Intraspecific hybridization as a mitigation strategy of low salinity in marine bivalve noble scallop Chlamys nobilis

Abstract

Noble scallop Chlamys nobilis is one of the most important bivalves in China. C. nobilis aquaculture is mainly carried out in coastal areas that vulnerable to high salinity fluctuations. Hyposaline conditions caused by a large volume of freshwater input from rivers in rainy seasons often leads to mass mortalities of farmed C. nobilis. Interspecific hybridization is a promising approach to improve the growth rate, survival rate and environmental adaptability of bivalves. However, it is not clear whether intraspecific hybridization can be used as a management strategy to mitigate the impact of hyposaline on farmed C. nobilis. Therefore, this study compared the effects of hyposaline on the growth rate, survival rate, total carotenoid content (TCC) and transcriptome data of intraspecific inbred and hybrid C. nobilis. The results of this study revealed that intraspecific hybridization of C. nobilis exhibited significant positive heterosis in growth rate, survival rate and adaptation to hyposaline condition. The stronger adaptation to hyposaline condition is mainly attributed to the induction of genes involved in osmoregulation, cell protection and damaged protein repair. Therefore, intraspecific hybridization is a potential management strategy to mitigate the impact of hyposaline on farmed bivalves (at least for C. nobilis).