Otolith growth and zone formation during first maturity and spawning of Atlantic cod (Gadus morhua)
Specific impacts of somatic growth, sexual maturation and spawning events on otolith zone formation in Atlantic cod (Gadus morhua) were assessed in a 33-mo tank experiment, using Barents Sea cod and Norwegian coastal cod. High and low feeding ration combinations were used to mimic environmental stre...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
NRC Research Press (a division of Canadian Science Publishing)
2019
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1807/97168 http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2019-0033 |
| Summary: | Specific impacts of somatic growth, sexual maturation and spawning events on otolith zone formation in Atlantic cod (Gadus morhua) were assessed in a 33-mo tank experiment, using Barents Sea cod and Norwegian coastal cod. High and low feeding ration combinations were used to mimic environmental stressors in the field. For both stocks apparent macrostructural “spawning zones” in otoliths are registered in statutory stock monitoring programs to estimate age at maturity, thus adding key information to stock biomass assessments. We found that substantial energy investments in reproduction caused reductions in otolith growth and altered proportional width between translucent and opaque zones. These effects, however, were only significant among individuals with high reproductive investments, while otoliths from individuals with low investments did not differ from the ones for immatures. Reproduction may thus not necessarily induce spawning zones, and alternatively, “spawning zones” may not necessarily reflect reproduction. Altogether, this suggests that the individual energy level, as a premise for metabolic activity, plays a key role in the formation of such zones, and thus is related to environmental conditions. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author. |
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