The effect of interstrain hybridization on the production performance in the Pacific oyster Crassostrea gigas

Abstract

Intra-specific hybridization was carried out using three strains (C, J and K) of Crassostrea gigas, which were successively mass selected for two generation from three culture stocks collected from China, Japan and South Korea. Detailed comparison on larval growth development and the growth and survival of the spats and adult were carried out among six hybrids and three parental groups. By way of the serial growth traits measurements (shell height, shell length and the whole body weight), the obtained results reveal that six hybrid crosses were inferior to those of parental crosses to different extend at larval stage, while at spat and adult stages some differences were observe. It was noted that the cross CJ (C♀×J♂) outperformed all the other groups in all growth traits (P<0.05) and at harvest, the shell height, shell length and the whole body weight reached to 75.64(±11.68) mm, 46.35(±9.06) mm, 42.11(±10.53) g, respectively. For spats and adults survival rate, the hybrid crosses CJ and CK (C♀×K♂) were larger than three parental crosses (P<0.05) and that of the reciprocal hybrids crosses CK and KC (K♀×C♂) were significantly (P<0.05) larger than the parental crosses CC (C♀×C♂) and KK (K♀×K♂), which were 65.14±5.50% and 77.33±4.16% (spats), 57.59±4.17% and 71.33±4.16% (adults), respectively. Considering the growth and survival conditions, the results concluded that the crosses CJ, CK and KC in this work were deemed to be the better hybridization combinations for genetic improvement, which could have significant implications for the development of oyster aquaculture. Statement of relevanceThree different culture stains of Crassostrea gigas, which were successively selected for two generations, were evaluated for growth and fitness traits, as well as for their reciprocal crosses, to determine if heterosis exists in growth and survival traits at different stages by rearing them under the same conditions. Our results could have significant implications for the development of oyster aquaculture.