DNA barcoding for fish species identification and diversity assessment in the Mae Tam reservoir, Thailand

The purposes of this research were to identify fish species using DNA barcodes or partial sequences of cytochrome b (Cytb) and to assess the diversity of fish in the Mae Tam reservoir, Phayao province, Thailand. Fish samples were collected 3 times, during the winter, summer, andrainy seasons, from 2 sampling sites using gillnets with 3 mesh sizes (30, 50, and 70 mm). A total of 34 representative samples were classified into 12 species, 7 families and 6 orders bymorphological- and DNA barcoding-based identifications. However, one cichlid species, Cichlasoma trimaculatum, could only be identified using DNA barcoding. Family Cyprinidae had the greatest diversity, 50.00%. The diversity, richness and evenness indices ranged from 0.43-0.65, 0.64-1.46, and 0.27-0.40, respectively, indicating that fish diversity at both sampling sites was relatively low. A comparison of the catch per unit effort (CPUE) with 3 different mesh sizes found that the 50 mm mesh size was the best (474.80 ± 171.56 g/100 m2/night), followed by the 70 mm (417.41 ± 176.24 g/100 m2/night) and 30 mm mesh sizes (327.88 ± 115.60 g/100 m2/night). These results indicate that DNA barcoding is a powerful tool for species identification. Our data can be used for planning the sustainable management of fisheries resources in the Mae Tam reservoir.