Abstract
Small molluscs are known to be particularly abundant towards the poles. Although recent studies on sub-Antarctic waters of the southernmost tip of South America have begun to show a highly diversified small-sized fauna, micromolluscs have not yet received sufficient attention. Recently, samplings targeting the smallest molluscan benthic fauna have been conducted in the sub-Antarctic waters of South America, providing material of three new minute species occurring in The End of the World (Tierra del Fuego, Isla de los Estados and Burdwood Bank). The present study describes Pachykellya fuegiensis n.sp. (Neoleptonidae), Benthocardiella ituartei n.sp. and Benthocardiella finisterra n.sp. (Condylocardiidae). These are not only the smallest bivalves currently known from the area, but are also smaller than any other species thus far known from the adjacent Antarctic waters, and are included among the smallest species of their respective genera. To confirm generic placement, the type species of Pachykellya (P. edwardsi F.B. Bernard 1897) and Benthocardiella (B. pusilla Powell 1930) are studied for the first time with scanning electron microscopy. This study allows to amend the previous descriptions of hinge teeth number, morphology and arrangement for these genera. Based on these new findings, Pachykellya and Benthocardiella are here reported for the first time in South America.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Batistão AR, Passos FD (2020) New data on Warrana besnardi, a tiny bivalve mollusk from the Southwestern Brazilian coast. Am Malacol Bull 38:55–59. https://doi.org/10.4003/006.038.0104
Berke SK, Jablonski D, Krug AZ, Roy K, Tomasovych A (2013) Beyond Bergmann’s rule: size–latitude relationships in marine Bivalvia world-wide. Glob Ecol Biogeogr 22:173–183. https://doi.org/10.1111/j.1466-8238.2012.00775.x
Bernard FB (1896) Études comparatives sur la coquille des lamellibranches. Condylocardia, type nouveau de lamellibranches. J Conchyliol 44:169–207
Bernard F (1897) Sur quelques coquilles de lamellibranches de l’Île Stewart. Bull Mus Natl Hist Nat 3:309–314
Combosch DJ, Collins TM, Glover EA, Graf DL, Harper EM, Healy JM, Kawauchi GY, Lemer S (2017) Family-level tree of life for bivalves based on a Sanger-sequencing approach. Mol Phylogenet Evol 107:191–208. https://doi.org/10.1016/j.ympev.2016.11.003
González VL, Giribet G (2015) A multilocus phylogeny of archiheterodont bivalves (Mollusca, Bivalvia, Archiheterodonta). Zool Scr 44:41–58. https://doi.org/10.1111/zsc.12086
Ituarte C, Zelaya DG (2015) A redescription of Malvinasia Cooper & Preston, 1910 (Bivalvia: Galeommatoidea), with the description of a new species. J Molluscan Stud 81:455–465. https://doi.org/10.1093/mollus/eyv027
Linse K (2002) The shelled Magellanic Mollusca: with special reference to biogeography relations in the Southern Ocean. Theses Zool 34:1–252
Middelfart P (2002a) A revision of the Australian Condylocardiinae (Bivalvia: Carditoidea: Condylocardiidae). Molluscan Res 22:23–85. https://doi.org/10.1071/MR02001
Middelfart P (2002b) Revision of the Australian Cuninae sensu lato (Bivalvia: Carditoidea: Condylocardiidae). Zootaxa 112:1–121. https://doi.org/10.11646/zootaxa.112.1.1
Moran AL, Woods HA (2012) Why might they be giants? Towards an understanding of polar gigantism. J Exp Biol 215:1995–2002. https://doi.org/10.1242/jeb.067066
Nicol D (1964) An essay on size of marine pelecypods. J Paleontol 38:968–974
Nicol D (1966) Size of pelecypods in Recent marine faunas. Nautilus 79:109–113
Nicol D (1970) Antarctic pelecypod faunal peculiarities. Science 168:1248–1249
Passos FD, Batistão AR, Bieler R (2021) When size matters: the first comprehensive anatomical study of a species of “Condylocardiidae”, an extremely miniaturized bivalve. Peer J 9:e12108. https://doi.org/10.7717/peerj.12108
