Systematics and distribution of shelled molluscs (Gastropoda, Bivalvia and Scaphopoda) from the South Shetland Islands to the Bellingshausen Sea, West Antarctica

The knowledge of the systematics and distribution of molluscs from the area of West Antarctica, mainly of the Bellingshausen Sea, remains relatively poor. Only 3 families and 11 species of molluscs were recorded in the Bellingshausen Sea, while 2 families and 3 species were recorded from Peter I Island. This apparently low number of species is the result of poor sampling in this area. An integral study of the benthic ecosystem was carried out in this area by the Spanish Antarctic Program: BENTART research cruises during the austral summer season in 2003 and 2006 on the continental shelf and lower slope from 53 to 3304 metres. A total of 3133 individuals belonging to 118 species of shelled molluscs were identified, of which 571 individuals corresponding to 71 species of gastropods, 2200 individuals to 42 species of bivalves and 362 individuals to 5 species of scaphopods. Neobuccinum eatoni with 89 individuals, Genaxinus debilis with 674 individuals and Dentalium majorinum with 159 individuals were the most abundant species of gastropods, bivalves and scaphopods, respectively. Of the total cited species, six new records are added for the South Shetland Islands, 30 for the Western Antarctic Peninsula, 34 for the Bellingshausen Sea and 30 for Peter I Island. On the other hand, new bathymetric records are given for 44 species in Antarctic waters