ABSTRACT. Distributed along the coastal waters of Korea and China, Octopus minor is found in various habitats, including the mud flats in the southern and western coasts of the Korean Peninsula and the rocky areas around Jeju Island; however, the genetic relationships among the different populations are unknown and have not been studied. We compared 630-nucleotide sequences of the CO1 gene from O. minor specimens collected from five regions around the Korean Peninsula and three regions from eastern China in order to determine population structure and genetic relationships. Based on the sequences at 12 polymorphic sites in this region, 11 haplotypes were identified from 85 specimens. Individuals from Jeju Island had unique haplotypes, including two haplotypes not found in the other populations. Nucleotide and haplotype diversity for all populations ranged from 0.03-0.37 and 0.20-0.64, respectively. Pairwise F ST values indicated significant genetic differences in populations from Korea and China. An UPGMA dendrogram showed separation of the eight populations into three clusters; one included only the Jeju population, another included the rest of the Korean populations and some from Dalian, China; a third cluster consisted of two other populations from China. We conclude that there are discrete genetic differences in O. minor from the different habitats, suggesting that the populations should be considered as management units in the ongoing recovery program.

ABSTRACT. The kelp or longtooth grouper (Epinephelus bruneus), which inhabits Eastern Asia, is the most economically important of 11 grouper species that inhabit the Southern Sea near Jeju Island in Korea. This species is listed as vulnerable by the International Union for the Conservation of Nature and Natural Resources because of a rapid decrease in its resources. We developed microsatellite markers for E. bruneus using the pyrosequencing technique for applications in resource management and aquaculture. In addition, we tested the cross-species transferability of the microsatellite markers in four species belonging to the Epinephelus genus. Among 66,452 simple sequence repeats, 64 loci containing more than eight CA or TG repeats were randomly selected for primer synthesis; 45 primer sets (75.0%) produced polymerase chain reaction (PCR) products of 100- 300 bp and were selected as candidates. After primary testing with four E. bruneus fish, 28 polymorphic loci were selected as the final microsatellite markers, and 23 sets showing clear amplification of polymorphic loci were used to analyze 71 fish. These loci have allele numbers ranging from 2 to 23. Null alleles were detected at three loci, and three loci showed an excess of homozygotes in the Hardy-Weinberg equilibrium test. Of the three species used for cross-species transfer of these markers, Epinephelus moara showed the highest transferability (92.9%) and polymorphism (67.9%), followed by Epinephelus fuscoguttatus (75.0 and 67.9%, respectively) and Epinephelus septemfasciatus (57.1 and 46.4%, respectively). These results suggested that these microsatellite loci should be valuable tools for population genetic studies of the species Epinephelus.