Mitochondrial DNA variation and population genetic structure in the small yellow croaker at the coast of Yellow Sea and East China Sea

Small yellow croaker is one of the most important fishery species in China. The mass-scale artificial propagation of this fish species was initially developed in 2015 with the aim of facilitating the fish production stock enhancement and aquaculture programs in the future. In the present study, the wild broodfish and its corresponding progeny along with three other wild populations were sampled and subjected to sequence analysis of the mitochondrial cytochrome c oxidase subunit I gene. The genetic diversity and population genetic structure were evaluated with a total sample size of 141 individuals representing the populations of the Yellow Sea (Qingdao and Lvsi populations) and the East China Sea (Xiangshan and Ningde populations). The wild populations were characterized by high haplotype diversity (0.925-0.976) and low nucleotide diversity (0.376%-0.560%). The hierarchical analysis of molecular variance (AMOVA) analysis and the values of pairwise Ф-statistics (ФST) indicated non-significant genetic differentiation among the four wild populations. The hatchery stock XSH exhibited lower indices of genetic diversity compared with the wild populations that could be attributed to the small effective population size. The findings of the present study have valuable insight to the sustainable management and utilization of this resource.