Population genetic structure of the tongue sole (Cynoglossus semilaevis) in Korea based on multiplex PCR assays with 12 polymorphic microsatellite markers

The tongue sole, Cynoglossus semilaevis, is an important fishery resource in Korea. About 100 tongue sole sampled from three major habitats along the western coast of Korea were assessed using multiplex assays with 12 highly polymorphic microsatellite loci to explore the population genetic structure of the species; 151 alleles and similar high levels of gene diversity (mean number of alleles (N_A) = 10.42, mean expected heterozygosity (He) = 0.78) were detected. Three populations showed significant Hardy–Weinberg equilibrium deviations at four loci. Although a significant difference in the number of unique alleles was observed among populations, genetic population subdivision was low by F-statistics (overall F _ST = 0.007, p < 0.05). However, this substructure was not supported by analysis of molecular variance or analyses of isolation by distance. The results suggest a lack of genetic structure among the tongue sole populations in Korean waters and that the populations should be managed as a single unit. The lack of genetic differentiation among samples may be due to high levels of larval dispersal in ocean currents. Alternatively, the populations may have diverged too recently for significant genetic differentiation to have become evident. Given the intensity of tongue sole aquaculture activity in China, which adjoins the western coast of Korea, the possibility that aquaculture may have partially contributed to the population genetic characteristics detected cannot be excluded. This study provides the basic information on nature population structure of C. semilaevis that may help to preserve and manage tongue soles in Korea.