Genetic diversity of two color morphs of Northern snakehead (Channa argus) unveiled by the mitochondrial DNA D-loop region

To analyze the genetic background of ‘white’ type Northern snakehead (Channa argus), and provide atheoretical basis for breeding of C. argus, the investigation of genetic diversity and population structure were investigated based on the complete sequences of mitochondrial DNA D-loop region for three cultured ‘white’ type C. argus populations, and four ‘bicolor’ type C. argus populations were used to compare with them; 28 mutation loci and 30 haplotypes were found in the D-loop sequence of all individuals with a total length of 907 bp. The highest haplotype diversity (H(d)) and nucleotide diversity (P(i)) in the ‘white’ type C. argus populations were 0.505 and 0.00057, respectively, which lower than those in the ‘bicolor’ type C. argus populations (H(d) = 0.911, P(i) = 0.00326). Population differentiation values (F(ST)) show that the four ‘bicolor’ type C. argus populations had obvious genetic differentiation (Fst: 0.21902–0.49428. p < 0.01), but not in the three ‘white’ type C. argus populations (Fst: −0.00571 to 0.07261. p > 0.05). The phylogenetic tree and Median Joining (MJ) network showed that the genetic distance among ‘white’ type C. argus populations is very close. Therefore, much attention should be paid to protecting population genetic diversity and avoiding inbreeding in the breeding of ‘white’ type C. argus.