scholarly journals Contribution to the knowledge of the infection with Acanthocephala of a predatory Antarctic ice-fish Chaenocephalus aceratus

2010 ◽  
Vol 31 (4) ◽  
pp. 303-308 ◽  
Author(s):  
Zdzisław Laskowski ◽  
Krzysztof Zdzitowiecki

Contribution to the knowledge of the infection with Acanthocephala of a predatory Antarctic ice-fish Chaenocephalus aceratus Adult females of a predatory fish, the blackfin icefish, Chaenocephalus aceratus examined at the South Shetland Islands and South Orkney Islands were by several orders of magnitude more infected with Acanthocephala than the males and immature females. Such phenomenon has not been observed in the neritic zone at South Georgia. Cystacanths of Corynosoma hamanni and Corynosoma pseudohamanni were the dominant parasites in Admiralty Bay, whereas Corynosoma bullosum was the dominant in the open sea off the South Shetland Islands and South Georgia, and in the sub-coastal waters off the South Orkney Islands. However, the dominance of C. bullosum was observed in several hosts in Admiralty Bay and the co-dominance of C. bullosum, C. hamanni, and C. pseudohamanni in one mature female in the neritic zone at the South Shetland Islands. Probably, these fish previously lived in the open sea. Cystacanths of Corynosoma arctocephali and Corynosoma shackletoni occurred in the fish in Admiralty Bay and off South Georgia. The former parasite was present also off the South Orkney Islands. One cystacanth of Andracantha baylisi was found off South Georgia. Two echinorhynchids, Aspersentis megarhynchus and Metacanthocephalus dalmori, occurred in the alimentary tracts of the fish caught in Admiralty Bay and one specimen of Echinorhynchus petrotschenkoi off the South Shetland Islands. The highest infection, amounting to 816 acanthocephalans, was found in a mature female in Admiralty Bay. One cystacanth of C. hamanni occurred in a single immature fish caught in the sub-coastal area off Deception Island.

1996 ◽  
Vol 8 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Krzysztof Zdzitowiecki ◽  
Martin G. White

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.


2018 ◽  
Vol 8 (21) ◽  
pp. 10520-10529 ◽  
Author(s):  
Maria P. Dias ◽  
Ana Paula Bertoldi Carneiro ◽  
Victoria Warwick-Evans ◽  
Colin Harris ◽  
Katharina Lorenz ◽  
...  

1991 ◽  
Vol 3 (1) ◽  
pp. 53-59 ◽  
Author(s):  
L.B. Minto ◽  
G.J. Shepherd ◽  
M.B. Usher

Halozetes belgicae is distributed widely in the Subantarctic and maritime Antarctic, with subspecies described from Macquarie Island and the South Sandwich Islands. A morphometrical study, based largely on the development of the setae, indicates that the nominate subspecies is confined to the Antarctic Peninsula and its offshore islands (including the South Shetland Islands), whilst specimens from the South Orkney Islands are probably consubspecific with individuals on the South Sandwich Islands. In comparison with other studies of the Acari, the results strengthen the case for the recognition of a South Orkadian biogeographical zone.


1977 ◽  
Vol 7 (2) ◽  
pp. 268-282 ◽  
Author(s):  
D.E. Sugden ◽  
C.M. Clapperton

Evidence is presented for a more extensive ice cover over South Georgia, the South Orkney Islands, the South Shetland Islands, and the tip of the Antarctic Peninsula. Ice extended across the adjacent submarine shelves to a depth of 200 m below present sea level. Troughs cut into the submarine shelves by ice streams or outlet glaciers and ice-scoured features on the shelf areas suggest that the ice caps were warm-based. The South Shetland Islands appear not to have been overrun by continental ice. Geomorphological evidence in two island groups suggests that the maximum ice cover, which was responsible for the bulk of glacial erosion, predates at least one full glaciation. Subsequently there was a marine interval and then a glaciation which overran all of the lowlying peninsulas. The Falkland Islands, only 2° of latitude north of South Georgia, were never covered by an ice cap and supported only a few slightly enlarged cirque glaciers. This suggests that the major oceanographic and atmospheric boundary represented by the Antarctic Convergence, which is presently situated between the Falkland Islands and South Georgia, has remained in a similar position throughout the glacial age. Its position is probably bathymetrically controlled.


