three-segmented; first segment about 4.3 times as long as wide, with one seta halfway of inner margin, second segment small, as long as wide, without armature; third segment as large as preceding segment, with one small seta (arrowed in Fig. 5A; the latter is visible only in the left P1, but is absent in right P1) and two spines (outermost smaller). Figure 5. Diarthrodes imitator sp. nov. Female. A. P1 (small, slender seta arrowed). B. Intercoxal sclerite of P1. C. P2. D. Intercoxal sclerite of P2. Scale bar: A-D, 50 µm. Figure 5. Diarthrodes imitator sp. nov. Femelle. A. P1 (petit soie indiquée). B. Sclérite intercoxal de P1. C. P2. D. Sclérite intercoxal de P2. Echelle : A-D, 50 µm. 128 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM with five setae/spines. P5 (Fig. 6E). Baseoendopodal lobe weakly developed, with five elements as figured and a large apical pore (arrowed in Fig. 6E). Exopod elongate, with five setae/spines. Armature formula of swimming legs as follows: EXP ENP P1 I-0;I1I,I,1 0-1;0-0;0,II1,0 P2 P3 I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 0-1;0-2;I,2,2 0-1;0-1;I,2,3 P4 I-1;I-1;III,I1,3 0-1;0-1;I,2,2 Male Unknown. Diarthrodes tripartitus sp. nov. (Figs 7-14) Type material Figure 6. Diarthrodes imitator sp. nov. Female. A. P3. B. Intercoxal sclerite of P3. C. P4. D. Intercoxal sclerite of P4. E. P5 (apical pore arrowed). Scale bar: A-E, 50 µm. Figure 6. Diarthrodes imitator sp. nov. Femelle. A. P3. B. Sclérite intercoxal de la P3. C. P4. D. Sclérite intercoxal de la P4. E. P5 (pore apical indiqué). Echelle : A-E, 50 µm. P2 (Fig. 5C). Intercoxal sclerite as in Fig. 5D. Coxa with transverse spinular row close to outer distal corner. Basis with spinules at base of endopod; inner distal corner and middle part acutely produced. Rami three-segmented. EXP1 and EXP2 with inner seta, EXP3 with seven elements. Endopod reaching proximal third of EXP3; ENP1 with one small, inner spine; ENP2 with two inner setae (proximal seta smaller); ENP3 with five setae/spines. P3 (Fig. 6A). Intercoxal sclerite as in Fig. 6B. Coxa and basis as in P2. Exopod as in P2 except for eight setae/spines in P3EXP3. Endopod as in P2 except for width:length ratio of segments (compare Fig. 5C & Fig. 6A), and for only one inner seta in P3ENP2 and six elements in P3ENP3. P4 (Fig. 6C). Intercoxal sclerite as in Fig. 6D. EXP1 and EXP2 as in P2, unfortunately the right exopod was lost during dissection; the EXP3 as shown in Fig. 6C is considered herein as an aberration, being the normal condition with eight setae/spines. Endopod barely reaching tip of EXP2; ENP1 and ENP2 with one inner seta; ENP3 One female holotype (EMUCOP-080205-05) and one male allotype (EMUCOP-080205-06 presened in alcohol), two dissected female paratypes (EMUCOP-080205-14, EMUCOP-020805-13), three dissected male paratypes (EMUCOP-080205-10, EMUCOP-0802502-11, EMUCOP -080205-12), and two fifth copepodites, one third copepodite, one fourth copepodite and two male paratypes (EMUCOP-080205-07), one male paratype (EMUCOP080205-08), and one male and one female paratype (EMUCOP-080205-09) preserved in alcohol. Collected in the Urías system (23º11’06”N, 106º25’06”W) on February 8, 2005; stn. 4 (unpublished data); salinity 38; temperature, 22.6º C; organic carbon content, 3.52%; dissolved oxygen, 5.15 mg.l-1; biochemical oxygen demand (BOD5), 2.34 mg.l-1; sand, 77.4%; silt, 7.54%; clay, 15.1%. Coll. S. Gómez, F. N. Morales-Serna and F. E. Vargas-Arriaga. Type locality Urías system, 106º25’06”W). Sinaloa, Mexico (23º11’06”N, Etymology The specific name alludes to the three endites in the syncoxa of the maxilla, which differentiates the species from D. falcipes Marinoni, 1964 and D. dissimilis Lang, 1965. Female Habitus (Fig. 7) fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length measured from tip of rostrum to posterior margin of caudal rami in dorsal view, from 312 µm to 385 µm (mean, 343 µm; n = 4). Rostrum (Fig. 7B) fused to cephalic shield, small, general shape as in D. unisetosus as illustrated by Lang (1965). S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA 129 Figure 7. Diarthrodes tripartitus sp. nov. Female. A. Habitus, dorsal view. B. Habitus, lateral view. Scale bar: A, B, 100 µm. Figure 7. Diarthrodes tripartitus sp. nov. Femelle. A. Habitus, vue dorsale. B. Habitus, vue latérale. Echelle : A, B, 100 µm. Figure 8. Diarthrodes tripartitus sp. nov. Female. A. Urosome, dorsal view (P5 bearing-somite omitted). B. Urosome, ventral view (P5 bearing-somite omitted). C. Left caudal ramus, dorsal view. D. Left caudal ramus, ventral view. Scale bar: A, B, 100 µm; C, D, 80 µm. Figure 8. Diarthrodes tripartitus sp. nov. Femelle. A. Urosome, vue ventrale (le segment qui porte la P5 a été omis). B. Urosome, vue dorsale (le segment qui porte la P5 a été omis). C. Furca gauche, vue dorsale. D. Furca gauche, vue ventrale. Echelle : A, B, 100 µm ; C, D, 80 µm. 130 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 9. Diarthrodes tripartitus sp. nov. Female. A. Antennule. B. Mandible. C. Maxillule. D. Distal part of maxillulary arthrite. E. Distal part of maxillulary coax. F. Distal part of maxillulary basis. G. Maxillulary endopod. H. Maxillulary exopod. Scale bar: A, B, 50 µm; C, 33 µm; D-H, 25 µm. Figure 9. Diarthrodes tripartitus sp. nov. Femelle. A. Antennule. B. Mandibule. C. Maxillule. D. Partie distale de l’arthrite de la maxillule. E. Partie distale de la coxa de la maxillule. F. Partie distale de la basis de la maxillule. G. Endopode de la maxillule. H. Exopode de la maxillule. Echelle : A, B, 50 µm ; C, 33 µm ; D-H, 25 µm. Prosomites, and first to fifth urosomites with plain hyaline frill (Figs 7A-B & 8A-B); dorsal (Fig. 8A) and ventral (Fig. 8B) surface of urosomites plain except for row of spinules along caudal margin of anal segment ventrally. Genital double-somite completely fused dorsally (Fig. 8A) and ventrally (Fig. 8B), but with suture indicating former division laterally (Fig. 7B); genital field as in Fig. 8B; P6 represented by two small plates with long, slender seta (Fig. 8B). Caudal rami short, about 1.5 times as wide as long, with seven elements (Fig. 8C & D); elements I, II and III situated at outer distal corner; seta I very long and ventral to element II, the latter transformed into strong spine; seta III slender, longer than and next to element II; setae IV and V normal in shape; seta VI somewhat shorter than seta III and situated at inner distal corner; seta VII triarticulated and situated on top of insertion site of seta VI. Figure 10. Diarthrodes tripartitus sp. nov. Female. A. Antenna. B. Maxilla. C. Maxilliped. D. P5 (apical pore arrowed). Scale bar: A, 33 µm; B-D, 50 µm. Figure 10. Diarthrodes tripartitus sp. nov. Femelle. A. Antenne. B. Maxille. C. Maxillipède. D. P5 (pore apical indiqué). Echelle : A, 33 µm ; B-D, 50 µm. Antennule (Fig. 9A), seven-segmented, with aesthetasc on fourth and last segments; surface of first segment with few spinules, succeeding segments without spinular ornamentation. Armature formula, 1-(1), 2-(10), 3-(6), 4-(2+ae), 5-(1), 6-(2), 7-(6+acrothek). Acrothek consisting of two setae and one aesthetasc fused basally. Antenna (Fig. 10A). Allobasis with trace of division between basis and first endopodal segment, with one abexopodal seta. Exopod one-segmented, with four lateral and two apical setae (one of them stronger). Free endopodal segment with two lateral spines; apically with one spine, three geniculate setae and one geniculate element fused to slender seta. Mandible (Fig. 9B) with strong gnathobase and unidentate pars incisiva. Coxa-basis long and armed with one long seta. Exopod one-segmented, smaller than endopod, with four setae. Endopod one-segmented, with five elements. Maxillule (Fig. 9C). Arthrite of praecoxa with two surface setae, distally as in Fig. 9C, D. Coxa with three (Fig. 9C & E), basis with six setae (Fig. 9C & F). Endopod S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Figure 11. Diarthrodes tripartitus sp. nov. Female. A. P1. B. Intercoxal sclerite of P1. C. P2. D. Intercoxal sclerite of P2. Scale bar: A-D, 50 µm. Figure 11. Diarthrodes tripartitus sp. nov. Femelle. A. P1. B. Sclérite intercoxal de la P1. C. P2. D. Sclérite intercoxal de la P2. Echelle : A-D, 50 µm. 131 Figure 12. Diarthrodes tripartitus sp. nov. Female. A. P3. B. Intercoxal sclerite of P3. C. P4. D. Intercoxal sclerite of P4. Scale bar: A-D, 50 µm. Figure 12. Diarthrodes tripartitus sp. nov. Femelle. A. P3. B. Sclérite intercoxal de la P3. C. P4. D. Sclérite intercoxal de la P4. Echelle : A-D, 50 µm. and exopod one-segmented, small, with three setae each (Fig. 9C, G & H). Maxilla (Fig. 10B). Syncoxa with three endites; proximal and middle endites with one, distal endite with two setae. Basis produced into strong, serrate claw. Figure 13. Diarthrodes tripartitus sp. nov. Male. A. Urosome, dorsal view (P5 bearing-somite omitted). B. Urosome, ventral view (P5 bearing-somite omitted). Scale bar: A, B, 50 µm. Figure 13. Diarthrodes tripartitus sp. nov. Mâle. A. Urosome, vue dorsale (le segment qui porte la P5 a été omis). B. Urosome, vue ventrale (le segment qui porte la P5 a été omis). Echelle : A, B, 50 µm. 132 