Acanthocephalan infection of inshore fish in two fjords at South Georgia

An examination of 111 fish of eight species, including 92 immature Notothenia rossii Richardson revealed nine acanthocephalan species, including four Echinorhynchida occurring in the alimentary tract and five Polymorphida in the body cavity. Echinorhynchida were much more numerous (87% specimens of 4855 collected), especially Metacanthocephalus johnstoni Zdzitowiecki (the dominant species) and Aspersentis megarhynchus (Linstow). The Polymorphida parasites of seals (three species) were more abundant than species parasitic in birds (two species). Association of most of species, (except Corynosoma bullosum (Linstow) and Echinorhynchus spp.), with the inshore (fjord) environment was confirmed. The species diversity, prevalence and density of infection increased with the size of immature N. rossii. Differences in acanthocephalan occurrence and changes with time are related to differences in host distribution and abundance. For example, the occurrence of C. arctocephali in N. rossii at South Georgia is related to the increase of the fur seal population. A list of acanthocephalans in fish at South Georgia and the South Shetland Islands (14 species in total) is included

Acanthocephalan infection of inshore fishes at the South Orkney Islands

An examination of notothenioid fish of three species, including 23 immature Notothenia coriiceps Richardson, revealed seven acanthocephalan species, including two Echinorhynchida occurring in the intestine and five Polymorphida in the body cavity. Four species -Metacanthocephalus johnstoni Zdzitowiecki, Corynosoma arctocephali Zdzitowiecki, C. pseudohamanni Zdzitowiecki, C.shackletoni Zdzitowiecki - are reported for the first time from the area. Polymorphida were twice as numerous as Echinorhynchida. The dominant parasites were Aspersentis megarhynchus (Linstow) and C. hamanni (Linstow) in Notothenia coriiceps, and C. bullosum (Linstow) in Chaenocephalus aceratus (Lönnberg). The infection of Notothenia coriiceps and Chaenocephalus aceratus in this area was compared with these species and Notothenia rossii Richardson in neighbouring areas. The infection of Notothenia coriiceps at the South Orkney Islands is more similar to that at the South Shetland Islands than that found at South Georgia