Meeting Abstract

P1.25  Thursday, Jan. 3  Molecular phylogenetic analysis of nudibranchs from McMurdo Sound, Antarctica SHIELDS, C.C.*; MARKO, P.B.; WOODS, H.A.; MORAN, A.L.; Clemson Univ.; Clemson Univ.; Univ. of Montana at Missoula; Clemson Univ. shields@clemson.edu

Although the shallow water benthic community in the Southern Ocean (SO) is diverse and unique, comprehensive studies of the phylogenetic origins and diversity of Antarctic taxa are still in their infancy. We have therefore begun to use molecular sequences to investigate the phylogenetic and biogeographic origins of shallow water (5-30 m) members of the nudibranch community in McMurdo Sound, Antarctica. Mitochondrial cytochrome-c oxidase I (COI) sequences from Antarctic specimens and combined with all available sequences from GenBank reveal at least 14 clades or lineages of Antarctic nudibranchs (with representatives of at least 5 nominal species) that are all at least 12% divergent from their closest relative in the dataset. Approximately two thirds of these lineages are sister-groups to different non-polar clades, suggesting numerous colonizations of the SO. The remaining Antarctic lineages form separate monophyletic clades, each apparently diversifying within the SO. Additionally, we sequenced DNA from egg masses from temperate species of known parentage and have verified that masses can be readily identified to species using COI. This provides an important tool for understanding the reproductive ecology and life-history evolution of animals in the SO, which, due to slow growth and extreme temperature sensitivity, are difficult to study under laboratory conditions.