Heritability estimates for growth-related traits in the Pacific oyster (<i>Crassostrea gigas</i>) using a molecular pedigree

Abstract

Pacific oyster is one of the leading species in world aquaculture, but heritability estimation applying mixed-family approach has not been actively pursued. In this study, heritability for growth-related traits in the Pacific oyster was first estimated by creating a single cohort of 45 families in a full-factorial mating design consisting of nine sires and five dams. A total of 270 offspring were analysed and parentage assignment inferred by six microsatellite markers achieved 100% success. All parents contributed to the spawn and a total of 42 full-sib families were represented. Using an animal model, heritability estimates at 12 months of age were 0.49 ± 0.25 for shell height, 0.36 ± 0.19 for shell length, 0.45 ± 0.23 for shell width and 0.35 ± 0.17 for wet weight. Genetic correlation between shell height and wet weight was quite high (0.79 ± 0.25), suggesting that direct selection of shell height, which is an easily measurable trait, also improves wet weight. The results obtained in this study indicate that growth-related traits could be improved by exploiting additive genetic effects through selective breeding.