Comparison of growth and survival among the hybrid offspring of three different shell color families of Pacific oyster(Crassostrea gigas)

A 3×3 diallel crosses of three different shell color families of Pacific oyster(Crassostrea gigas)(white/W, black/B, purple/P)were conducted.Three parental groups and six reciprocal hybrid crosses were established.The growth, survival rate and heterosis of hybrid crosses at larval and grow-out stages were compared among all experimental groups.The results showed that at the larval stage, hybrid cross PB presented significant growth superiority than other experimental groups.The larval survival rates of all the hybrid crosses were higher than that of parental crosses.All the hybrid crosses showed obvious larval survival heterosis.At the grow-out stage, the shell height of parental group PP was significantly greater than that of WW and BB.The grow of hybrid PB was the fastest among the six hybrid crosses, followed by hybrid BP, then hybrid WP and PW were the slowest.The survival rates were not different significantly among all the hybrid crosses and parental crosses during the grow-out stage.The heterosis of shell height, shell length, total weight and survival rate of hybrid cross BP and its reciprocal cross PB were between 3.71%-15.27%, -2.00%-13.10%, 11.23%-41.56% and -2.77%-9.83%, respectively.The other four hybrid groups had no heterosis during the grow-out stage.