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 14. Diarthrodes tripartitus sp. nov. Male. A. Antennule. B. P1. C. P2ENP. D. P5. Scale bar: A-D, 100 µm. Figure 14. Diarthrodes tripartitus sp. nov. Mâle. A. Antennule. B. P1. C. P2ENP. D. P5. Echelle : A-D, 100 µm. Maxilliped (Fig. 10C). Basis with one proximal and one distal spinular row, with two apical setae. First endopodal segment oval, without armature, second endopodal segment with strong claw. P1 (Fig. 11A). Intercoxal sclerite as in Fig. 11B. Coxa with median row of small spinules and with stronger spinules close to outer distal corner. Basis with spinules at base of inner spine and at base of endopod, with slender setules close to inner margin on posterior face. Exopod two-segmented, barely reaching half of first endopodal segment; EXP1 with one outer spine; EXP2 with five setae/spines. Endopod two-segmented; first segment very long, about 3.5 times as long as wide, with one seta halfway of inner margin, second segment small, about twice as long as wide, with two apical spines. P2 (Fig. 11C). Intercoxal sclerite as in Fig. 11D. Coxa with spinular row close to outer distal corner. Basis with few spinules at base of endopod; inner distal corner and middle part acutely produced. Rami three-segmented. EXP1 and EXP2 with inner seta, EXP3 with seven elements. Endopod reaching proximal third of EXP3; ENP1 with one inner seta; ENP2 with two inner setae of about the same length; ENP3 with five setae/spines. P3 (Fig. 12A). Intercoxal sclerite as in Fig. 12B. Coxa and basis as in P2. Exopod as in P2 except for eight setae/spines in P3EXP3. Endopod as in P2 except for width:length ratio of segments (compare Figs 11C & 12A), and for six elements in P3ENP3. P4 (Fig. 12C). Intercoxal sclerite as in Fig. 12D. Exopod as in P2 except for eight setae/spines in P4EXP3. Endopod reaching proximal quarter of EXP3; ENP1 and ENP2 with one inner seta; ENP3 with five setae/spines. P5 (Fig. 10D). Baseoendopodal lobe well developed, reaching distal quarter of exopod, with five elements as figured and a large apical pore (arrowed in Fig. 10D), with an anterior transverse spinular row and few posterior spinules close to distal pore. Exopod elongate, with five setae/spines. S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Armature formula of swimming legs as follows: EXP ENP P1 P2 P3 P4 I-0;I1I,I,1 I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 I-1;I-1;III,I1,3 0-1;0,II,0 0-1;0-2;I,2,2 0-1;0-2;I,2,3 0-1;0-1;I,2,2 Male General shape of habitus (not shown) as in female; total body length measured from tip of rostrum to posterior margin of caudal rami in dorsal view, from 275 µm to 325 µm (mean, 290 µm; n = 7). Urosome as in female dorsally except for genital somite (Fig. 13A), ventrally with spinules close to posterior margin of third, fourth and fifth urosomites (Fig. 13B). Antennule (Fig. 14A), eight-segmented, haplocer, with aesthetasc on fifth and last segments; surface of first segment with few spinules, succeeding segments without spinular ornamentation. Armature formula difficult to define, 1-(1), 2-(10), 3-(3), 4-(4), 5-(5+ae), 6-(1), 7-(0), 8(7+acrothek). Acrothek consisting of two setae and one aesthetasc fused basally. 133 Antenna, mandible, maxillule, maxilla and maxilliped (not shown) as in female. P1 (Fig. 14B) as in female except for inner dimorphic spine of basis. P2EXP (not shown) as in female; P2ENP twosegmented, sexually dimorphic (Fig. 14C). P3 and P4 (not shown) as in female. P5 (Fig. 14D). Baseoendopodal lobe reaching distal third of exopod, with three and two anterior, transverse spinular rows, and few spinules along outer margin and at base of outer basal seta. Exopod oval, with five setae/spines. P6 (Fig. 13) represented by two asymmetrical plates. Diarthrodes hexasetosus sp. nov. (Figs 15-20) Type material One dissected female holotype (EMUCOP-080205-15) and one dissected female paratype (EMUCOP-080205-16). Figure 15. Diarthrodes hexasetosus sp. nov. Female. A. Urosome, dorsal view (P5 bearing-somite omitted). B. Urosome, ventral view (P5 bearing-somite omitted). C. Left caudal ramus, dorsal view. D. Left caudal ramus, ventral view. Scale bar: A, B, 100 µm; C, D, 50 µm. Figure 15. Diarthrodes hexasetosus sp. nov. Femelle. A. Urosome, vue dorsale (le segment qui porte la P5 a été omis). B. Urosome, vue ventrale (le segment qui porte la P5 a été omis). C. Furca gauche, vue dorsale. D. Furca gauche, vue ventrale. Echelle : A, B, 100 µm ; C, D, 50 µm. 134 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 16. Diarthrodes hexasetosus sp. nov. Female. A. Antennule. B. Antenna. Scale bar: A, 40 µm; B, 32 µm. Figure 16. Diarthrodes hexasetosus sp. nov. Femelle. A. Antennule. B. Antenne. Echelle : A, 40 µm ; B, 32 µm. Figure 17. Diarthrodes hexasetosus sp. nov. Female. A. Mandible. B. Maxillule. C. Maxillulary exopod. D. Maxillulary endopod. E. Distal part of maxillulary basis. F. Distal part of maxillulary coax. G. Distal part of maxillulary arthrite. Scale bar: A, B, 50 µm; C-G, 25 µm. Figure 17. Diarthrodes hexasetosus sp. nov. Femelle. A. Mandibule. B. Maxillule. C. Exopode de la maxillule. D. Endopode de la maxillule. E. Partie distale de la basis de la maxillule. F. Partie distale de la coxa de la maxillule. G. Partie distale de l’arthrite de la maxillule. Echelle : A, B, 50 µm; C-G, 25 µm. Collected in the Urías system (23º11’06”N, 106º25’06”W) on February 8, 2005; stn. 2 (unpublished data); salinity 39; temperature, 21.9ºC; organic carbon content, 4.11%; dissolved oxygen, 2.62 mgl-1; biochemical oxygen demand (BOD5), 0.93 mg.l-1; sand, 80.1%; silt, 6.7%; clay, 13.3%. Coll. S. Gómez, F. N. Morales-Serna and F. E. VargasArriaga. Type locality Figure 18. Diarthrodes hexasetosus sp. nov. Female. A. Maxilla. B. Maxilliped. C. P5. Scale bar: A, B, 50 µm; C, 100 µm. Figure 18. Diarthrodes hexasetosus sp. nov. Femelle. A. Maxille. B. Maxillipède. C. P5. Echelle : A, B, 50 µm ; C, 100 µm. Urías system, 106º25’06”W). Sinaloa, Mexico (23º11’06”N, Etymology The specific name alludes to the presence of six setae on the third exopodal segment of the first swimming leg. S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Figure 19. Diarthrodes hexasetosus sp. nov. Female. A. P1. B. P2. C. Intercoxal sclerite of P2. Scale bar: A, 46 µm; B, 49 µm; C, 35 µm. Figure 19. Diarthrodes hexasetosus sp. nov. Femelle. A. P1. B. P2. C. Sclérite intercoxal de la P2. Echelle : A, 46 µm ; B, 49 µm ; C, 35 µm. Female Habitus (not shown) fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length difficult to estimate due to bad condition of the only two specimens. Rostrum (not shown) seemingly as in previous species. Prosomites (not shown), and first to fifth urosomites with plain hyaline frill (Fig. 15A & B); dorsal surface of urosomites without spinular ornamentation (Fig. 15A), ventral surface with few spinules close to distal margin of third (second half of double genital-somite), fourth and fifth urosomites and along posterior margin of anal somite (Fig. 15B). Genital double-somite with trace of subdivision as figured (Fig. 15A & B); genital field as in Fig. 15B; P6 represented by two setae. Caudal rami short, about 4 times as wide as long, with seven elements (Fig. 15C & D); elements I, II and III situated at the outer distal corner; seta I very long and ventral to element II, the latter transformed into strong 135 Figure 20. Diarthrodes hexasetosus sp. nov. Female. A. P3. B. P4. C. Intercoxal sclerite of P4. Scale bar: A, B, 100 µm; C, 65 µm. Figure 20. Diarthrodes hexasetosus sp. nov. Femelle. A. P3. B. P4. C. Sclérite intercoxal de la P4. Echelle : A, B, 100 µm ; C, 65 µm. spine; seta III slender, nearly as long as and next to element II; setae IV and V normal in shape; seta VI longer than seta III and situated at inner distal corner; seta VII triarticulated and situated on top of insertion site of seta VI. Antennule (Fig. 16A) five-segmented, with aesthetasc on third and last segments, surface of first segment with few spinules, succeeding segments without spinular ornamentation. Armature formula, 1-(1), 2-(6), 3-(8+ae), 4-(1), 5-(11+acrothek). Acrothek consisting of two setae and one aesthetasc fused basally. Antenna (Fig. 16B). Allobasis without trace of division between basis and first endopodal segment, with one long abexopodal seta. Exopod two-segmented; first segment with two lateral and one apical seta, second segment with one lateral and one apical seta. Free endopodal segment with two lateral spines and two setae; apically with one seta-like element, three geniculate elements, and one geniculate seta fused to slender seta basally. 