Powell AWB (1927) Deep-water Mollusca from south-west Otago, with descriptions of 2 new genera and 22 new species. Rec Canterb Mus 3:113–124
Powell AWB (1930a) New species of New Zealand Mollusca from shallow-water dredgings. Part 1. Trans Proc N Z Inst 60:532–543
Powell AWB (1930b) New species of New Zealand Mollusca from shallow-water dredgings. Part 2. Trans Proc N Z Inst 61:536–546
Powell AWB (1931) Descriptions of some new species of recent Mollusca, mainly from the sub-Antarctic islands of New Zealand. Rec Canterb Mus 3:371–376
Powell AWB (1933) Marine Mollusca from the Bounty Islands. Rec Canterb Mus 4:29–39
Rivadeneira MM, Villafaña JA, Gordillo S, Bayer S, Nielsen SN (2015) Hobbits from the deep south: historical drivers of dwarfism in modern Antarctic bivalves. Congr Geol Chil 14:635–638
Roy K, Jablonski D, Martien KK (2000) Invariant size–frequency distributions along a latitudinal gradient in marine bivalves. Proc Natl Acad Sci USA 97:13150–13155. https://doi.org/10.1073/pnas.97.24.13150
Salas C, Gofas S (1998) Description of four new species of Neolepton Monterosato, 1875 (Mollusca: Bivalvia: Neoleptonidae), with comments on the genus and on its affinity with the Veneracea. Ophelia 48:35–70. https://doi.org/10.1080/00785236.1998.10428676
Thiele J (1912) Die antarktischen Schnecken und Muscheln. Deutsche Südpolar-Expedition 1901–1903. Wiss Ergeb 13 Zool 5:185–285
Valentine JW, Jablonski D, Kidwell S, Roy K (2006) Assessing the fidelity of the fossil record by using marine bivalves. Proc Natl Acad Sci USA 103:6599–6604. https://doi.org/10.1073/pnas.0601264103
WoRMS Editorial Board (2021) World register of marine species. http://www.marinespecies.org at VLIZ. Accessed Jun 19, 2021.
Zelaya DG (2005) The bivalves from the Scotia Arc Island: Species richness and faunistic affinities. Sci Mar 69:113–122. https://doi.org/10.3989/scimar.2005.69s2113
Zelaya DG (2015) Marine bivalves from the Argentine coast and continental shelf: secies diversity and assessment of the historical knowledge. Am Malacol Bull 33:245–262. https://doi.org/10.4003/006.033.0204
Zelaya DG, Ituarte C (2004) The genus Neolepton Monterosato, 1875 in Southern South America (Bivalvia: Neoleptonidae). J Molluscan Stud 70:123–137. https://doi.org/10.1093/mollus/70.2.123
Zelaya DG, Güller M, Ituarte C (2020) Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia). Zool J Linn Soc 190:558–591. https://doi.org/10.1093/zoolinnean/zlz144
Acknowledgements
The authors greatly acknowledge Bruce Marshall and Peter Middelfart for sharing comments on New Zealand and Australian representatives of the genera considered herein, and B. Marshall for helping us to obtain some specific literature; Gene Coan for alerting us on the presence of specimens of Benthocardiella in LACM; and John Slapcinsky and Gustav Paulay for the facilities provided during the visit to the FlMNH. Bruce Marshall and an anonymous reviewer provided valuable comments for improving the Ms. Photographs of P. edwardsi are copyrighted by the Museum of New Zealand Te Papa Tongarewa (CC BY 4.0).
Funding
This study was funded by UBACYT 20020150100195BA and PICT 2016–2983. This work is contribution N° 57 MPA Namuncurá (Law 26.875). The authors are members of the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Author information
Authors and Affiliations
Contributions
MG and DZ both designed and contributed equally to this publication, including sampling, sorting, systematic studies and manuscript writing.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no conflict of interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Güller, M., Zelaya, D.G. The smallest marine bivalves from the end of the world (Tierra del Fuego, Isla de Los Estados and Burdwood Bank). Polar Biol 45, 777–787 (2022). https://doi.org/10.1007/s00300-022-03018-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00300-022-03018-3