Abstract

Climatic oscillations during the Pleistocene ice ages in the Northwestern Pacific produced great changes in species’ geographical distribution and abundance, which could be expected to have genetic consequences in marine fishes. In order to estimate the demographic history and genetic structure of Epinephelus akaara in South and East China Sea, 87 individuals were sampled from 7 localities throughout the distribution range of the species. Mitochondrial DNA (mtDNA) variations were analyzed using DNA sequence data from the 5’ end of the control region. Nucleotide diversity was moderate in E. akaara (0.011). The demographic history of E. akaara was examined using neutrality test and mismatch distribution analyses and results indicated late Pleistocene (162,000 ~ 542,000 years ago) population expansion occurred in the species. Molecular variance analysis (AMOVA) and conventional population statistic F_ST revealed statistically significant levels of genetic structuring existed in E. akaara.

Key words: Climatic oscillations, Epinephelus akaara, mtDNA, population expansion, population genetics