Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod
Marine ecosystems are changing; global warming-induced increases in water temperatures and fishing have caused truncated age structures and small sizes at maturity in many stocks. This may affect both populations’ total reproductive output and the link between population demography and recruitment,...
Published in: | Marine Ecology Progress Series |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Inter-Research
2010
|
Subjects: | |
Online Access: | http://hdl.handle.net/11250/108792 https://doi.org/10.3354/meps08486 |
id |
ftimr:oai:imr.brage.unit.no:11250/108792 |
---|---|
record_format |
openpolar |
spelling |
ftimr:oai:imr.brage.unit.no:11250/108792 2023-05-15T14:30:25+02:00 Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod Skjæraasen, Jon Egil Nash, Richard D.M. Kennedy, James Thorsen, Anders Nilsen, Trygve Kjesbu, Olav Sigurd 2010-04-08 application/pdf http://hdl.handle.net/11250/108792 https://doi.org/10.3354/meps08486 eng eng Inter-Research urn:issn:0171-8630 urn:issn:1616-1599 http://hdl.handle.net/11250/108792 http://dx.doi.org/10.3354/meps08486 173-183 404 Marine Ecology Progress Series cod torsk fecundity fertilitet spawning gyting VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 Journal article Peer reviewed 2010 ftimr https://doi.org/10.3354/meps08486 2021-09-23T20:15:04Z Marine ecosystems are changing; global warming-induced increases in water temperatures and fishing have caused truncated age structures and small sizes at maturity in many stocks. This may affect both populations’ total reproductive output and the link between population demography and recruitment, yet detailed information on fecundity regulation is generally lacking for marine fishes. We therefore examined associations between liver energy, oocyte stage, leading cohort oocyte size (LC20), atresia and fecundity for the Northeast Arctic cod (NEAC) Gadus morhua L. from 2006 to 2008 in a comprehensive field and laboratory study. The relationship between the relative liver size (hepatosomatic index, HSI) and specific liver energy content was best described by an asymptotic curve, increasing rapidly at first, then levelling of at HSI > 6%. LC20 increased towards the spawning season, but was also positively associated with total length. At present there is thus a tendency towards larger NEAC females spawning earlier. The incidence of atresia was highest during the advanced yolk granule stage. Only 1% of females that reached an LC20 > 300 µm absorbed all oocytes and thereby aborted spawning. Potential fecundity showed a parabolic relationship with LC20, peaking around 614 µm, i.e. approximately on February 1st, and was positively associated with weight, liver energy and, presently, age. In summary, NEAC females that start vitellogenesis will likely spawn. Atresia and fecundity down-regulation appears only to become pronounced close to spawning. Finally, the size-dependent spawning time, which appears to have emerged in the stock recently, may alter the link between population demography and recruitment. 2015-04-08 Article in Journal/Newspaper Arctic cod Arctic Gadus morhua Global warming Northeast Arctic cod Institute for Marine Research: Brage IMR Arctic Marine Ecology Progress Series 404 173 183 |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
cod torsk fecundity fertilitet spawning gyting VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 |
spellingShingle |
cod torsk fecundity fertilitet spawning gyting VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 Skjæraasen, Jon Egil Nash, Richard D.M. Kennedy, James Thorsen, Anders Nilsen, Trygve Kjesbu, Olav Sigurd Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
topic_facet |
cod torsk fecundity fertilitet spawning gyting VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 |
description |
Marine ecosystems are changing; global warming-induced increases in water temperatures and fishing have caused truncated age structures and small sizes at maturity in many stocks. This may affect both populations’ total reproductive output and the link between population demography and recruitment, yet detailed information on fecundity regulation is generally lacking for marine fishes. We therefore examined associations between liver energy, oocyte stage, leading cohort oocyte size (LC20), atresia and fecundity for the Northeast Arctic cod (NEAC) Gadus morhua L. from 2006 to 2008 in a comprehensive field and laboratory study. The relationship between the relative liver size (hepatosomatic index, HSI) and specific liver energy content was best described by an asymptotic curve, increasing rapidly at first, then levelling of at HSI > 6%. LC20 increased towards the spawning season, but was also positively associated with total length. At present there is thus a tendency towards larger NEAC females spawning earlier. The incidence of atresia was highest during the advanced yolk granule stage. Only 1% of females that reached an LC20 > 300 µm absorbed all oocytes and thereby aborted spawning. Potential fecundity showed a parabolic relationship with LC20, peaking around 614 µm, i.e. approximately on February 1st, and was positively associated with weight, liver energy and, presently, age. In summary, NEAC females that start vitellogenesis will likely spawn. Atresia and fecundity down-regulation appears only to become pronounced close to spawning. Finally, the size-dependent spawning time, which appears to have emerged in the stock recently, may alter the link between population demography and recruitment. 2015-04-08 |
format |
Article in Journal/Newspaper |
author |
Skjæraasen, Jon Egil Nash, Richard D.M. Kennedy, James Thorsen, Anders Nilsen, Trygve Kjesbu, Olav Sigurd |
author_facet |
Skjæraasen, Jon Egil Nash, Richard D.M. Kennedy, James Thorsen, Anders Nilsen, Trygve Kjesbu, Olav Sigurd |
author_sort |
Skjæraasen, Jon Egil |
title |
Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
title_short |
Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
title_full |
Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
title_fullStr |
Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
title_full_unstemmed |
Liver energy, atresia and oocyte stage influence fecundity regulation in Northeast Arctic cod |
title_sort |
liver energy, atresia and oocyte stage influence fecundity regulation in northeast arctic cod |
publisher |
Inter-Research |
publishDate |
2010 |
url |
http://hdl.handle.net/11250/108792 https://doi.org/10.3354/meps08486 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic cod Arctic Gadus morhua Global warming Northeast Arctic cod |
genre_facet |
Arctic cod Arctic Gadus morhua Global warming Northeast Arctic cod |
op_source |
173-183 404 Marine Ecology Progress Series |
op_relation |
urn:issn:0171-8630 urn:issn:1616-1599 http://hdl.handle.net/11250/108792 http://dx.doi.org/10.3354/meps08486 |
op_doi |
https://doi.org/10.3354/meps08486 |
container_title |
Marine Ecology Progress Series |
container_volume |
404 |
container_start_page |
173 |
op_container_end_page |
183 |
_version_ |
1766304265774563328 |