136 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Mandible (Fig. 17A) with strong gnathobase, unidentate pars incisiva and a pectinate element as figured. Coxa-basis long and armed with one long seta. Exopod and endopod one-segmented, with five setae each. Maxillule (Fig. 17B). Arthrite of praecoxa with two surface setae and armed laterally and distally as in Fig. 17G. Coxa with four (Fig. 17F), basis with six setae and ornamented with distal spinules (Fig. 17E). Endopod and exopod one-segmented, small; endopod with two, exopod with three setae (Fig. 17C & D). Maxilla (Fig. 18A). Syncoxa with three endites; proximal endite with one, middle and distal endites with two setae. Basis produced into strong, serrate claw. Maxilliped (Fig. 18B). Basis without spinules, with two distal setae. First endopodal segment oval, with one seta, second endopodal segment with strong claw. P1 (Fig. 19A). Coxa with median row of small spinules distally and with anterior strong spinules and posterior setules close to outer distal corner. Basis with spinules at base of inner and outer spines and at base of endopod. Exopod two-segmented, barely reaching proximal third of ENP1; EXP1 with one outer spine; EXP2 with six setae/spines as figured. Endopod two-segmented; first segment very long, about 4.4 times as long as wide, with one inner seta on proximal third, second segment small, about twice as long as wide, unarmed; third segment small, with two spines (innermost longer) and one posterior, small seta. P2 (Fig. 19B). Intercoxal sclerite as in Fig. 19C. Coxa without spinules. Basis with few spinules at base of endopod, at base of outer seta and on distal inner corner; inner distal corner and middle part acutely produced. Rami threesegmented. EXP1 and EXP2 with inner seta, EXP3 with seven elements. Endopod reaching half of EXP3; ENP1 with one, ENP2 with two inner setae; ENP3 with five setae/spines. P3 (Fig. 20A). Intercoxal sclerite, coxa and basis as in P2. Exopod as in P2 except for eight setae/spines in P3EXP3. Endopod as in P2 except for width: length ratio of segments (compare Fig. 20A and 19B), and for six elements in P3ENP3. P4 (Fig. 20B). Intercoxal sclerite as in Fig. 20C. Exopod as in P2 except for eight setae/spines in P4EXP3. Endopod barely reaching tip of EXP2; ENP1 and ENP2 with one inner seta; ENP3 with five setae/spines. P5 (Fig. 18C). Baseoendopodal lobe well developed, reaching tip of exopod, with five elements, with small spinules along outer margin. Exopod oval, with five setae. Armature formula of swimming legs as follows: EXP ENP P1 P2 P3 I-0;I1I,I1,1 I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 0-1;0-0;0,II1,0 0-1;0-2;I,2,2 0-1;0-2;I,2,3 P4 I-1;I-1;III,I1,3 0-1;0-1;I,2,2 Male Unknown. Diarthrodes nhatrangensis sp. nov. (Figs 21-26) Type material One dissected female holotype (EMUCOP-190404-01) and one dissected female paratype (EMUCOP-190404-02). Collected in Nha-Trang Bay, Southern Vietnam, in the upper sublittoral zone of the Kai river, between mainland and Mieu Island (12º10’60”N, 109º13’16”W) on April 19, 2004, at a depth of 10.4 m; silted crushed shell; mean particle size, 0.25 mm; silt, 25%. Coll. A. A. Udalov. Type locality Nha-Trang Bay, 109º13’16”W). Southern Vietnam (12º10’60”N, Etymology The specific name alludes to the type locality. Female Habitus (Fig. 21A) fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length from 298 µm (holotype) to 305 µm. Rostrum large, bell-shaped, distinct (Figs 21A & 22A). Prosomites, and first to fifth urosomites with plain hyaline frill; dorsal (Figs 21A & 23A) and ventral (Fig. 24A) surface of urosomites without spinular ornamentation except for spinules along posterior margin of anal somite ventrally. Genital double-somite with trace of subdivision as figured (Figs 21A, 23A & 24A); genital field as in Fig. 24A; P6 represented by two slender setae. Caudal rami short, as wide as long, with seven elements (Figs 23B & 24B); elements I, II and III situated at the outer distal corner; seta I very long and ventral to element II, the latter transformed into strong spine; seta III slender, nearly as long as and next to element II; setae IV and V normal in shape; seta VI longer than seta III and situated at inner distal corner; seta VII triarticulated and situated on top of insertion site of seta VI. Antennule (Fig. 22B), five-segmented, with aesthetasc on third and last segments, surface of first segment with few spinules, succeeding segments without spinular ornamentation. Armature formula, 1-(1), 2-(11), 3-(10+ae), 4(1), 5-(8 + acrothek). Acrothek consisting of two setae and one aesthetasc fused basally. Antenna (Fig. 22C). Allobasis without trace of division between basis and first endopodal segment, with one long abexopodal seta. Exopod three-segmented; first and second S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA 137 Figure 22. Diarthrodes nhatrangensis sp. nov. Female. A. Rostrum. B. Antennule. C. Antenna. Scale bar: A-C, 50 µm. Figure 22. Diarthrodes nhatrangensis sp. nov. Femelle. A. Rostre. B. Antennule. C. Antenne. Echelle : A-C, 50 µm. Figure 21. Diarthrodes nhatrangensis sp. nov. Female. A. Habitus, dorsal view. B. Mandible. C. Maxillule. D. Distal part of maxillulary arthrite. E. Distal part of maxillulary coax. F. Distal part of maxillulary basis. G. Distal part of maxillulary endopode. H. Distal part of maxillulary exopod. Scale bar: A, 100 µm; B, C 33 µm; D-H, 18 µm. Figure 21. Diarthrodes nhatrangensis sp. nov. Femelle. A. Habitus, vue dorsale. B. Mandibule. C. Maxillule. D. Partie distale de l’arthrite de la maxillule. E. Partie distale de la coxa de la maxillule. F. Partie distale de la basis de la maxillule. G. Partie distale de l’endopode de la maxillule. H. Partie distale de l’exopode de la maxillule. Echelle : A, 100 µm ; B, C 33 µm ; D-H, 18 µm. segments with one seta, third segment with three setae as figured. Free endopodal segment with two lateral spines and one seta; apically with one spine, three geniculate elements and one geniculate seta fused to slender element. Mandible (Fig. 21B) with strong gnathobase, bidentate pars incisiva and a strong element as figured. Coxa-basis long and armed with one long seta. Exopod and endopod one-segmented; endopod with two, exopod with six setae. Maxillule (Fig. 21C). Arthrite of praecoxa with two surface setae and armed laterally and distally as in Fig. 21D. Coxa (Fig. 21E) and basis (Fig. 21F) with five setae. Endopod and exopod one-segmented, large, with three setae each (Fig. 21G & H). Maxilla (Fig. 23C). Syncoxa with three endites; proximal and middle endites with one, distal endite with two setae. Basis produced into strong, serrate claw. Maxilliped (Fig. 23D). Basis with transverse spinular row, with one apical seta. First endopodal segment without armature, second endopodal segment with strong claw. P1 (Fig. 25A). Intercoxal sclerite as in Fig. 25C. Coxa without spinules. Basis with spinules close to inner proximal corner and at base of endopod. Exopod twosegmented, reaching proximal half of first endopodal segment; EXP1 with one outer spine; EXP2 with five setae/spines. Endopod two-segmented; first segment elongate, about 2.5 times as long as wide (measured at its widest part), with one seta halfway of inner margin, second segment small, about twice as long as wide, with two spines (outermost smaller). P2 (Fig. 25B). Intercoxal sclerite as in Fig. 25D. Coxa without spinules. Basis without spinules; inner distal corner and middle part acutely produced. Rami three-segmented. EXP1 and EXP2 with inner seta, EXP3 with seven elements. Endopod reaching half of EXP3; ENP1 with one, ENP2 with two inner setae (distalmost smaller); ENP3 with five setae/spines. P3 (Fig. 26A). Intercoxal sclerite as in Fig. 26C. Coxa and basis as in P2. Exopod as in P2 except for eight setae/spines in P3EXP3. Endopod as in P2 except for six elements in P3ENP3. 138 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 23. Diarthrodes nhatrangensis sp. nov. Female. A. Urosome, dorsal view (P5 bearing-somite omitted). B. Right caudal ramus, dorsal. C. Maxilla. D. Maxilliped. Scale bar: A, C, D, 50 µm; B, 33 µm. Figure 23. Diarthrodes nhatrangensis sp. nov. Femelle. A. Urosome, vue dorsale (le segment qui porte la P5 a été omis). B. Furca droite, vue dorsale. C. Maxille. D. Maxillipède. Echelle : A, C, D, 50 µm ; B, 33 µm. P4 (Fig. 26B). Intercoxal sclerite as in Fig. 26D. Exopod as in P2 except for eight setae/spines in P4EXP3. Endopod reaching proximal third of EXP3; ENP1 and ENP2 with one inner seta; ENP3 with five setae/spines. P5 (Fig. 24C). Baseoendopodal lobe well developed, reaching tip of exopod, with five elements. Exopod oval, with five setae. Figure 25. Diarthrodes nhatrangensis sp. nov. Female. A. P1. B. P2. C. Intercoxal sclerite of P1. D. Intercoxal sclerite of P2. Scale bar: A-D, 50 µm. Figure 25. Diarthrodes nhatrangensis sp. nov. Femelle. A. P1. B. P2. C. Sclérite intercoxal de la P1. D. Sclérite intercoxal de la P2. Echelle : A-D, 50 µm. Figure 24. Diarthrodes nhatrangensis sp. nov. Female. A. Urosome, ventral view (P5 bearing-somite omitted). B. Right caudal ramus, ventral view. C. P5. Scale bar: A, C, 50 µm; B, 33 µm. Figure 24. Diarthrodes nhatrangensis sp. nov. Femelle. A. Urosome, vue ventrale (le segment qui porte la P5 a été omis). B. Furca droite, vue ventrale. C. P5. Echelle : A, C, 50 µm ; B, 33 µm. S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Figure 26. Diarthrodes nhatrangensis sp. nov. Female. A. P3. B. P4. C. Intercoxal sclerite of P3. D. Intercoxal sclerite of P4. Scale bar: A-D, 50 µm. Figure 26. Diarthrodes nhatrangensis sp. nov. Femelle. A. P3. B. P4. C. Sclérite intercoxal de la P3. D. Sclérite intercoxal de la P4. Echelle : A-D, 50 µm. Armature formula of swimming legs as follows: EXP ENP P1 I-0;III,I,1 0-1;0,II,0 P2 P3 P4 I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 I-1;I-1;III,I1,3 0-1;0-2;I,2,2 0-1;0-2;I,2,3 0-1;0-1;I,2,2 139 Figure 27. Diarthrodes savinkinii sp. nov. Female. A. Urosome, dorsal view (P5 bearing-somite omitted). B. Left caudal ramus, dorsal view. C. Urosome, ventral view (P5 bearing-somite omitted). D. Left caudal ramus, ventral view. Scale bar: A, C, 100 µm; B, D, 50 µm. Figure 27. Diarthrodes savinkinii sp. nov. Femelle. A. Urosome, vue dorsale (le segment qui porte la P5 a été omis). B. Furca gauche, vue dorsale. C. Urosome, vue ventrale (le segment qui porte la P5 a été omis). D. Furca gauche, vue ventrale. Echelle : A, C, 100 µm ; B, D, 50 µm. Type locality Nha-Trang Bay, 109º13’16”W). Southern Vietnam (12º10’60”N, Etymology Male Unknown. Diarthrodes savinkinii sp. nov. (Figs 27-31) Type material One dissected female holotype (EMUCOP-190404-03), one fourth copepodite and three fifth copepodite paratypes preserved in alcohol (EMUCOP-190404-04). Collected in Nha-Trang Bay, Southern Vietnam, in the upper sublittoral zone of the Kai river, between mainland and Mieu Island (12º10’60”N, 109º13’16”W) on April 19, 2004, at a depth of 10.4 m; silted crushed shell; mean particle size, 0.25 mm; silt, 25%. Coll. A. A. Udalov. The species is named in honour to Dr Oleg Vladimirovits Savinkin (Severstov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia). Female Habitus (not shown) fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length 409 µm. Rostrum (not shown) large, bell-shaped, distinct. Prosomites, and first to fifth urosomites with plain hyaline frill; dorsal (Fig. 27A) and ventral (Fig. 27C) surface of urosomites without spinular ornamentation except for spinules along posterior margin of anal somite ventrally. Genital double-somite with trace of subdivision as figured 140 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Figure 28. Diarthrodes savinkinii sp. nov. Female. A. Antennule. B. Maxilla. C. Maxilliped. Scale bar: A-C, 50 µm. Figure 28. Diarthrodes savinkinii sp. nov. Femelle. A. Antennule. B. Maxille. C. Maxillipède. Echelle : A-C, 50 µm. (Fig. 27A & C); genital field as in Fig. 27C; P6 represented by two setae. Caudal rami slightly longer than wide, with seven elements (Fig. 27B & D); elements I, II and III situated at the outer distal corner; seta I very long and ventral to element II, the latter transformed into strong spine; seta III slender, longer than and next to element II; setae IV and V normal in shape; seta VI as long as seta III and situated at inner distal corner; seta VII triarticulated. Antennule (Fig. 28A), five-segmented, with aesthetasc on third and last segments, surface of segments without spinules. Armature formula, 1-(1), 2-(11), 3-(10+ae), 4-(1), 5-(8+acrothek). Acrothek consisting of two setae and one aesthetasc fused basally. Antenna (Fig. 29A). Allobasis without trace of division between basis and first endopodal segment, with one long abexopodal seta. Exopod three-segmented; first and second segments with one seta, third segment with three setae as figured. Free endopodal segment with two lateral spines and one seta; apically with one spine, three geniculate elements and one geniculate seta fused to slender element. Mandible (Fig. 29B) with strong gnathobase, bidentate pars incisiva and a strong element as figured. Coxa-basis long and armed with one long seta. Exopod and endopod one-segmented; endopod with two, exopod with six setae. Maxillule (Fig. 29C). Arthrite of praecoxa with two Figure 29. Diarthrodes savinkinii sp. nov. Female. A. Antenna. B. Mandible. C. Maxillule. Scale bar: A, B, 50 µm; C, 33 µm. Figure 29. Diarthrodes savinkinii sp. nov. Femelle. A. Antenne. B. Mandibule. C. Maxillule. Echelle : A, B, 50 µm ; C, 33 µm. surface setae, laterally with three and distally with five. Coxa and basis with five setae. Endopod and exopod onesegmented, large, with three setae each. Maxilla (Fig. 28B). Syncoxa with three endites; proximal and middle endites with one, distal endite with two setae. Basis produced into strong, serrate claw. Maxilliped (Fig. 28C). Basis without spinules, with one apical seta. First endopodal segment without armature, second endopodal segment with strong claw. P1 (Fig. 30A). Intercoxal sclerite as in D. nhatrangensis sp. nov. Basis with spinules at base of endopod. Exopod two-segmented, reaching proximal half of first endopodal segment; EXP1 with one outer spine; EXP2 with six setae/spines. Endopod two-segmented; first segment elongate, about 2 times as long as wide (measured at its widest part), with one seta halfway of inner margin, second segment small, about twice as long as wide, with two spines (outermost smaller). P2 (Fig. 30B). Intercoxal sclerite as in D. nhatrangensis sp. nov. Basis with spinules at base of endopod; inner distal corner weakly produced, middle part acutely produced. Rami three-segmented. EXP1 and EXP2 with inner seta, EXP3 with seven elements. Endopod reaching half of S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA Figure 30. Diarthrodes savinkinii sp. nov. Female. A. P1. B. P2. Scale bar: A, B, 50 µm. Figure 30. Diarthrodes savinkinii sp. nov. Femelle. A. P1. B. P2. Echelle : A, B, 50 µm. EXP3; ENP1 with one, ENP2 with two inner setae (distalmost smaller); ENP3 with five setae/spines. P3 (Fig. 31A). Intercoxal sclerite and coxa as in D. nhatrangensis sp. nov. Basis as in P2. Exopod as in P2 except for eight setae/spines in P3EXP3. Endopod as in P2 except for six elements in P3ENP3. P4 (not shown) badly damaged during dissection. Probably as in D. nhatrangensis sp. nov. P5 (Fig. 31B). Baseoendopodal lobe well developed, reaching far beyond exopod, with five elements. Exopod oval, with five setae. Armature formula of swimming legs as follows: EXP ENP P1 P2 P3 P4 I-0;III,I1,1 I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 I-1;I-1;III,I1,3 0-1;I,I,0 0-1;0-2;I,2,2 0-1;0-2;I,2,3 0-1;0-1;I,2,2 Male Unknown. Discussion The genus Diarthrodes Thomson, 1882 was created to allocate D. novae-zealandiae Thomson, 1882 from Otago 141 Figure 31. Diarthrodes savinkinii sp. nov. Female. A. P3. B. P5. Scale bar: A, 71 µm; B, 50 µm. Figure 31. Diarthrodes savinkinii sp. nov. Femelle. A. P3. B. P5. Echelle : A, 71 µm ; B, 50 µm. Harbour (New Zealand). At present there are 42 valid species within Diarthrodes. These are: D. nobilis (Baird, 1845), D. minutus (Claus, 1863), D. ponticus (Kričagin, 1873), D. novae-zealandiae, D. imbricatus (Brady, 1883), D. andrewi (T. Scott, 1894), D. major (Scott & Scott, 1895), D. pygmaeus (Scott & Scott, 1895), D. assimilis (Sars, 1906), D. sarsi (A. Scott, 1909), D. pusillus (Brady, 1910), D. tumidus (Brady, 1910), D. intermedius (T. Scott, 1912), D. nanus (T. Scott, 1914), D. purpureus (Gurney, 1927), D. aegideus (Brian, 1927), D. roscoffensis (Monard, 1935), D. gurneyi Lang, 1948, D. campbelliensis Lang, 1948, D. feldmanni Bocquet, 1953, D. cystoecus Fahrenbach, 1954, D. falcipes, D. unisetosus, D. dissimilis, D. glaber Wells, 1967, D. hirami Por, 1967, D. fahrenbachi Bodin, 1968, D. drachi Bodiou, 1974, D. gravellicola Soyer, 1975, D. ponticus orientalis Apostolov, 1975, D. tetrastachyus Yeatman, 1976, D. lilacinus Pallares, 1977, D. parvulus Pallares, 1977, D. latisetosus Chislenko, 1978, D. zavodniki Apostolov & Petkovski, 1980, D. brevipes Wells & Rao, 1987, D. imitator sp. nov., D. tripartitus sp. nov., D. hexasetosus sp. nov., D. nhatrangensis sp. nov., D. savinkinii sp. nov. and D. apostolovii sp. nov. Unfortunately the mouthparts of some species have received little attention and some other species have been reported with different armature complements in mouth 142 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM appendages or swimming legs, thus making difficult and even senseless further comparisons and phylogenetic analyses. Evidently, an in depth revision of the genus is urgently needed to shed some light on the phylogenetic relationships of the species currently attributed to the genus Diarthodes. The species within Diarthodes can be grouped into seven groups based on the combination of the number of segments of the antennal exopod, the number of segments of P1 endopod, and the number of segments of P1 exopod (Table 1). Such species groupings might not reflect phylogeny and should be taken cautiously, but it is useful for species separation. These groups are: segmented, P1ENP two-segmented). Diarthrodes zavodniki, D. savinkinii sp. nov. and D. nhatrangensis sp. nov. are the species within this group (Table 1f). Diarthrodes zavodniki is unique within this group by the presence of two outer spines only on P2P4EXP3. Two outer spines have been reported also in the P3EXP3 and P4EXP3 of D. hirami and D. gurneyi (see Gurney, 1927, Lang, 1948), and in the P2EXP3 of D. minutus (see Sars, 1906). VII (3-2-3) (A2EXP three-segmented, P1EXP twosegmented, P1ENP three-segmented). I (1-2-2) (A2EXP one-segmented, P1EXP twosegmented, P1ENP two-segmented). Diarthrodes assimilis? sensu Apostolov (1972: 217-218, figs 84-93) T. Scott (1912) described D. intermedius (= Pseudothalestris intermedia