LAUSR

Identification of the population structure of harvested species is the first step in the management of wild fisheries. Although the marbled rockfish Sebastiscus marmoratus is a commercially important species in Japan, information on the population structure of this species is limited. We analyzed 646 individuals of S. marmoratus from 13 sampling locations in the coastal waters of western Japan using seven microsatellite markers with the aim to examine the genetic population structure and establish baseline data on the genetic diversity and effective population size (Ne) of this species. Our results indicate that western Japan populations are characterized by a large Ne and that genetic diversity is higher than has been previously reported. We performed several population genetics analyses but these failed to provide evidence of appreciable genetic population structure, although low but significant genetic differentiation was found in 2.6% of the population pairs. This study provides baseline information on the genetic diversity and population structure of S. marmoratus in the coastal waters of western Japan.