1995 ◽  
Vol 7 (1) ◽  
pp. 37-38 ◽  
Author(s):  
M. Vacchi ◽  
M. La Mesa

A coastal ichthyological survey was carried out in Terra Nova Bay, Ross Sea during the Italian Antarctic Expedition 1987/1988. Vacchi et al. (1992) described the composition of the coastal fish community. Stomach content analysis was conducted on Trematomus bernacchii and T. pennellii to evaluate the trophic overlap (Vacchi et al. 1994). During the survey, several specimens of T. newnesi were caught at 92 m depth. This fish is a coastal species widespread in the high-Antarctic Zone and also known from the South Shetland Islands and the South Orkney Islands (DeWitt et al. 1990). Although T. newnesi was found down to 400 m depth (Tiedtke & Kock 1989), it seems more abundant in very shallow inshore waters (Naito & Iwami 1982, Williams 1988). Andriashev (1970) and Williams(1988) stated T. newnesi was a cryopelagic species associated with the underside of the sea-ice. At Signy Island, T. newnesi was described as semipelagic species eating amphipods (Richardson 1975). Eastman & DeVries (1982) consider it to be both a cryopelagic and benthic species in McMurdo Sound. Targett (1981) found that T. newnesi feeds on krill and plankton at the South Orkney Islands. Planktivory has also been indicated at the South Shetland Islands (Casaux et al. 1990).


1998 ◽  
Vol 55 (4) ◽  
pp. 845-852 ◽  
Author(s):  
I L Boyd ◽  
D J McCafferty ◽  
K Reid ◽  
R Taylor ◽  
T R Walker

This study examined the foraging locations of adult male and female Antarctic fur seals (Arctocephalus gazella) in the Scotia Sea during the postbreeding period. Satellite transmitters were used to track adult males and females and to obtain information about dive depths. Male fur seals migrated away from the breeding area during the postbreeding period whereas females remained close to the breeding grounds and foraged in the same area during two consecutive years. The most intensive foraging by females was associated with the edge of the continental shelf of South Georgia. Males dived deeper than females. Counts of males at South Georgia and at the South Orkney Islands support the result from satellite tracking data showing that males move from South Georgia to the South Orkney Islands at the end of the breeding season. Unlike males, females were limited in their foraging range by the necessity to return to feed dependent young, so breeding sites are likely to be located close to foraging areas that are optimal for females. Locations used for feeding by females were avoided by males, either because they were suboptimal for males or because foraging by females at South Georgia causes local depletion of food, and males, which have the option to forage further afield, can forage more successfully in regions where there are no females. Comparison with fisheries data also suggests that these fur seals are targeting the most abundant exploitable prey.


ZooKeys ◽  
2021 ◽  
Vol 1011 ◽  
pp. 63-71
Author(s):  
Melisa Gañan ◽  
Tamara Contador ◽  
Javier Rendoll ◽  
Felipe Simoes ◽  
Carolina Pérez ◽  
...  

This study provides the summary of the reports of the geographical distribution in the Maritime Antarctic and sub-Antarctic regions of Parochlus steinenii (Gercke, 1889) (Diptera, Chironomidae), the only flying insect occurring naturally in the Antarctic continent. The distribution encompasses the South Shetland Islands (Maritime Antarctic), South Georgia (sub-Antarctic), and parts of the Cape Horn Biosphere Reserve (CHBR, southern Chile). In total 78 occurrence records were identified, 53 from our own records, 19 from the literature, and six from other data present in GBIF. Of the 78 records, 66 are from the South Shetland Islands, eight are from South Georgia, and four from the CHBR. This database was developed as one of the main objectives of two Chilean-funded research projects addressing understanding the effects of climate change on sub-Antarctic and Antarctic insects. It provides dataset documenting the distribution of Parochlus steinenii in the Maritime Antarctic, the sub-Antarctic, and the CHBR in southern South America (Chile). The complete dataset is available in Darwin Core Archive format via the Global Biodiversity Information Facility (GBIF).


2010 ◽  
Vol 58 (4) ◽  
pp. 287-298 ◽  
Author(s):  
Alina María Crelier ◽  
José Roberto Dadon ◽  
Hernán G. Isbert-Perlender ◽  
Daniel Eduardo Nahabedian ◽  
María Cristina Daponte

The distribution pattern, frequency and density (ind./1000 m) of different mesozooplankton species from the South Georgia Islands, South Orkney Islands and the Weddell-Scotia Confluence were analyzed using data obtained in 1994. The maximum densities of the species found were: Eukrohnia hamata (5330), Sagitta gazellae (1052), Clione limacina antarctica (450), Spongiobranchaea australis (375), Clio sulcata (100), Limacina helicina (4076 x 10³), Limacina retroversa (71 x 10(4)), Pelagobia longicirrata (29170), Rhynchonereella bongraini (117), Tomopteris carpenterii (26), Tomopteris planktonis (498), Tomopteris septentrionales (498) and Salpa thompsoni (189). Species density and frequency decreased from South Georgia to the South Orkney Islands, recording intermediate values at the Weddell-Scotia Confluence. Species density in the South Orkney area seemed to be limited by variations in temperature and salinity. The southern area around South Georgia showed the highest density of species, probably due to the influence of the Southern Front of the Antarctic Circumpolar Current. The presence of species characteristic of sub-Antarctic waters such as L. retroversa in the Confluence area could be related to the southward movements of eddies that originate in the Polar Front.


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