In total, 18 species and larval forms of endoparasitic worms were found in 19 newly examined notothenioid fishes of three species, Trematomus hansom, Notothenia coriiceps and Chionodraco hamatus, caught off Adelie Land. One digenean species, Neolepidapedon trema-tomi, was recorded in this area for the first time. A total list of endoparasitic worms prepared by Zdzitowiecki etal. (1998) increased from 20 to 21 species and larval forms and concerns 11 determined and one determined species of Digenea (the most diverse group), three larval forms of Cestoda, three species (one identified only to genus) of Acanthocephala, two species (one in the larval stage) and one larval form of Nematoda. All these species and forms, with the exception of the indetcrmined digenean, occur also in the deep Antarctica, in the Ross Sea and/or in the Weddell Sea. The prevalence and relative density of infection with each parasite in three host species is given based on summarized previous and new data.
A total of 704 fishes representing 39 species were examined. Twenty five digenean species were recognized. Only one species previously found by the present author in a fiord of this area was absent in the material. Pelagic species were usually not parasitized by digeneans, while demersal fishes were normally found to be infected. Results of the present study are compared to those from fiords. Seven species were found to be widely distributed. Two of them, Macvicaria pennelli and Genolinea bowersi, were associated with an inshore fiord environment and could be used as biological tags indicating the association of hosts with this kind of environment. Three of widely distributed species, Lepidapedon garrardi, Elytrophalloides oatesi and Lecilhaster macrocotyle, were not clearly associated with any environment.
Gonocerca phycidis, Neolebouria antarctica and other less widely distributed species, with the exception of Postmonorchis variabilis, were associated with deep part of fiords and/or open sea shelf environment. The level of infection of open sea fish at the South Shetlands was low. Many fish species living at South Georgia were massively infected; the dominant species in this area is E. oatesi, which was rare off the South Shetland Islands. A total of 45 digenean species occurring in the Antarctic fish were listed. Eleven of them were not endemic.
The paper comprises the review of all 23 known valid species along with synonyms and polytomic keys based on morphological features. Mature specimens of 8 species occur in fishes, 4 in birds, 11 in mammals. Each species settles in a definite section of the digestive tract. The structure of a population is dependent upon the time which has passed since the moment of invasion and the intensity of infestation. Acathocephalans can be found in hosts all the year round, but incomplete seasonality of the occurrence of 2 fish parasites has been recorded. Fish parasites show wide specificity in relation to the hosts mentioned while bird and mammal parasites specificity is narrow. The majority of acanthocephalan species have circumpolar distribution but only 3 have been found inside the polar circle and the other 7 are common in the environs of subcontinental archipelagoes. Acanthocephalans do not yield precedence as far as the diversity of species and infestation intensity are concerned in the Antarctic to other groups of parasite helminths. Their great importance results from their mass occurrence in the vertebrates which are the focus of. man's practical interests — fishes, seals and whales.
104 specimens of notothenioid fishes of five species (Patagonotothen longipes, P. tessellata, Champsocephalus esox, Cottoperca trigloides and Patagonotothen brevicauda) caught at two sites in the Beagle Channel (Magellanic sub-region, sub-Antarctica) were examined for the presence of thorny-headed worms (Acanthocephala). Representatives of three fish species, Patagonotothen longipes, P. tessellata, and Champsocephalus esox, were infected. Fishes caught at the eastern mouth of the channel were infected with 180 echinorhynchids representing three species, Aspersentis johni (the most numerous species), Heterosentis heteracanthus, and Hypoechinorhynchus magellanicus, and only 12 cystacanths of four polymorphids, Andracantha baylisi, Corynosoma sp., Corynosoma beaglense, and Corynosoma evae. Patagonotothen longipes was the most highly infected in the eastern mouth of the channel (prevalence 85%, maximum intensity 26). Aspersentis johni was the dominant parasite species in this host (prevalence 85%, mean abundance 4.00, maximum intensity 18) and H. heteracanthus was the sub-dominant one (prevalence 50%, mean abundance 2.60, maximum intensity 25). The infections of C. esox were the most diverse (six parasite species - three echinorhynchids and three polymorphids). Fish caught near the city of Ushuaia were infected only with six cystacanths of C. evae (intensity one). Taking into account the whole sample, C. evae was the most abundant polymorphid, represented by 10 of 18 specimens found. Three species, H. heteracanthus, A. baylisi and C. evae, have been previously reported from the low western Antarctic (H. heteracanthus also from the Kerguelen sub-region of sub-Antarctic), remaining four species seem to be endemics of the Magellanic sub-region of sub-Antarctic.