T. Scott, 1912 (Lang, 1936)) from South Orkney Islands (Scotia Bay). T. Scott’s (1912) description lacks detail and only the female antennule and the maxilliped, female P1, female and male P2, and female and male P5 are shown in his illustrations and nothing is said about the A2EXP. It has to be noted that Pallares (1977) probably unaware of Lang’s (1948) decision to consider D. nanus and D. intermedius as distinct species, kept Lang’s (1936) view regarding the synonymy of these two species. The condition of the A2EXP of D. intermedius remains unknown and there is little to attribute this species to group I (1-2-2) but it is suggested to provisionally allocate this species to this species group. Brady (1910) described D. tumidus (= Pseudothalestris tumida Brady, 1910 (Lang, 1936)) from Observatory Bay (Kerguelen). The condition of the A2EXP regarding the number of segments (see also Lang, 1948: 537), and the number of setae on the P1EXP2, P1ENP1 and ENP2 remains unclear and it is suggested to attribute provisionally D. tumidus to this species group. Apostolov (1972) reported D. assimilis from the Black Sea but omitted any comment on the morphology of the species. Apostolov’s (1972) figures clearly show that his material does not belong to D. assimilis but to a new species, Diarthrodes apostolovii sp. nov. (see below for description) herein placed in group I(1-2-2). II (1-2-3) (A2EXP one-segmented, segmented, P1ENP three-segmented). III (2-1-3) (A2EXP two-segmented, segmented, P1ENP three-segmented). IV (3-1-3) (A2EXP three-segmented, segmented, P1ENP three-segmented). V (2-2-3) (A2EXP two-segmented, segmented, P1ENP three-segmented). VI (3-2-2) (A2EXP three-segmented, P1EXP twoP1EXP oneP1EXP oneP1EXP twoP1EXP two- Diarthrodes apostolovii sp. nov. Material examined. None. Diagnosis based on Apostolov’s (1972) original figures. Type locality Black Sea. Etymology This species is named after Dr. A. Apostolov for his contribution to the knowledge of harpacticoid copepods from the Black Sea. Male Habitus fusiform, tapering from posterior margin of cephalothorax to anal somite; maximum width at posterior margin of cephalothorax; total body length from 700 µm to 750 µm. Prosomites and urosomites without spinular ornamentation, except for ventral spinules on posterior margin of anal somite. Caudal rami short, about 1.5 times as wide as long. Antennule, eight-segmented, haplocer. Antenna with allobasis armed with one abexopodal seta. Exopod one-segmented, with four lateral and two apical setae. Free endopodal segment with two lateral spines; apically with one spine, three geniculate setae and one geniculate element fused to slender seta. Mandible, maxillule and maxilla unknown. Basis of maxilliped with one apical seta. First endopodal segment oval, without armature, second endopodal segment with strong claw. P1 with two-segmented rami. Exopod two-segmented, barely reaching half of first endopodal segment; EXP1 with one outer spine; EXP2 with six setae/spines. ENP1 elongate, about 7.3 times as long as wide, with one inner seta on S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA proximal quarter; ENP2 with two pectinate spines (outermost shorter) seta halfway of inner margin. P2EXP three-segmented; EXP1 and EXP2 with inner seta; EXP3 with seven setae/spines. Endopod twosegmented, sexually dimorphic; ENP1 with inner seta; ENP2 with six elements (five elements plus outer apophysis?). P3EXP three-segmented; EXP1 and EXP2 with inner seta; EXP3 with eight setae/spines. Endopod threesegmented; ENP1 with one, ENP2 with two inner setae; ENP3 with six setae/spines. P4EXP unknown. Endopod three-segmented; ENP1 and ENP2 with one inner seta; ENP3 with five setae/spines. Baseoendopodal lobe of P5 with one inner and two apical elements. Exopod with 5 elements. P6 represented by two plates with three setae each. Armature formula of swimming legs as follows: EXP ENP P1 P2 P3 P4 I-0;I1I,I1,1* I-1;I-1;III,I1,2 I-1;I-1;III,I1,3 I-1;I-1;III,I1,3** 0-1;0,II,0 Dimorphic 0-1;0-2;I,2,3 0-1;0-1;I,2,2 *The shape of the elements (except for proximal outer spine) of P1EXP2 is difficult to define from Apostolov’s (1972) figure. However, based on other species this seems to be the most probable armature formula. **The P4EXP remains unknown, but based on other species, this seems to be the most probable armature formula. Female Unknown. Remarks Apostolov (1972) reported D. assimilis from the Black Sea but omitted any comment on the morphology of the species and presented only illustrations of the male habitus, antennule, antenna, maxilliped, P1, P2, P3, P4ENP, P5 and P6. Apostolov’s (1972) figures clearly show that his material does not belong to D. assimilis but to a new species, Diarthrodes apostolovii sp. nov. This new species has been allocated herein in group I(1-2-2) by the combination of a two-segmented A2EXP, P1ENP and P1EXP. Diarthrodes apostolovii sp. nov. seems to be more closely related to D. glaber and D. hirami by the presence of six (one inner, two apical and three outer) elements on the two-segmented P1EXP2. Diarthrodes apostolovii sp. nov. and D. glaber can be separated from D. hirami by the armature formula of P3EXP3 (with three outer elements in Diarthrodes apostolovii sp. nov. and D. glaber, but with two outer spines only in D. hirami) and P3ENP3 (with three inner setae in Diarthrodes apostolovii sp. nov. and D. glaber, but with two inner setae only in D. hirami). Diarthrodes glaber can be separated from D. hirami by the number of segments of the female antennule (six-segmented in D. glaber, fivesegmented in D. hirami) and by the armature formula of P4EXP3 (with three outer spines in D. glaber, but with two 143 outer spines in D. hirami). Unfortunately, the antennule and the armature formulae of P2ENP and P4EXP of D. apostolovii sp. nov. remain unknown and nothing can be said on this regard. Diarthrodes imitator sp. nov. has been placed in group II(1-2-3) based on the one-segmented exopod of the antenna, the two-segmented P1EXP and the three-segmented P1ENP. Diarthrodes imitator sp. nov., D. unisetosus from Dillon Beach (California), D. latisetosus from the Sea of Japan, and D. aegideus from Italy are unique within this species group in that they possess two inner setae in the P2ENP2. On the other hand, D. imitator sp. nov. seems to be more closely related to D. unisetosus and to D. latisetosus than to D. aegideus. Diathrodes imitator sp. nov. and D. unisetosus share the armature formula of all swimming legs (except for P1ENP3 -with two elements in D. unisetosus, but with three elements in D. imitator sp. nov.), the P1-P4 EXP:ENP length ratio, the number of segments of female antennule, and the number of setae on the maxillary endites and endopod of maxilliped. Also, it has to be noted that these two species and D. gurneyi from Port Taufiq (Egypt) are unique within this group in that they possess one inner seta in P3ENP2. However, D. gurneyi is unique within this group in the P3-P4EXP3 (with two outer spines only). Diarthrodes imitator sp. nov. and D. unisetosus differ in the relative length of the setae of the baseoendopod and exopod of female P5 (compare Lang’s (1965: 189) figure 103-f and Fig. 6E in the present study), number of setae of female P6 (with two setae in D. unisetosus, but with one seta in D. imitator sp. nov.), antenna ( with allobasis in D. unisetosus, but with basis in D. imitator sp. nov.), and antennary exopod (with seven setae in D. unisetosus, but with five elements in D. imitator sp. nov.). Differences were observed also in the number of setae on the coxa, basis and endopod of the maxillule and in the number of setae of the exopod and endopod of the mandible. Diarthrodes imitator sp. nov. and D. latisetosus share the presence of an antennary basis and the armature formulae of all swimming legs except for P3ENP2 (with two inner setae in D. latisetosus, but with one inner seta in D. imitator sp. nov. – the latter condition is similar for D. unisetosus and D. gurneyi). From Chislenko’s (1978) illustrations of D. latisetosus, these two species can be separated also by the ventral spinular ornamentation of urosomites (with spinules in D. latisetosus, but without spinules in D. imitator sp. nov.), number of segments of the female antennule (seven-segmented in D. latisetosus, but six-segmented in D. imitator sp. nov.), number of setae on the antennary exopod (with seven setae in D. latisetosus, but with five setae in D. imitator sp. nov.), relative length of P3ENP (reaching tip of P3EXP2 in D. latisetosus, but reaching middle of P3EXP3 in D. imitator sp. nov.) and P4ENP (reaching proximal third of P4EXP2 in D. latisetosus, but reaching tip of P4EXP2 in D. imitator 144 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM sp. nov.), relative length of female P5EXP and baseoendopodal and exopodal setae (compare Chislenko’s (1978: 166) figure 4-7, and Fig. 6E in the present study). Differences were found also in the number of setae of the female antennule, of the endopod of the mandible, of the coxa, basis, exopod and endopod of the maxillule, and of the first endopodal segment of the maxilliped. However, these setae are often difficult