DNA barcodes for the identification of species diversity in fish from Kwan Phayao, Thailand

The study of fish diversity and species identification is an important component of fisheries management. However, identification based on morphological characteristics is difficult and complex for a nonspecialist to perform. DNA barcodes or the partial sequences of the cytochrome c oxidase I (COI) gene were used to identify fish at the species level. The samples were collected from May 2012 to May 2017 in Kwan Phayao, northern Thailand. In the similarity search, a total of 174 samples were identified as belonging to 52 species, 18 families, and 8 orders with 97-100% identities from both GenBank and BOLD databases. Only COI sequences of two fish species (Mystus singaringan and Parambassis siamensis) had not been reported in both databases. Owing to three species of the genus Labiobarbus, including L. lineatus, L. siamensis, and L. leptocheilus, having very similar characteristics and being difficult species to identify, high-resolution melting analysis was used to differentiate them. Only one of the three primer pairs could clearly identify these species. The results indicated that DNA barcodes are an effective approach to identify fish species for diversity studies and could be used to manage the fisheries resource in Kwan Phayao in the future. •DNA barcode use was an efficient approach to identify the fish species in Kwan Phayao, northern Thailand.•The diversity of fish species included 52 species, 18 families, and 8 orders. These numbers are different from those of previous studies.•HRM analysis could clearly discriminate three species of the genus Labiobarbus, including L. lineatus, L. siamensis, and L. leptocheilus, using only one primer pair that covered a polymorphic region.