scholarly journals Age and growth of Scotia Sea icefish, Chaenocephalus aceratus, from the South Shetland Islands

2004 ◽  
Vol 16 (3) ◽  
pp. 253-262 ◽  
Author(s):  
M. LA MESA ◽  
J. ASHFORD ◽  
E. LARSON ◽  
M. VACCHI
Keyword(s):  
Sagittal Plane ◽  
Growth Curves ◽  
Age And Growth ◽  
South Shetland Islands ◽  
Trawl Survey ◽  
Growth Data ◽  
The South ◽  
Randomized Sampling ◽  
Shetland Islands ◽  
Chaenocephalus Aceratus

Samples of Chaenocephalus aceratus (Lönnberg) were collected during a trawl survey carried out around the South Shetland Islands in January–February 2002. Fish were caught by commercial bottom trawl fishing down to 500 m depth, using a stratified randomized sampling design. As observed in other recent surveys within the same area, C. aceratus represented one of the predominant species. Overall, 357 specimens ranging from 13 and 67 cm (TL) were selected for the present study. Ages were estimated by counting annuli present in the sagittal otoliths, exposed by grinding and polishing along their sagittal plane. To estimate the precision of age data, we compared blind readings by readers from different institutions. The age range was 1–17 years for females and 1–15 years for males. Von Bertalanffy growth curves were fitted to the estimated age-length data for each sex. The estimated values of asymptotic length L∞ (cm) and K (year−1) were respectively 79.8 and 0.07 for females and 60.0 and 0.09 for males. The growth performance index ranged between 2 and 2.5, similar to that reported in other icefish. Sexual maturity was attained by females and males at about 10 and 9 years old respectively, at about 60% of their maximum estimated age. These results are compared with age and growth data available in the literature for C. aceratus, and discussed in the light of recent commercial exploitation.

Acanthocephalan infection of inshore fishes at the South Orkney Islands

1996 ◽  
Vol 8 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Krzysztof Zdzitowiecki ◽  
Martin G. White
Keyword(s):  
Body Cavity ◽  
The Body ◽  
South Shetland Islands ◽  
The South ◽  
Shetland Islands ◽  
Orkney Islands ◽  
Notothenia Coriiceps ◽  
South Orkney Islands ◽  
Chaenocephalus Aceratus ◽  
First Time

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.

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
Keyword(s):  
Mature Female ◽  
South Shetland Islands ◽  
The South ◽  
Admiralty Bay ◽  
Shetland Islands ◽  
South Georgia ◽  
Orkney Islands ◽  
Open Sea ◽  
South Orkney Islands ◽  
Chaenocephalus Aceratus

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.

scholarly journals Small unmanned aerial vehicles for aeromagnetic surveys and their flights in the South Shetland Islands, Antarctica

Polar Science ◽  
2014 ◽  
Vol 8 (4) ◽  
pp. 342-356 ◽  
Author(s):  
Minoru Funaki ◽  
Shin-Ichiro Higashino ◽  
Shinya Sakanaka ◽  
Naoyoshi Iwata ◽  
Norihiro Nakamura ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
South Shetland Islands ◽  
The South ◽  
Shetland Islands ◽  
Aerial Vehicles
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