Krzysztof Zdzitowiecki

Fish populations of Port Foster, Deception Island, Antarctica and vicinity

The fish populations of Port Foster, Deception Island, South Shetland Islands, Antarctica, were investigated as part of the Erupt Antarctic ecosystem study. Surveys were conducted on five cruises between March 1999 and November 2000. Samples also were collected off Livingston Island and King George Island of the South Shetland Islands. Specimens were collected or observed using a multiple opening and closing net and environmental sampling system, otter trawls, benthic line-transect photography, and remotely operated vehicle video. Species composition, length, weight, reproductive condition, diet, habitat, and parasitic infestation were examined for the dominant fish species. Eleven species were collected, all in the suborder Notothenioidei. The fishes found in the survey are known to occur in the region and had diets similar to those found in other studies. Abundances of demersal fishes in Port Foster ranged from 0.05 to 0.10 individuals m−2 over the study period. Inshore shallow-water ( 30 m) habitats are identified in Port Foster and described. Port Foster may be a refuge for juvenile fishes such as Champsocephalus gunnari. Limited exchange with the surrounding waters also may limit the influence of recruitment and prey abundance fluctuations outside Port Foster. Trematomus scotti had heavy body cavity parasite infestation from Port Foster, possibly due in part to decreased benthic scour from large icebergs, allowing benthic parasites to persist.

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).

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)

Antarctic representatives of the genus Macvicaria Gibson & Bray, 1982 (Digenea Opecoelidae), with descriptions of two new species.

Four species of marine fish digeneans, Macvicaria pennelli (Leiper & Atkinson, 1914), M. ophthalmolyci n. sp., M. muraenolepidis n. sp. and M. antarctica (Kovaljova & Gaevskaya, 1974) n. comb., are described. The digeneans were collected in the western Antarctic (the environs of South Georgia and the South Shetland Islands) and in the sub-Antarctic (east of the Falkland Islands). The species described differ from each other in body shape, position of the ventral sucker, sucker ratio, posterior extent of the cirrus-sac, arrangement of the vitelline follicles and dimensions of the eggs. M. muraenolepidis n. sp. is restricted to the gadiform fish Muraenolepis microps. M. pennelli and M. antarctica were found exclusively in notothenioid fishes. M. ophthalmolyci n. sp. was found in zoarcid and nototheniid fishes. Previous authors have recorded only one of these species, M. pennelli, from the eastern Antarctic, but it is probable that more than one species was represented in their collections.

Diversity of Digenea, Parasites of Fishes in Various Areas of the Antarctic

A critical list of the Antarctic fish Digenea recently published [1] concerns 36 species. However, a genuine occurrence of one species, Lecithocladium falklandicum, in the Antarctic is doubtful. A validity of another one, Gonocerca lobata, is questionable. These two species are omitted from the present review. On the other hand, new material collected in the Weddell Sea has recently been reported by the present author and a further ten undescribed species were recognized. Their descriptions have been recently published or are in press [2, 3, 4, 5, 6, 7]. Thus 44 species are taken into account. This is not a final number of digeneans occurring in fish in the Antarctic, as strongly contracted and/or damaged undeterminable (even to generic level) specimens of not less than two further species are in the present author’s collection. The presence of further undescribed species is very possible, as only limited data are available for parasites of Antarctic fishes of such important families as Liparididae, Zoarcidae, Murenolepididae and Macrouridae, as well as some Notothenioidei like Artedidraconidae and Bathydraconidae occurring in deep waters. It should be noted that only one species, Lecithochirium whitei, is known as a parasite specific to a bathypelagic fish, Bathylagus antarcticus. All others normally occur in benthic and bentho-pelagic fishes; only a few species and specimens have been reported also from pelagic fishes.

