Changes in acanthocephalan infection of the Antarctic fish Notothenia coriiceps in Admiralty Bay, King George Island, over 29 years

Abstract

Changes in acanthocephalan infection of the Antarctic fishNotothenia coriicepsin Admiralty Bay, King George Island, over 29 yearsA comparison between the levels of infection with Acanthocephala of the fishNotothenia coriicepsin Admiralty Bay (South Shetland Islands, Antarctic) in 1978/79 and 2007/08 is presented. The same eight acanthocephalan species, three echinorhynchids maturing in fish,Aspersentis megarhynchus(dominant species),Metacanthocephalus johnstoni(subdominant species) andM. dalmori(common species), and five polymorphids maturing in mammals and birds,Corynosoma hamanni, C. pseudohamanni(both co-dominant species),C. arctocephaliandC. bullosum(both common species), andC. shackletoni(rare species), were found. Echinorhynchids were more numerous in 2007/08 (mean abundance 46.54 versus 35.35 in 1978/79), whereas polymorphids more numerous in 1978/79 (mean abundance 74.35versus36.40 in 2007/08). The overall results therefore demonstrated that echinorhynchids were more numerous than polymorphids in 2007/08 and the reverse was true in 1978/79. This situation is dependent mainly upon the decreased infections withC. hamanni, C. pseudohamanniandC. bullosum, and to a lesser degree upon the increasing of infections withM. johnstoni.The decrease of the threeCorynosomaspp. is possibly associated with the decreasing of populations of final hosts, seals, on the shore of Admiralty Bay in the vicinity ofArctowskiStation.