The effect of stress on reproduction in Atlantic cod |
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Authors: | M J Morgan ‡ C E Wilson † L W Crim † |
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Institution: | Science Branch, Department of Fisheries and Oceans, P.O. Box 5667, St John's, Newfoundland, A1C 5X1 Canada;Ocean Sciences Centre, Memorial University of Newfoundland, St John's, Newfoundland, A1C 5S7 Canada |
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Abstract: | This study imposed stress upon spawning cod Gadus morhua in the laboratory to evaluate the potential effects of trawl avoidance on their reproductive physiology and spawning behaviour. Plasma cortisol levels of stressed fish were significantly higher than controls. Stressed cod initiated fewer courtships and often performed an altered courtship sequence. Both control and stressed fish spawned and there was little difference in the production of eggs, fertilization rate, hatching success or time to starvation of larvae. However, stressed fish produced abnormal larvae more frequently. Cod exposed to a chronic stressor are able to spawn successfully, but there appears to be a negative impact of this stress on their reproductive output, particularly through the production of abnormal larvae. |
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Keywords: | stress courtship egg quality larval quality |
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