Strong phenotypic and genetic correlation between size and first maturity in Atlantic cod Gadus morhua L. reared in commercial conditions |
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| Authors: | Theódór Kristjánsson Thorvaldur Arnason |
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| Affiliation: | 1. Stofnfiskur, Hafnarfj?reur, Iceland;2. Agricultural University of Iceland, Borgarnes, Iceland |
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| Abstract: | Three‐year classes of Atlantic cod Gadus morhua were studied throughout their rearing in the eastern coast of Iceland from 2004 to 2011. The growth and status of maturity were recorded during the rearing. For one of the year classes, genetic parameters for body weight and maturity status were estimated from 757 individuals, which were the offspring of 40 dams and 20 sires. The estimate for heritability of body weight was h2 = 0.34 at the average weight of 630 g, and heritability for proportion of maturity was h2 = 0.17 given the same weight. The relationship between body weight and the proportion of mature individuals at first winter revealed a strong genetic correlation of rG = 0.90. The phenotypic relationship between body weight and proportion of maturity was estimated with a Bayesian logistic regression as P(yi = 1(mature)) = Φ(β0 + β1weight + β2sex). The best fit yielded β0 = ?2.9320 with a 95% interval between ?3.2807 and ?2.5394, β1weight = 0.0041 with a 95% interval ranging from 0.0035 to 0.0046 and β1sex = ?0.0201 with a 95% interval from ?0.2003 to 0.1445. The gender had no notable effect. This strong phenotypic and genetic correlation in body weight and maturation suggests that an increased growth rate will consequently lead to a higher proportion of mature individuals in the population. As a consequence, genetic manipulations to simultaneously increase growth and delay maturation may present a challenge. |
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| Keywords: |
Gadus morhua
Atlantic cod heritability maturity genetic correlation |
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