New data on the occurrence of Acanthocephala in Antarctic Amphipoda

In total, 6401 amphipods, including 5707 Cheirimedon femoratus, caught at the Galindez Island (Argentine Islands, Western Antarctica) were examined for the presence of cystacanths and advanced acanthellae of Acanthocephala. Two parasite species, Corynosoma pseudohamanni Zdzitowiecki, 1984 and Metacanthocephalus johnstoni Zdzitowiecki, 1983, were found in the haemocoeloma of C. femoratus. Total prevalence was 1.19%, that of C. pseudohamanni 0.68% and of M. johnstoni 0.51%. Additionally, 8 of 1416 C. femoratus caught in the Admiralty Bay (South Shetland Islands) were found to be infected with C. pseudohamanni and free of M. johnstoni. The representative of the genus Metacanthocephalus was found in the intermediate host for the first time. C. pseudohamanni was more abundant at the Galindez Island (prevalence 0.68%) than in the Admiralty Bay (prevalence 0.42% in previous investigations and 0.56% in present ones). Amphipods harboured usually one or rarely two acanthocephalans of one species. Both parasites were more abundant in amphipods caught in the polluted water closely to the Vernadsky Station than in the Mick Channel, farther from the station (prevalence 0.77% vs. 0.51% for C. pseudohamanni and 0.64% vs. 0.26% for M. johnstoni).