Polychaetes of the shallow sublittoral of Admiralty Bay, King George Island, South Shetland Islands

Abstract

Twenty five species of Polychaeta were recorded in soft bottom samples collected from 4–30 m. Total abundance of polychaetes ranged from 60 to 3300 m^-2. High abundance values were locally recorded for Microspio moorei, Tharyx epitoca and Ophelina syringopyge. These species, together with more regularly distributed Capitella capitata and Scoloplos marginatus, constituted over 70% of all specimens. Total biomass value of the polychaetes varied between 3.8 and 46.4 gm^-2. Travisia kerguelenensis and Aglaophamus ornatus constituted over 75% of total biomass. Species composition, richness and diversity of the polychaete assemblage varied with depth. Two parts of the investigated bottom section, differing in the polychaete assemblages structure, were distinguished; the first one in the depth range from 4–20 m and the second one at the depths of 25–30 m. On the basis of both new and previously published data two types of polychaete assemblages of the shallow soft bottom of the Antarctic sublittoral were distinguished. The type of sediment seems to be the main factor influencing the composition of polychaete assemblages.