Diversity of epibenthic habitats of gammaridean amphipods in the eastern Weddell Sea

Gammaridean amphipods appear ubiquitous in the shelf communities of the eastern Weddell Sea where more than 230 species have been recorded. Comparison of catches of the 40 most common species taken by different gears and ethological observations in the aquarium allowed us to distinguish 6 groups: endobenthic, epibenthic, hyperbenthic (or suprabenthic), benthopelagic, pelagic and cryopelagic. Only epibenthic species, which form the bulk of the fauna, are dealtwith in the present paper. Aquarium observations indicated three different epibenthic strata occupied by amphipods: the sediment surface, and a lower and upper level on the substrata formed by sessile suspension feeders. In addition, four symbiotic microhabitats were detected in or on sponges, ascidians, hydrozoans and gorgonians.