Estimates of heritability based on additive-dominance genetic analysis model in red swamp crayfish, Procambarus clarkii

Heritability has been proven as an effective means for assessing the genetic variation harbored in populations of aquaculture species. In order to make an overall genetic evaluation, heritabilities of twelve traits in red swamp crayfish, Procambarus clarkii (5 months old), including growth, body dimension and processing traits, were estimated in this study. The estimation was based on the additive-dominance genetic analysis model using the incomplete diallel cross between three geographic populations of the species under two rearing environments. Results indicated that all heritabilities for mature females (n = 1312) and males (n = 1109) were low to medium in magnitude (P < .05), ranging between 0.06 (±0.02) and 0.32 (±0.05). All traits were controlled by additive effect, dominance effect, additive × environment, dominance × environment interactions and other environmental effects to varying degrees, depending on traits in question. Body length, abdominal length, total weight and processing traits were primarily controlled by additive effect, dominance effect, A × E and D × E interactions, while other body size traits were mainly controlled by dominance effect and D × E interaction. With the effects of non-additive genetic and environmental sources removed, estimates of heritability obtained were more accurate. It is anticipated that better genetic gain for improvement of economically important traits, especially processing traits, would be achieved via mass selection in P. clarkii.