Benthic polychaetes off Edward VIII Plateau in the continental shelf of East Antarctica

The benthic fauna of the shelf off East Antarctica is relatively unexplored, when compared to regions like the West Antarctic Peninsula and Ross Sea. The continental shelf of Antarctica is unusually deep (average depth 450 m) and in some places as wide as 125 km. Though this shelf covers a vast area (nearly 11.4% of the world continental shelf area), baseline information on species occurrence in this region was very poor until recently. Under the auspices of the Census of Antarctic Marine Life (CAML), International Polar Year (IPY) and the Scientific Committee on Antarctic Research Marine Biodiversity Information Network (SCAR-MarBIN), taxonomic lists of species recorded in the Southern Ocean have been compiled to form the Register of Antarctic Marine Species (RAMS), which currently includes over 1.02 million records of 10,042 species. Among the marine benthos, over 4100 species have been described from the Antarctic continental shelf alone 4, . Availability of datasets from such databases has enabled several attempts to define the biogeography of the Antarctic shelf. A zoogeographic zonation based on peracarid crustaceans revealed that the East Antarctic region harbours highest species richness for this group. Based on richness of gastropod and bivalve molluscs, Linse et al. and Clarke et al. were able to subdivide this wide region (0°-170° E) into three sub regions, viz. Dronning Maud Land (0°-45°E), Enderby Land (45°E-55°E) and Wilkes Land (55°E-170°E). An unusually high richness of molluscs has been reported from off Enderby Land.