In total, 8511 amphipods of 12 species caught in Admiralty Bay were examined for the presence of acanthocephalans using them as intermediate hosts. Only 27 specimens of eight species were infected (total prevalence 0.32%). Acanthellae and cystacanths of four species using fishes as either definitive or paratenic hosts were found. Normally, single parasites occurred; in one case two acanthocephalans were present in one specimen of Bovallia gigantea. This host species was the most strongly infected, with the prevalence 3.41%. Six other amphipod species were infected with the prevalence 0.08-0.66%. One of two Jassa ingens examined was also infected. Over 50% of acanthocephalans belonged to one echinorhynchid species maturing in fishes, Aspersentis megarhynchus, which occurred in five host species of four amphipod families, B. gigantea, Gondogeneia antarctica, J. ingens, Hippomedon kergueleni and Orchomenella rotundi-frons. Two polymorphid species maturing in seals, Corynosoma hamanni and C. pseudohamanni, were found in a single host species each, Prostebbingia brevicornis and Cheirimedon femoratus, respectively. Three parasite species mentioned occurred exclusively in sublittoral host species, at the depth 0-30 m. The third polymorphid species, C. bullosum, was the only species occurring in the amphipod, Waldeckia obesa, living in the deeper water (infected specimen was caught at the depth 60 m), but was found also in B. gigantea. Differences between infections of Amphipoda and fishes with echinorhynchids and polymorphids are discussed.
The infections of four fish species, Trematomus newnesi, T. bernacchii, Lindbergichthys nudifrons and Harpagifer antarcticus with parasitic worms, in the coastal zone off the Vernadsky Station (Argentine Islands, West Antarctica) are described. Data on infections are compared with previous results from Admiralty Bay at the South Shetland Islands. Indices of infection are for each host-parasite relationship. In total, 16 taxa of parasites were recorded: 6 digeneans, 3 larval cestodes, 4 (adult and cystacanth) acanthocephalans, and 3 (adult and larval) nematodes. Fifteen of them have been previously recorded in Notothenia coriiceps from this area. Hence, the number of parasitic taxa recorded in this region increased from 21 to 22. Either the digenean Macvicaria georgiana or acanthocephalan Corynosoma pseudohamanni were dominants in different hosts. Trematomus bernacchii was the most strongly infected, especially with M. georgiana (prevalence 100%, mean abundance 113.7). The infection parameters of the majority of parasites were lower at the Vernadsky Station than in the Admiralty Bay, especially for host-parasite relations with larval cestodes and nematodes. The presently reported study have confirmed that the southern range of distribution of two acanthocephalans, Aspersentis megarhynchus and Corynosoma hamanni extends south to the area near the Argentine Islands.
Thirty four specimens of bony fishes (5 species) and four specimens of skates (2 species) were examined. Skates were infected with adult representatives of Phyllobothrium sp. (Tetraphyllidea) and Macrobothridium sp. (Diphyllidea). Bony fishes were infected with three morphological forms of tetraphyllidean cercoids (with mono- and bilocular bothridia, and bothridia undivided with hook-like projections), diphyllobothrid plerocercoids and one pseudophyllidean species, Bothriocephalus antarcticus sp.n. This species, as well as two species found in skates, seems to be endemic for the Kerguelen subregion.
Trematomus newnesi (Nototheniidae), a bentho-pelagic fish, caught off Adélie Land (eastern Antarctic) was examined for the presence of internal parasitic worms. These fishes were infected with 11 species and larval forms of parasites: Digenea (Macvicaria pennelli, Neolebouria terranovaensis, Genolinea bowersi, and Elytrophalloides oatesi), larval Cestoda (two forms of tetraphyllidean metacestodes, bilocular form and trilocular form, and diphyllobothriid plerocercoids), Acanthocephala (Metacanthocephalus campbelli, M. johnstoni) and larval Nematoda (Contracaecum osculatum, C. radiatum). Larval cestodes were the dominant parasites, whereas acanthocephalans were relatively rare. Five species and larval forms were recorded also in fish caught in the Davis Sea. A check list of parasites of T. newnesi recorded in the eastern- and western Antarctic comprises 21 species and larval forms. Probably, T. newnesi plays an important role in life cycles of parasitic worms in the Antarctic.
The aim of this study was to assess the anisakid nematode distribution pattern in the fish collected from the South Shetland Islands . A total of 32 fish species were examined for the presence of nematodes in 1978, 1979, 1981 and 2007/2008. The fish were caught off the South Shetland Islands ( Elephant Island , Shishkov Island and in Admiralty Bay – King George Island ). Three genera of L3 larval nematodes were identified: Anisakis sp., Contracaecum spp. and Pseudoterranova decipiens. The infection level was higher on the shelf around the islands than in Admiralty Bay . This is explained by a higher abundance of the final hosts in the region. A comparison of the infection data from 1978/79 and 2007/2008 with data from 1994/96 (Palm et al. 1998, 2007) was done. The parameters of infection of Notothenia coriiceps and Lepidonotothen nudifrons by Pseudoterranova decipiens were decreasing within the 30 years period.
The two bathydraconid species, Gymnodraco acuticeps and Cygnodraco mawsoni, caught in the Ross Sea (Antarctic summer 2002) were examined for internal parasites. All specimens (four G. acuticeps and one C. mawsoni) were infected. G. acuticeps harboured larval Cestoda (bilocular tetraphyllidean cercoids, diphyllobothriid plerocercoids) and Nematoda (Contracaecum spp.), acanthocephalan cystacanths and adult helminths (three species of Digenea and one species of Nematoda). Two specimens of C. mawsoni (including data from one additional specimen examined earlier) were infected by larval Cestoda (bilocular cercoid) and Nematoda (Contracaecum spp.) and adult helminths (three species of Digenea and one species of Nematoda). The present data are compared and discussed with the relevant literature data.