Population genetic differentiation of the black rockfish Sebastes schlegelii revealed by microsatellites

• SSR was used to investigate the genetic structure of Sebastesschlegelii.
• S. schlegelii showed high gene diversity.
• No genetic divergence among populations was found.
• All the populations of S. schlegelii shared one gene pool.

sSebastes schlegelii is one of the fishes that aggregate around drifting seaweed during their early development. To examine the population genetic structure of S. schlegelii, eight microsatellite DNA loci were used to interpret their life history characteristics and larval dispersal strategy. Two hundred and ten individuals from nine sites across the entire range of S. schlegelii in China and Japan were analyzed. The results indicated that the polymorphism information content, observed heterozygosity, and gene diversity of S. schlegelii were high. The results of analysis of molecular variance, pairwise FST values, and exact-P tests showed no genetic divergence among the different geographical populations and indicted the existence of high gene flow. There was no IBD pattern among populations. The results of the STRUCTURE analysis showed all the populations of S. schlegelii shared one gene pool. We concluded that larval dispersal with drifting seaweed and the environmental factors of the currents might play important roles in shaping the contemporary phylogeographical pattern and genetic homogeneity of S. schlegelii. The results of the microsatellite analysis were in accordance with the results revealed by mitochondrial DNA sequences and amplified fragment length polymorphism markers.