to see and there is little point in trying to analyze these differences. The male of D. imitator sp. nov. remains unknown and nothing can be said about the differences in the dimorphic features between these species. Diarthrodes tripartitus sp. nov. has been placed in group I (1-2-2) by the combination of the one-segmented exopod of the antenna, and the two-segmented P1EXP and P1ENP. Diarthrodes tripartitus sp. nov., D. falcipes from southeastern Brazil and D. dissimilis from Dillon Beach (California) share the seven-segmented female antennule and the armature formula of P1-P4 (except for P1ENP2 with two elements in D. dissimilis and D. tripartitus sp. nov., but with three elements in D. falcipes) and the sexual male dimorphism (number of segments of the male antennule, shape of the inner spine of basis of P1, and armature formula and relative length of the setae of the male P5) and are unique within this species-group by the presence of two inner setae in the female P2ENP2 (as in D. imitator sp. nov., D. unisetosus, D. latisetosus and D. aegideus). From their descriptions, D. dissimilis, D. falcipes and D. tripartitus sp. nov. cannot be separated neither by the armature formula of P1-P4 (except, as noted above, for P1ENP2) nor by the EXP:ENP length ratio of the male and female P1-P4, nor by the male P5. Diarthrodes dissimilis (see Lang, 1965), D. falcipes (see Marinoni, 1964) and D. tripartitus sp. nov. can be separated by the female P5 BENP:EXP length ratio. The female P5 baseoendopodal lobe reaches the middle and the distal third of the exopod in D. dissimilis and D. tripartitus sp. nov., respectively. The baseoendopodal lobe reaches the tip of the exopod in D. falcipes. Marinoni (1964) omitted the description/illustration of the mandible and the maxillule. From Marinoni’s (1964) and Lang´s (1965) descriptions of the maxilliped and maxilla of D. falcipes and D. dissimilis respectively, the maxilliped of D. tripartitus sp. nov. is more similar to that observed for the latter in the lack of the single accessory seta of the claw. The maxilla of D. dissimilis possesses two endites with two setae each. The maxilla of D. falcipes was described as possessing two endites, the proximal and distal endites with one and two setae, respectively. Diarthrodes tripartitus sp. nov. was shown to possess three endites on the maxillary syncoxa. The proximal and middle endites bear one seta each, and the distal endite bears two slender elements. Diarthrodes hexasetosus sp. nov. has been attributed to species-group V(2-2-3) based on the presence of a two- segmented exopod of the antenna, two segmented P1EXP and three-segmented P1ENP. The armature formulae of P2P4 remain unknown for D. pusillus and D. sarsi. The P1EXP of the latter is also unknown. Also the condition of the antenna (with basis or allobasis) remains doubtful for all the species within this group. The rest of the species share the same armature formula of P1-P4, and D. hexasetosus sp. nov. seems to be unique in that this species possesses six setae/spines in the P1EXP2. The species-group herein referred to as group V(3-2-2) is defined by the presence of a three-segmented exopod of the antenna, and a two-segmented P1EXP and P1ENP. To this group belong D. zavodniki from Rovinj (Yugoslavia), and D. savinkinii sp. nov. and D. nhatrangensis sp. nov. from southern Vietnam. The female of D. zavodniki remains unknown and so the condition of the female antennule and P2ENP. On the other hand, the males of D. savinkinii sp. nov. and D. nhatrangensis sp. nov. remain unknown thus being impossible further comparisons between these two species and D. zavodniki. Within this group D. zavodniki seems to be unique in that this species presents two outer spines in P2-P4EXP3 (the other two species possess three outer spines). Diarthrodes savinkinii sp. nov. and D. nhatrangensis sp. nov. share the armature formula of P1ENP and P2-P3 (the armature formula of P4 of D. savinkinii sp. nov. remains unknown), and the armature formulae and general shape of mouthparts. These two species can be separated by the armature formula of P1EXP (with six setae/spines in Diarthrodes savinkinii sp. nov., but five elements in D. nhatrangensis sp. nov.), and by the relative length of the setae of the P5 (compare Fig. 24C and 31B). Acknowledgements We are grateful to Sergio Rendón Rodríguez (Instituto de Ciencias del Mar y Limnología, U.N.A.M.) and to Febe E. Vargas Arriaga for their help during field work in Urías system and for their help during sample processing. We are also grateful to the Russian-Vietnamese Technical and Scientific Tropical Center, to Dr Oleg V. Savinkin and Dr Temir A. Britaev (Severstov Institute of Ecology and Evolution) and Dr Alex A. Udalov (Shirshov Institute of Oceanology) for their support during field work in southern Vietnam. This is a contribution to project IN217606-2 financed by the Research and Technological Innovation Projects Support Programme (Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica) of the Office for General Affairs of the Academic Staff (Dirección General de Asuntos del Personal Académico) of the National Autonomous University of Mexico (U. N.A. M.), and to project No. 06-04-48106 financed by the Russian Foundation for Basic Research. S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA References Apostolov A. 1972. Catalogue des copépodes harpacticoides marins de la Mer Noire. Zoologischer Anzeiger, 188: 202-254. Apostolov A. 1973. Apport vers l’étude d´harpacticoides pontiques habitant les algues marines. Zoologischer Anzeiger, 191: 263-281. Apostolov A. 1975. Les harpacticoides marins de la Mer Noire. Description de quelques formes nouvelles. Vie et Milieu, 25: 165-178. Apostolov A. & Marinov T. 1988. Copepoda, Harpacticoida, Fauna Bulgarica 18. In: Aedibus Academiae Scientiarum Bulgaricae, Sofia: 1-384. Apostolov A.G. & Petkovski T.P. 1980. Copépodes harpacticoides de la mer Adriatique (Région de Rovigne). Acta Zoologica Bulgarica, 15: 24-35. Bocquet C. 1953. Sur un copépode harpacticoïde mineur, Diarthrodes feldmanni, n. sp. Bulletin de la Société Zoologique de France, 78: 101-105. Bodin P. 1968. Copépodes harpacticoides des étages bathyal et abyssal du Golfe de Gascogne. Mémoires du Muséum National d’Histoire Naturelle, 55: 1-107. Bodiou J.-Y. 1974. Copépodes harpacticoides des sables fins infralittoraux de Banyuls-Sur-Mer. Description d’une forme nouvelle de Diarthrodes (Thomson). Vie et Milieu, 24: 119-126. Boeck A. 1865. Oversigt over de ved Norges Kyster I agttagne Copepoder henhoerende til Calanifdernes, Cyclopidernes og Harpactidernes Familier. Forhandlinger I Videnskabsselskabet I Kristiania 1864: 226-282. Boxshall G. A. & Halsey S. H. 2004. An introduction to copepod diversity. Vol. 1. The Ray Society: London. 421 pp. Brady G. S. 1880. A monograph of the free and semi-parasitic Copepoda of the British Islands 2. The Ray Society. 182 pp. Brady G.S. 1883. Report on the Copepoda collected by H. M. S. Challenger during the years 1873-76. Report on the Scientific Results of the Voyage of HMS Challenger, Zoology, 8: 1-142. Brady G.S. 1910. Die marinen Copepoden der Deutschen Südpolar Expedition 1901-1903. I. Über die Copepoden der Stämme Harpacticoida, Cyclopoida, Notodelphyoida und Caligoida. Dt. Südpolar Expedition, 11(Zool. 3): 497-594. Brian A. 1921. I Copepodi Harpacticoidi del Golfo di Genova. Genova: 1-112. Brian A. 1927. Descrizione di specie nuove o poco conosciute di copepodi bentonici del mare Egeo. (Nota preliminare). Bollettino dei Musei di Zoologia e Anatomia comparata della R. Universita di Genova, (2)7(18): 1-37. Chislenko L. L. 1967. Copepoda Harpacticoida of the Karelian coast of the White Sea. Proceedings of the White Sea Biological Station, Zoological Institute, 7: 48-196. Chislenko L. L. 1978. New species of harpacticoid copepods (Copepoda, Harpacticoida) from the Possjet Bay of the Sea of Japan. Trudy Zoologicheskogo Instituta, Akademi Nauk SSSR, 61: 161-192. Claus C. 1863. Die frei lebenden Copepoden mit besonderer berücksichtigung der Fauna Deutschlands, der Nordsee und des Mittelmeeres. Verlag von Wilheml Engelmann. 230 pp. Dana J.D. 1855. Crustacea. In: United States exploring expedition during the years 1838-1842 under the command of 145 Charles Wilkes, 13(2): 686-1618 (1853), atlas pls. 1-88 (1855). Fahrenbach W.-H. 1954. A new species of the genus Diarthrodes (Crustacea, Copepoda) parasitic in a red alga. Journal of the Washington Academy of Sciences, 44: 326-329. Fahrenbach W.-H. 1962. The biology of a harpacticoid copepod. La Cellule, 62: 303-376. Farran G.P. 1913. Marine Entomostraca. In: A biological survey of Clare Island in the county of Mayo, Ireland, and of the adjoining district. Proceedings of the Royal Irish Academy, (B)31(45): 1-20. Gómez Noguera S.E. & Hendrickx M. 1997. Distribution and abundance of meiofauna in a subtropical coastal lagoon in the South-eastern Gulf of California, Mexico. Marine Pollution Bulletin, 34: 582-587. Gurney R. 1927. Report on the Crustacea:-Copepoda (Littoral and semi-parasitic). Cambridge Expedition to the Suez Canal, 1924. Transactions of the Zoological Society of London, 22, Part 4, No. 6: 451-577. Huys R. & Boxshall G.A. 1991. Copepod evolution. The Ray Society: London. 