Levels and patterns of genetic variation in Japanese whiting ( <i>Sillago japonica</i> ) based on mitochondrial DNA control region

Abstract

Japanese whiting (Sillago japonica) is a commercially important demersal fish distributed along the coasts of East Asia and becomes recently an aquaculture species. Despite its commercial importance, the levels and patterns of population genetic variation remain poorly understood. In this study, 346 specimens were collected from 14 localities along the coastal waters of China, Korea and Japan and their genetic variation was analyzed with mtDNA control region (D-loop) sequences. A total of 131 polymorphic sites were detected which determined 294 haplotypes. A pattern with high levels of haplotype diversity (h = 0.999 ± 0.001) and nucleotide diversity (л = 0.030 ± 0.015) was detected in the examined range. Analyses of analysis of molecular variance (AMOVA) and F_st showed that no significant genetic differentiation existed among China, Korea and Japan populations, excepting for the populations between Ise Bay (IBP) sample and the other ones. Minimum spanning tree (MST), neutrality tests, mismatch distribution and Bayesian skyline analyses indicated that the species along coastline of China, Korea and Japan have experienced population expansions originated in its most recent history at about 106-423 kya during the late Pleistocene glaciations and deglaciations periods.