Identification of Northeastern Pacific Rockfish Using Multilocus Nuclear DNA Genotypes

Abstract

Molecular genetic analysis has long been used to identify species or populations that otherwise may be difficult to distinguish. More than 100 species of rockfish (genus Sebastes) occur worldwide, and more than 50 species may be found in relatively small regions, such as the Monterey Bay or Channel Islands in central and southern California. Many species are morphologically similar, particularly during the early larval stages, and identification to the species level is time-consuming and problematic for some groups. We describe a simple genetic method for the rapid identification of rockfish species by means of multilocus nuclear genotypes from a panel of six microsatellite loci. Application to a set of known rockfish tissue samples, including fish collected in different parts of their geographic ranges and species not represented in the reference data set, resulted in high assignment accuracy for the represented species and exclusion of the nonrepresented species. Members of the subgenus Pteropodus, for which assignment is difficult with the standard six-locus panel, are accurately identified to the species level with an additional five loci selected for that purpose. Together, these panels correctly assigned 97.4% of the tested individuals from a group of more than 30 species commonly found in central California.