Fish Diversity in Chongqing Section of the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River in 2021

In March 2021, the fish diversity in Chongqing section of the National Nature Reserve for rare and endemic fish in the upper reaches of the Yangtze River was detected. The diversity composition of fish was detected by environmental DNA macro bar code standardized analysis processes such as water sample collection, Edna capture and extraction, PCR amplification and sequencing and database comparative analysis. The results showed that a total of 74 species of fish (excluding 3 genera not identified at the species level) were detected at 6 sampling points in Chongqing section of the reserve, belonging to 6 orders, 16 families and 52 genera, including 2 species of national protected fish, 10 species of endemic fish in the upper reaches of the Yangtze River, 1 species of key protected fish in Chongqing and 8 species of alien species. Cyprinus, Carassius, Ctenopharyngodon and tachysurus were detected as dominant species at each sampling point. There is little difference between alpha and beta diversity indexes of fish composition at various points, indicating that the ecological structure of fish in the reserve is relatively balanced and stable.