Distribution and diversity of cumacean assemblages in Admiralty Bay, King George Island

Abstract

Distribution and diversity of cumacean assemblages in Admiralty Bay, King George IslandEleven species of cumaceans were found in 105 samples collected in Admiralty Bay (King George Island) in the summers of 1984/85 and 1985/86, from 20 to 500 m depth range. Four cumacean assemblages were distinguished using the multivariate analysis. They were characterized by the dominance of one or two species often with low density values. Two assemblages were found in open waters of Admiralty Bay. The first inhabited on sandy-clay-silt and silty-clay-sand bottom deposits in the depth range from 140 to 330 m, withCampylaspis maculata(1.6 ± 2.1 ind./0.1m2; F = 72.4%) andLeuconsp. (1.4 ± 1.6 ind./0.1m2; F = 68.9%) as key species. The second assemblage was found in the depth range from 50 to 120 m with silty-sand sediments, and it was characterized by the presence of Vauthompsonia inermis (6.5 ± 6.6 ind./0.1m2; F = 92.0%). A third assemblage was found in shallow waters influenced by glaciers in the bottom area of Ezcurra Inlet. It was characterized by sandy-clay-silt sediments and the presence ofEudorella splendida(14.6 ± 9.4 ind./0.1m2; F = 100.0%) as a core species. The last assemblage was found in the shallow sublittoral (50-100 m) of Ezcurra Inlet and the central basin, withDiastylis anderssoni armata(1.5 ± 1.1 ind./0.1m2; F = 85.7%) andDiastylopsis goekei(1.1 ± 1.0 ind./0.1m2; F = 71.4%) as the most frequent and abundant species.V. inermisis considered a eurytopic species with high frequency in the whole material, and was present in all four distinguished assemblages.E. splendidaandD. goekeiwere also recorded in each of the assemblages, but their total frequency was lower.