Genetic diversity of Northern snakehead (Channa argus) based on complete mitochondrial COI gene sequences

White type Channa argus, which has the common name of the great northern snakehead, has an uncertain classification for many years. In the present study, mitochondrial COI gene has been used to analyze the relationships and genetic diversity of nine kinds of Channa. For the Chnannidae family, the average of the inter-species genetic distance was 0.156 (ranged: 0.000-0.245). And the intra-species genetic distances were ranged from 0.000 to 0.002. For the haplotypes of two-colour morphs of Channa argus, the mean of the pair-wise genetic distances was estimated as 0.0009. This value was within the intra-species genetic distance interval, indicating that two-colour morphs of Channa argus are not subspecies of white type at the molecular level. Moreover, take Lateolabrax maculates and Epinephelus coioides as outgroups, molecular phylogenetic tree showed that all the haploids gather together as a branch and crossing each other. These indicated that the white type Channa argus should be regarded as an albino of bio colour type.