468 pp. Lang K. 1934. Marine Harpacticiden von der Campbell-Insel und einigen anderen Südlichen Inseln. Kungl. Fysiografiska Sällskapets Handlingar, N. F. Bd 45 Nr. 14. Lang K. 1936. Copepoda Harpacticoida. Further zoological results of the Swedish Antarctic expedition 1901-1903, 3: 6-68. Lang K. 1948. Monographie der Harpacticiden I & 2. A.-B. Nordiska Bokhandeln: Stockholm. 1682 pp. Lang K., 1965. Copepoda Harpacticoidea from the Californian Pacific coast. Kungliga Svenska Vetenskapsakademiens Handlingar, 10: 1-560. Marinoni R.C. 1964. Diarthrodes falcipes n. sp. (HarpacticoideaCopepoda) encontrada em algas do litoral Catarinense. Boletim da universidade do Parana, Conselho de Pesquisas, Zoologia, 2: 60-73. Martinez Arbizu P. & Moura G. 1994. The phylogenetic position of the Cylindropsyllinae Sars (Copepoda, Harpacticoida) and the systematic status of the Leptopontiinae Lang. Zoologische Beiträge N.F., 35: 55-77. Michailova-Neikova M. & Voinova-Stavreva F. 1971. Contribution to the study on the Harpacticoida (Crust., Copepoda) of the Bulgarian Black Sea coast. Annuaire de l’Université de Sofia, Faculté de Biologie, 63: 37-43. Monard A. 1927. Synopsis universalis generum Harpacticoidarum. Zoologische Jahrbücher, 54:139-176. Monard A. 1928. Les Harpacticoïdes marins de Banyuls. Archives de Zoologie Expérimentale et Générale, 67: 259-443. Monard A. 1935. Étude sur la faune des harpacticoïdes marins de Roscoff. Travaux de la Station Biologique de Roscoff, 13: 5-87. Pallares R.E. 1968. Copépodos marinos de la Ría Deseado (Santa Cruz, Argentina) Contribución sistemático-ecológica II. Physis, 27: 245-262. Pallares R.E. 1977. Copépodos harpacticoides marinos de Tierra del Fuego (Argentina). Isla de los Estados II. El género Diarthrodes Thomson, 1882. Contribuciones Científicas CIBIMA, 14: 1-15. Por F. 1960. Littorale Harpacticoiden der Nordwest-Küsten des Schwarzen Meeres. Travaux du Museum d’Histoire Naturelle “Gr. Antipa”, 2: 97-143. 146 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM Por F.D. 1967. Level bottom harpacticoida (Crustacea, Copepoda) from Elat (Red Sea), part I. Israel Journal of Zoology, 16: 101-165. Sars G.O. 1903-1911. An account of the Crustacea of Norway. Copepoda Harpacticoida. Parts I-XXXVI. Bergen Museum 5:1-443. Sars G.O. 1906. Copepoda Harpacticoida. Parts XI-XII. Thalestridae (continued), Diosaccidae (part). An account of the Crustacea of Norway, with short descriptions and figures of all the species, 5: 133-156. Sars G.O. 1919-1921. An account of the Crustacea of Norway. Copepoda, supplement. Parts I-X. Bergen Museum, 7: 1-121. Scott A. 1909. The Copepoda of the Siboga Expedition. Part I. Free living, littoral and semi- parasitic Copepoda. SibogaExpeditie, 29a: 1-323. Scott T. 1894. Additions to the fauna of the Firth of Forth. Part III. 12 Report of the Fishery Board for Scottland, 3: 300-310 Scott T. 1894. Report on Entomostraca from the Gulf of Guinea. The Transactions of the Linnean Society of London, 2nd Ser Zoology, 6: 1-161. Scott T. 1912. The Entomostraca of the Scottish National Antarctic Expedition, 1902-1904. Transactions of the Royal Society of Edinburgh, 68: 521-599. Scott T. 1914. Remarks on some Copepoda from the Falkland Islands collected by Mr. Rubert Vallentin, F. L. S. Annals and Magazine of Natural History, 8: 369-379. Scott T. & Scott A. 1895. On some new and rare Crustacea from Scottland. Annals and Magazine of Natural History, 6: 50-59. Sharpe R.W. 1910. Notes on the marine Copepoda and Cladocera of Woods Hole and adjacent regions, including a synopsis of the genera of the Harpacticoida. Proceedings of the United States National Museum, 38: 405-436. Soyer J. 1974. Contribution a l’étude des copépodes harpacticoides de Méditerranée Occidentale. 10. Quelques Thalestridae Sars, Lang, recuellis sur substrat meuble. Description de Diarthrodes gravellicola n. sp. Vie et Milieu, 24: 277-284. Thomson G.M. 1882. On the new Zealand Copepoda. Transactions and Proceedings of the New Zealand Institute, 15: 93-116. Vervoort W. 1964. Free-living Copepoda from Ifaluk Atoll in the Caroline Islands. United States National Museum Bulletin, 236: 1-431. Walker-Smith G.K. 2001. Porcellidium poorei, a new species of Porcellididae (Copepoda : Harpacticoida) from seagrass in Port Phillip Bay, Victoria, Australia, and a review of the family. Journal of Crustacean Biology, 21: 653-664. Wells J.B.J. 1967. The littoral Copepoda (Crustacea) of Inhaca Island, Mozambique. The Royal Society of Edinburgh, 67: 189358. Wells J.B.J. & Rao G.C. 1987. Littoral Harpacticoida (Crustacea: Copepoda) from Andaman and Nicobar Islands. Memoirs of the Zoological Survey of India, 16: 1-385. Willen E. 2000. Phylogeny of the Thalestridimorpha Lang, 1944 (Crustacea, Copepoda). Cuvillier Verlag: Göttingen. 233 pp. Yeatman H.C. 1976. Marine littoral copepods from Jamaica. Crustaceana, 30: 201-219. S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA 147 Table 1. Armature formulae of the species groups of the genus Diarthrodes. Tableau 1. I (1-2-2) (A2EXP one-segmented, P1EXP two-segmented, P1ENP two-segmented). I(1-2-2) A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP 1D. andrewi dissimilis 3D. falcipes 4D. glaber 5D. gravellicola 6D. hirami 7D. intermedius 8D. tumidus 9D. apostolovii sp. nov. 10D. tripartitus sp. nov. 2D. 7 7 7 6 6 5 7 8 7 1/5? Allobasis 1/7 Allobasis 1/6 Allobasis 1/5 Allobasis 1/4 Allobasis 1/5 Allobasis 1or2?/4 Allobasis 1/6 Basis 1/6 0,121 0,113 0,113 0,123 0,113 0,123 0,111 0,121 0,123 0,113 1,020 1,020 1,030 1,020 1,020 1,020 1,020 1,—1,020 1,020 P2 P3 P4 EXP ENP EXP ENP EXP ENP -,-,—1,1,223 1,1,223 1,1,223 1,1,223 1,1,223 -,-,—-,-,—1,1,223 1,1,223 -,-,—1,2,221 1,2,221 1,1,221 1,1,221 1,1,221 -,-,—-,-,—-,-,—1,2,221 -,-,—1,1,323 1,1,323 1,1,323 1,1,323 1,1,322 -,-,—-,-,—1,1,323 1,1,323 -,-,—1,2,321 1,2,321 1,2,321 1,2,321 1,2,221 -,-,—-,-,—1,2,321 1,2,321 -,-,—1,1,323 1,1,323 1,1,323 1,1,323 1,1,322 -,-,—-,-,—-,-,—1,1,323 -,-,223 1,1,221 1,1,221 1,1,221 1,1,221 1,1,221 -,-,—-,-,—1,1,221 1,1,221 1After T. Scott (1894), Lang (1948). 2After Lang (1965). 3After Marinoni (1964). 4After Wells (1967). 5After Soyer (1974). 6After Por (1967). 7After T. Scott (1912), Lang (1948). 8After Brady (1910), Lang (1948). Brady (1910) showed four setae on the P1EXP2, two outer elements in P1ENP1 and four elements in P1ENP2. 9After Apostolov (1972) (see group VII (3-2-3) and description of the species below). 10Present study. II (1-2-3) (A2EXP one-segmented, P1EXP two-segmented, P1ENP three-segmented). II(1-2-3) 11D. A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP nanus aegideus 13D. gurneyi 14D. unisetosus 15D. drachi 16D. parvulus 17D. latisetosus 18D. novae-zealandiae 19D. imitator sp. nov. 12D. 7 7 7 6 7 7 7 9? 6 Basisa 1/7;1/6b 1/7 1/6 Allobasis 1/6 Allobasis 1/7 1/7 Basis 1/7 1/3 Basis 1/5 0,113 0,113 0,113 0,113 0, 113 0,113 0,113 -,—0,113 1,0,020 1,0,020 1,0,020 1,0,020 1,0,020 1,0,020 1,0,030 1,0-0?a 1,0,030 P2 P3 P4 EXP ENP EXP ENP EXP ENP 1,1,223 1,1,223 1,1,223 1,1,223 1,1,223 1,1,123 1,1,223 -,-,—1,1,223 1,1,221 1,2,221 1,1,221 1,2,221 1,1,221 1,1,221 1,2,221 -,-,—1,2,221 1,1,323 1,1,323 1,1,322 1,1,323 1,1,323 1,1,123 1,1,323 -,-,—1,1,323 1,2,321 1,2,221 1,1,321 1,1,321 1,2,321 1,2,221 1,2,321 -,-,—1,1,321 1,1,323 1,1,323 1,1,322 1,1,323 1,1,323 1,1,123 1,1,323 -,-,—1,1,323 1,1,221 1,1,221 1,1,221 1,1,221 1,1,221 1,1,221 1,1,221 -,-,—1,1,221 11After T. Scott (1914), Lang (1948), Pallares (1977). Pallares (1977) unaware of Lang’s (1948) decision to consider D. nanus and D. intermedius as distinct species, kept Lang’s (1936) view regarding the synonymy of these two species. Also, it has to be noted that Pallares (1977, Lam. I, Fig. 13) erroneously omitted the outer spine of P1EXP1 of D. parvulus; aPallares (1977, Lám. I, Fig. 4) showed the A2 with basis; bLang (1948) diagnosed the species as having a one-segmented A2EXP with six setae. 12After Brian (1927), Lang (1934, 1948). 13After Gurney (1927), Lang (1948). 14After Lang (1965). 15After Bodiou (1974). 16After Pallares (1977). Pallares (1977, Lam. I, Fig. 13) erroneously omitted the outer spine of P1EXP1. 17After Chislenko (1978). 18After Thomson (1882), Lang (1948). aThe condition of the P1ENP of D. novae-zealandiae remains doubtful and has been provisionally attributed to this species group. 19Present study. III (2-1-3) (A2EXP two-segmented, P1EXP one-segmented, P1ENP three-segmented). III(2-1-3) 20D. purpureus A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP 5 - 2/3,2 1,2,4 1,0,020 P2 EXP P3 ENP EXP P4 ENP EXP ENP 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 20After Gurney (1927), Lang (1948) .../... 148 NEW SPECIES OF DIARTHRODES FROM MEXICO AND VIETNAM IV (3-1-3) (A2EXP three-segmented, P1EXP one-segmented, P1ENP three-segmented). IV(3-1-3) 21D. A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP - fahrenbachi Basis 3/1,1,4 020 1,0-1,030 P2 EXP -,-,—- 123c 22D. 5 nobilis Allobasis 3/2,1,4d 2/1,3h 124e P3 P4 ENP EXP ENP EXP -,-,—- -,-,—- -,-,—- -,-,—- 1,1,222 1,0,020 ENP -,-,—1,1,221b 1,1,223 1,2,221a 1,1,323 1,2,321 1,1,323 1,2,221g 224f 21After Bodin (1968). 