The biology of the bigeye grenadier at South Georgia
The biology of the bigeye grenadier Macrourus holotrachys caught as by-catch in the Patagonian toothfish Dissostichus eleginoides longline fishery conducted around South Georgia was investigated to improve data available for fisheries management. Age estimates suggest that M. holotrachys is a modera...
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2004
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ftnerc:oai:nora.nerc.ac.uk:10215 2023-05-15T17:54:44+02:00 The biology of the bigeye grenadier at South Georgia Morley, S.A. Mulvey, T. Dickson, J. Belchier, M. 2004 http://nora.nerc.ac.uk/id/eprint/10215/ unknown BLACKWELL PUBLISHING LTD Morley, S.A. orcid:0000-0002-7761-660X Mulvey, T.; Dickson, J.; Belchier, M. 2004 The biology of the bigeye grenadier at South Georgia. Journal of Fish Biology, 64 (6). 1514-1529. Biology and Microbiology Publication - Article PeerReviewed 2004 ftnerc 2023-02-04T19:26:36Z The biology of the bigeye grenadier Macrourus holotrachys caught as by-catch in the Patagonian toothfish Dissostichus eleginoides longline fishery conducted around South Georgia was investigated to improve data available for fisheries management. Age estimates suggest that M. holotrachys is a moderately slow growing species (K = 0.10), reaching ages of >30 years and attaining total lengths (L-T) >80 cm (L-infinity = 33). The size at which 50% of females had started to mature (L-int50) for M. holotrachys was 21 cm pre-anal length (L-PA) and occurred at c. 9 years old. Estimates of natural mortality and Pauly's growth performance index were found to be low (M = 0(.)09 and Phi = 2.82 respectively). Gonad maturity stage was described from macroscopic and histological investigation. Mature ovaries had oocytes at all developmental stages with between 22 and 55% likely to be spawned each year. Absolute fecundity ranged from 22 000 to 260 000 eggs and was positively correlated with both pre-anal length and mass. A highly skewed sex ratio of 32 : 1, females: males, was found for specimens caught by longlines but not for a small sample of shallower trawl-caught specimens. It is suggested that females are far more susceptible to longline capture than males. Macrourus holotrachys is a bentho-pelagic predator and scavenger that feeds on a wide range of fishes and invertebrates. The fish are long lived, slow-growing species typical of deep-water grenadiers; fisheries management strategies should reflect their probable susceptibility to overfishing. (C) 2004 The Fisheries Society of the British Isles. Article in Journal/Newspaper Patagonian Toothfish Natural Environment Research Council: NERC Open Research Archive |
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Natural Environment Research Council: NERC Open Research Archive |
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Biology and Microbiology |
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Biology and Microbiology Morley, S.A. Mulvey, T. Dickson, J. Belchier, M. The biology of the bigeye grenadier at South Georgia |
topic_facet |
Biology and Microbiology |
description |
The biology of the bigeye grenadier Macrourus holotrachys caught as by-catch in the Patagonian toothfish Dissostichus eleginoides longline fishery conducted around South Georgia was investigated to improve data available for fisheries management. Age estimates suggest that M. holotrachys is a moderately slow growing species (K = 0.10), reaching ages of >30 years and attaining total lengths (L-T) >80 cm (L-infinity = 33). The size at which 50% of females had started to mature (L-int50) for M. holotrachys was 21 cm pre-anal length (L-PA) and occurred at c. 9 years old. Estimates of natural mortality and Pauly's growth performance index were found to be low (M = 0(.)09 and Phi = 2.82 respectively). Gonad maturity stage was described from macroscopic and histological investigation. Mature ovaries had oocytes at all developmental stages with between 22 and 55% likely to be spawned each year. Absolute fecundity ranged from 22 000 to 260 000 eggs and was positively correlated with both pre-anal length and mass. A highly skewed sex ratio of 32 : 1, females: males, was found for specimens caught by longlines but not for a small sample of shallower trawl-caught specimens. It is suggested that females are far more susceptible to longline capture than males. Macrourus holotrachys is a bentho-pelagic predator and scavenger that feeds on a wide range of fishes and invertebrates. The fish are long lived, slow-growing species typical of deep-water grenadiers; fisheries management strategies should reflect their probable susceptibility to overfishing. (C) 2004 The Fisheries Society of the British Isles. |
format |
Article in Journal/Newspaper |
author |
Morley, S.A. Mulvey, T. Dickson, J. Belchier, M. |
author_facet |
Morley, S.A. Mulvey, T. Dickson, J. Belchier, M. |
author_sort |
Morley, S.A. |
title |
The biology of the bigeye grenadier at South Georgia |
title_short |
The biology of the bigeye grenadier at South Georgia |
title_full |
The biology of the bigeye grenadier at South Georgia |
title_fullStr |
The biology of the bigeye grenadier at South Georgia |
title_full_unstemmed |
The biology of the bigeye grenadier at South Georgia |
title_sort |
biology of the bigeye grenadier at south georgia |
publisher |
BLACKWELL PUBLISHING LTD |
publishDate |
2004 |
url |
http://nora.nerc.ac.uk/id/eprint/10215/ |
genre |
Patagonian Toothfish |
genre_facet |
Patagonian Toothfish |
op_relation |
Morley, S.A. orcid:0000-0002-7761-660X Mulvey, T.; Dickson, J.; Belchier, M. 2004 The biology of the bigeye grenadier at South Georgia. Journal of Fish Biology, 64 (6). 1514-1529. |
_version_ |
1766162539186487296 |