Description of a New Digenean (Zoogonidae) Genus and Species from Sub-Antarctic Fish Patagonotothen tessellata

Abstract Whitegonimus ozoufae n. gen., n. sp. (Digenea: Zoogonidae) is reported from the stomach of Patagonotothen tessellata in the harbor of Ushuaia in the Beagle Channel (Tierra del Fuego, Argentina) at a depth of 7–9 m. The female genital system structure indicates the new taxon belongs in the subfamily Lepidophyllinae (Zoogonidae). None of the genera previously described is similar to the new genus. The most important taxonomic features are the spined tegument, lack of enlarged circumoral spines, gonads arranged in tandem, long caeca, vitelline follicles extending from the level of the ventral sucker to the posterior end of anterior testis, and a Y-shaped excretory vesicle. Only 3 genera, Overstreetia, Anarhichotrema, and Pseudopalaeorchis, have testes arranged in tandem, but they differ from the new genus in possessing enlarged circumoral spines, oral sucker size, esophagus length, length of caeca, vitellaria restricted to hindbody, the form of the ovary, and an I-shaped excretory vesicle.

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 (Lonnberg). 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.

Digenean Trematoda infection of inshore fish at South Georgia

A sample of 111 fish of eight species caught in two fjords at South Georgia were examined for digenean trematode parasites. The alimentary tracts of all specimens were infected with digeneans. The dominant species was Elytrophalloides oatesi (Leiper & Atkinson) which was found in all fish, with a maximum number of 1961 specimens per fish. Other common species were; Macvicaria pennelli (Leiper & Atkinson), Lepidapedon garrardi (Leiper & Atkinson), Lecithaster macrocotyle Szidat & Graefe, Genolinea bowersi (Leiper & Atkinson) and Postmonorchis variabilis Prudhoe & Bray. Three further species, Neolebouria antarctica (Szidat & Graefe), Discoverytrema markowskii Gibson and Gonocerca phycidis Manter, were rare. Infection of the most commonly caught fish at South Georgia, Notothenia rossii Richardson, is compared with that of N. rossii at Admiralty Bay, South Shetland Islands. The species composition of common parasites was similar in both areas but conspicuous differences in the frequency of individual digenean species were found.

Description of a New Opecoelid Trematode Species from Nototheniid Fish in the Beagle Channel (Sub-Antarctica)

Abstract: Macvicaria magellanica n. sp. (Digenea: Opecoelidae) is the third representative of this genus occurring in fish in the Magellanic sub-region of sub-Antarctica and the first one found in sub-coastal waters in this area (the Beagle Channel). Its main taxonomic features include an elongate body, oral:ventral sucker ratio based on widths of 1.0:1.52–1.98, cirrus sac reaching to level of posterior half of the ventral sucker, testes arranged in tandem, numerous vitelline follicles divided into 2 groups separated by a gap parallel to the ventral sucker, vitelline follicles dorsally not confluent at the uterus and gonads, and egg dimensions of 40–51 × 25–32 μm. The most similar species is Macvicaria antarctica, but it differs from the newly described species in having vitelline follicles dorsally confluent at the level of the uterus and by occurring in fish associated with the Falkland–Patagonian shelf at greater depths (at the North Scotia Ridge, 300–500 m). A key to 9 Antarctic and sub-Antarctic species of Macvicaria is included.

Boreascotia megavesicula n. g., n. sp. (Digenea: Hemiuridae: Lecithochiriinae) in the nototheniid fish Lepidonotothen macrophthalma (Norman) from the sub-Antarctic Atlantic.

Boreascotia megavesicula n. g., n. sp. is described from the intestine of the fish Lepidonotothen macrophthalma from the North Scotia Ridge, Sub-Antarctic, Atlantic Ocean. The new genus has an ecsoma, placing it in the family Hemiuridae, and a distinct prostatic vesicle, placing it in the subfamily Lecithochiriinae, but is distinct from the other members of the subfamily in having an elongate, tubular seminal vesicle, which reaches well into the hindbody and overlaps the anterior testis.