Identification of Channa species using the partial cytochrome c oxidase subunit I (COI) gene as a DNA barcoding marker

The snakehead fish of the genus Channa are an important food fish in China. However, the molecular identification and phylogeny of this genus is poorly understood. Here, we present the utility of partial sequences of the COI gene for use in DNA barcoding for the identification of Channa individuals, which includes four species: Channa argus, Channa maculata, Channa asiatica, and Channa striata. A total of 19 haplotypes were identified in this study. The interspecific K2P distances were higher than intraspecific distances. The lowest interspecific distance (0.091) was between C. argus and C. maculata while the highest interspecific distance (0.219) was between C. argus and C. striata. No intraspecific-interspecific distance overlaps were observed, and a distinct barcoding gap was found between intraspecific and interspecific distances in each species. Our results showed that the partial COI gene is an effective DNA barcoding marker for identifying Channa species.