文摘
DNA barcoding was a molecular diagnostic method that provided rapid and accurate species identification. The 650 bp-length cytochrome c oxidase subunit I (COI) gene of 33 species in Irtysh River China was sequenced and analyzed in this study. The average intra-species, -genus, -family, and -order of Kimura two parameter (K2P) distances were 0.003, 0.060, 0.163 and 0.240, respectively. The genetic distance between genus Barbatula and Cobitis was the largest whereas that between genus Hypophthalmichthys and Aristichthys was the smallest. The neighbour-joining tree constructed by all 44 haplotypes was divided into two major clusters: Cypriniformes fishes and other fishes. A cryptic species of Barbatula barbatula was detected according to 2% genetic threshold.