Effect of siblings on growth of juvenile coho salmon (Oncorhynchus kisutch)

Abstract

Five male coho salmon (Oncorhynchus kisutch) were mated to 10 females in a nested mating design, and juveniles from these 10 families were marked and reared for 30 weeks. Juveniles from each family were reared in one of three environments: with full-sibs, with paternal half-sibs, and with all members of the other nine families in a communal tank. Juveniles reared with full-sibs showed the greatest within-family variation in body weight and those reared with nine other families in the communal environment showed the least, so that the phenotypic expression of body weight was influenced by the degree of kinship of individuals in the environment. Significant genotype – social environment interactions were observed in juvenile body weight, with the average weight of a family member dependent upon the other genotypes present in the rearing environment.