22After Sars (1906), Gurney (1927), Lang (1948), Apostolov (1973), Vervoort (1964), Pallares (1968, 1977), Claus (1863), Chislenko (1967), Apostolov & Marinov (1988). Apostolov (1972) reported D. nobilis from the Black Sea but omitted any comment on the morphology of the species. Pallares (1977) reported D. nobilis from Isla de Los Estados but omitted the description of her material. aSars (1906), Vervoort (1964) and Apostolov & Marinov (1988) reported the presence of two inner setae on P2ENP2 and one outer spine on P2ENP3; bSars (1906) and Vervoort (1964) reported one inner seta on P4ENP2; cVervoort (1964), Apostolov (1973) and Apostolov & Marinov (1988) reported one inner, two apical and three outer elements in one-segmented P1EXP. It has to be noted that Vervoort (1964: 144) reversed the P1EXP and P1ENP in his written description; dSars (1906), Vervoort (1964), Pallares (1968) and Apostolov & Marinov (1988) showed a three-segmented A2EXP with two, one and four setae on the proximal, medial and distal segments, respectively; ePallares (1968: 248, Lám. II, Fig 1) reported the presence of eight setae in the written description and seven setae in her illustration of P1EXP, and Sars (1906) and Michailova-Neikova & Voinova-Stavreva (1971) described the P1EXP as having seven elements; fChislenko (1967) showed the P1EXP with eight elements; gApostolov & Marinov (1988) reported the presence of two inner setae on P4ENP2; hThe A2EXP shown by Claus (1863, Taf. XXI, Fig. 3) seems to be two-segmented, with one and three setae on the first and second segments, respectively, and Lang (1948: 530) re-diagnosed the species with a three-segmented A2EXP with seven setae in all. V (2-2-3) (A2EXP two-segmented, P1EXP two-segmented, P1ENP three-segmented). V(2-2-3) 23D. A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP campbellensis imbricatusa 25D. pusillus 26D. pygmaeus 27D. sarsi 28D. hexasetosus sp. nov. 24D. 6 8 7 6 5 Allobasis 2/2,5 2/4? 2/-,2/3,4 2/1,3 2/3,2 0,113 0,112 0,013 0,113 0,—0,123 1,0,030 1,0,020 1,030 1,0,0-0 1,0,030 1,0,030 P2 P3 P4 EXP ENP EXP ENP EXP ENP 1,1,223 1,1,223 -,-,—1,1,223 -,-,—1,1,223 1,2,221 1,2,221 -,-,—1,2,221 -,-,—1,2,221 1,1,323 1,1,323 -,-,—1,1,323 -,-,—1,1,323 1,2,321 1,2,321 -,-,—1,2,321 -,-,—1,2,321 1,1,323 1,1,323 -,-,—1,1,323 -,-,—1,1,323 1,1,221 1,1,221 -,-,—1,1,221 -,-,—1,1,221 23After Lang (1934), Lang (1948). 24After Brady (1883), T. Scott (1912), Lang (1948). aFemale unknown. 25After Brady (1910), Lang (1948). 26After T. Scott & A. Scott (1895), Lang (1948), Apostolov & Marinov (1988). Apostolov (1972) reported D. pygmaeus from the Black Sea but omitted any comment on the morphology of the species. 27After A. Scott (1909), Lang (1948). 28Present study. VI (3-2-2) (A2EXP three-segmented, P1EXP two-segmented, P1ENP two-segmented). VI(3-2-2) A1 A2 A2EXP P1 No. segm. Basis/Allo No. segm/setae EXP ENP zavodniki savinkinii sp. nov. 5 31D. nhatrangensis sp. nov. 5 29D. 30D. Allobasis 3/1,1,4 Allobasis 3/1,1,3 Allobasis 3/1,1,3 0,121 0,123 0,113 1,020 1,110 1,110 P2 EXP P3 ENP EXP P4 ENP EXP ENP 1,1,222 -,-,—-a 1,1,322 1,2,321 1,1,322 1,2,221 1,1,223 1,2,221 1,1,323 1,2,321 -,-,—- -,-,—1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 29after Apostolov & Petkovski (1980). aThe female remains unknown. 30Present study. 31Present study. VII (3-2-3) (A2EXP three-segmented, P1EXP two-segmented, P1ENP three-segmented). VII(3-2-3) A1 A2 A2EXP P1 P2 No. segm. Basis/Allo No. segm/setae EXP ENP EXP ENP 32D. 33D. assimilis brevipes 5 6 3/2,1,4 Allobasis 3/2,1,3 0,113 0,123 1,0,020 1,0,030 P3 EXP P4 ENP EXP ENP 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,2,221 S. GÓMEZ, E.S. CHERTOPRUD, F.N. MORALES-SERNA 34D. cystoecus 6e 35D. 36D. feldmanni lilacinus 37D. 38D. 39D. 0,123g 1,0,030c 1,0,020g 0,123 1,0,030 0,113 1,0,030 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 6 8 -a 3/2,1,2b d Allobasis 3/1,1,2f Allobasis 3/2,1,2 Basisa 3/2,1,4 minutus 6 3/2,1,4e 1,1,222d -,-,—- ponticus 6b -a 6 8 7 8 0,113b 1,0,020b 0,112a 1,0,030c 0,123 1,0,020 0,023c 0,123 1,0,020 0,023 1,0,020 0,023 1,0,020 0,113 1,0,020 ponticus orientalis roscoffensis 41D. tetrastachyus 42D. major 40D. 149 Allobasis Basisd Allobasis Allobasis 3/2,1,3 3/2,1,2e 3/2,0,3 3/2,1,4 3/1,1,4 3/2,1,3 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,2,221 -,-,—- -,-,—- -,-,—- -,-,—- 1,1,223 1,2,221 1,1,323 1,2,321 1,1,323 1,1,221 1,1,223 1,1,223 1,1,223 1,1,223 1,2,221 1,1,221 1,2,221 1,1,221 1,1,323 1,1,323 1,1,323 1,1,323 1,2,321 1,2,2(3)21 1,2,321 1,2,321 1,1,323 1,1,323 1,1,323 1,1,323 1,1,221 1,1,221 1,2,221 1,2,221 32After Sars (1906), T. Scott (1912), Lang (1948), Apostolov & Marinov (1988). Apostolov (1972) reported D. assimilis from the Black Sea but omitted any comment on the morphology of the species. Apostolov’s (1972) figures clearly show that his material does not belong to D. assimilis but to a new species, Diarthrodes apostolovii sp. nov. (see below for description) herein placed in group I(1-2-2). 33After Wells & Rao (1987). 34After Pallares (1977), Fahrenbach (1954, 1962), Wells & Rao (1987). Pallares (1977) supports Fahrenbach’s (1962) opinion that D. cystoecus and D. feldmanni are in fact synonyms, but refrained from synonymising these species because she could not make comparisons with fresh material of D. feldmanni. Pallares (1977) suggested that Fahrenbach (1954) based his description of D. cystoecus on a male and not on a female as Fahrenbach (1954) assumed. Pallares (1977) might be right based on the P5 presented by Fahrenbach (1954), but it is also evident that the specimen was a copepodite (probably CIV or CV) based on the lack of sexual dimorphism in A1 and P2ENP. On the other hand, from Fahrenbach’s table (1962: 311-312, Table I) about the development of D. cystoecus it is not possible to be certain if he (Fahrenbach, 1954) described a fourth or fifth male copepodite. Wells & Rao (1987) found specimens of D. cystoecus in samples taken from the Middle and South Andamans and observed four varieties of females that, to a greater or lesser degree, differ from Pallares’ (1977) description (Wells & Rao, 1987). However, based on the evident similarity to D. cystoecus and given the insufficient evidence to place their material in separate species, Wells & Rao (1987) preferred to attribute their material to D. cystoecus rather than to create at least two new species and/or subspecies. aPallares (1977) did not mention whether the A2 present basis or allobasis; b Pallares (1977) showed a three-segmented A2EXP with two, one and two setae on proximal, medial and distal segment, respectively (the same armature for A2EXP was observed by Wells & Rao (1987)); c Pallares (1977) reported two spines and a small setae apically on P1ENP3; dFahrenbach (1954, 1962) presented A2 with allobasis; eFharenbach (1954) showed a six-segmented A1; f Fharenbach (1954) three-segmented A2EXP bearing one, one and two setae in the proximal, medial and distal segment respectively; g Fharenbach (1954) described an armature of 0,123 and 1,0,020 for P1EXP and ENP (the same armature formula was given by Wells & Rao (1987)). 35After Bocquet (1953). Bocquet (1953) did not give the armature for P2-P4EXP1, EXP2 and ENP1. These have been inferred from other species. 36After Pallares (1977). aPallares (1977: 6) described de A2 with allobasis, but in her Lám. II, Fig. 4, she showed the A2 with basis. 37After Claus (1863), Apostolov & Marinov (1988). Apostolov (1972) reported D. minutus from the Black Sea but omitted any comment on the morphology of the species. aApostolov & Marinov (1988) showed the P1EXP2 with four setae/spines and did not mention the armature formulae for the other legs; bthe armature formula and number of segments of P1 is not clear enough in Claus (1863) and Sars (1906) showed the P1EXP2 with five elements; cSars (1906) illustrated the P1ENP3 with two claws and one small seta; dSars (1906) illustrated the male P2EXP3 with two outer spines; eSars (1906) illustrated the A2EXP as three-segmented, with two, one and four setae on the proximal, medial and distal segments respectively. 38After Brian (1921, 1927), Farran (1913), Monard (1928), Lang (1948), Apostolov (1973), Por (1960) (as D. dubius (Brian)), Apostolov & Marinov (1988) (both as D. ponticus and as D. dubius). Apostolov (1972) reported D. ponticus and D. dubius from the Black Sea but omitted any comment on the morphology of the species. aApostolov (1973) remained silent regarding the number of segments of A1; bLang (1948) diagnosed the species as having a five- or six-segmented A1, and Farran (1913), Por (1960) and Apostolov & Marinov (1988) reported a six-segmented A1; cBrian (1921, 1927), Farran (1913), Monard (1928), Lang (1948), Por (1960) and Apostolov & Marinov (1988) reported the P1EXP2 without inner seta; dPor (1960) reported the A2 with basis; ePor (1960) reported the presence of a three-segmented A2EXP with two, one and two setae on the proximal, medial and distal segments, respectively. 39After Apostolov (1975), Apostolov & Marinov (1988). 40After Monard (1935), Lang (1948). 41After Yeatman (1976). 42After T. Scott & A. Scott (1895), Lang (1948), Chislenko (1967).