DNA barcoding for identification of fishes in Xiangjiaba reservoir area in the downstream section of the Jinsha river

摘要

The downstream section of the Jinsha River is a global biodiversity hotspot for fishes. However, cascade hydropower development has altered the original habitat and has had a huge impact on the area's fish diversity. To assess the power of DNA barcoding and construct a DNA barcode library for Xiangjiaba reservoir area, 333 fish mitochondrial DNA barcodes (672 bp) employing a fragment of the mitochondrial cytochrome c oxidase subunit I gene (COI) were obtained for 57 species from the Xiangjiaba reservoir area in this study. The intra-specific genetic distances were below 2%, ranging from 0 to 1.69% (mean 0.19%). The interspecific genetic distances within genera ranged from 0.45 to 11.14% (mean 2.98%). The Bayesian inference (BI) tree and neighbor-joining (NJ) tree inferred that all species were unambiguously separated, with strong support values at the terminal branches except the node of Hemibarbus maculatus shared with its adjacent clade. The DNA barcoding gaps could accomplish fish species discrimination. These results revealed that DNA barcoding was an effective tool for the identification of fish species, and that it was possible to construct a robust DNA barcode reference library for fish species in the Xiangjiaba reservoir area. The results will contribute to future efforts in monitoring, conservation, and management of fish resources.