Genetic parameters for whole weight and survival rate of the Portuguese oyster, Crassostrea angulata, at different harvest stages after six generations of selection

Abstract

The Portuguese oyster, Crassostrea angulata, is an important aquaculture bivalve species in Asia. This study was carried out to estimate genetic parameters at 240 days, 300 days and 365 days for survival rate and whole weight over six generations of selection. The phenotypic measurements for whole weight and survival rate at 240, 300 and 360 days were collected from the fourth to sixth generations. A linear mixed model was used to estimate heritability and genetic correlations at 240, 300 and 365 days after fertilization for whole weight, and a generalized linear mixed model was used to estimate heritability and genetic correlations at 240, 300 and 365 days for survival rate. Heritability estimates for whole weight were moderate at three studied times, ranging from 0.10 to 0.18. Heritability estimates for survival (h² = 0.11–0.12) whole weight trait and estimates of genetic correlations between survival and whole weight at the three studied ages were moderate to high (0.55–0.77), suggesting that selection to improve one trait at specific, for example, 240 days, 300 days or 365 days, can result in favourable changes in another trait.