Molecular evidence of two colour morphs of northern snakehead () based on mitochondrial 12S rRNA.

As an unclassified species, white-type has existed for many years. In the present study, the relationships and genetic diversity in two colour morphs of northern snakehead were determined by the analysis of mitochondrial 12S rRNA gene, as well as other Channa species. The results of sequence analysis showed that the average genetic distance was 0.046 with the interspecies genetic distance ranging from 0.000 to 0.130; and the average interspecies genetic distance was estimated as 0.003 (range: 0.000-0.006). For the two colour morphs of , the mean pair-wise genetic distance between them was also estimated as 0.003. Moreover, molecular phylogenetic tree was constructed using MEGA6.0, which showed that all the haploids gathered together as a branch and crossed each other. These results indicated that the white and biocolour-type belonged to the same species, rather than subspecies at the molecular level, and the white-type should be regard as an albino of biocolour type.