Study on Fish Species Diversity in the Pingzhai Reservoir Based on Environmental DNA Technology

This study elucidated the composition and diversity characteristics of the main fish species in the Pingzhai Reservoir by collecting and analyzing environmental DNA (eDNA) samples from the reservoir and comparing them with data from traditional fishery resource surveys. The results showed that eDNA technology detected 43 fish species spanning 37 genera, 5 orders, and 11 families. Importantly, no significant difference in fish diversity was observed among the surveyed sites, and the potential of eDNA technology in studying fish diversity in the Pingzhai Reservoir was discussed. A total of 29 species distributed across 18 genera, 3 families, and 3 orders were captured using traditional resource surveys. Overall, 21 fish species were detected using both methods, constituting 48.8% of the total fish population. Cypriniformes were the most prominently detected order in both methods. Among all the fish species, the most abundant in the Pingzhai Reservoir were the free-range fish species Hypophthalmichthys molitrix and Hypophthalmichthys nobilis, which have the largest sequence abundance in the eDNA investigation, in addition to the detection of exotic species, such as Micropterus salmoides and Oreochromis niloticus. Compared with traditional investigation methods, eDNA technology offers several advantages, including high sensitivity, minimal ecological impact, superior data accuracy, and low cost, making it suitable for fish diversity research in fishery resources investigations. This study enhances our understanding of fish diversity in the Pingzhai Reservoir and provides crucial basic information to support the ecosystem management and restoration efforts of the reservoir.