Application of DNA barcoding based on CO I gene in phylogenetic classification of Sciaenidae

To study the applicability of DNA barcode technology to identify fish of Sciaenidae,CO I sequences of 7 species of Sciaenidae were amplified and homologous sequences were obtained from GenBank.Ultimately,CO I sequences of 65 Sciaenidae individuals which belonged to 14 genera,23 species were analyzed in this study.Results showed that the A+T content of Sciaenidae CO I sequences were higher than G+C content,and the G+C content of the first codon site was significantly higher than 2nd and 3nd codon site.Intraspecial genetic distance was 0~0.014(average 0.004),interspecial genetic distance was 0.050~0.368(average 0.202),and average interspecial genetic distance was 50.5 times of the intraspecial genetic distance.In the phylogenetic tree,individuals of the same species were grouped into separate branches.Larimichthys and Collichthys formed monophyletic groups separately,while Argyrosomus,Nibea and Johnius didn't.The results indicated that the mitochondrial CO I gene could be used for the effective identification and phylogenetic analysis of Sciaenidae.