Abstract:

Aim: The Sichuan Nuoshuihe Precious Aquatic Animal National Nature Reserve is located in upper reach of the Qujiang River, a tributary of the Jialing River, and is comprised of the Datong River and its tributary Xiaotong River. In order to understand the status of fish resources in the reserve, a comprehensive investigation was carried out across the rivers’ watersheds.
Methods: The investigation was implemented in November 2015; March, May, and September 2016; and January 2017 at a total of 30 sampling sites. It took one to three days at each sampling site for each survey to collect fish samples by using gill nets, ground cages, and small backpack electric fishing machines (approved by the Fishery Administrative Department).
Results: A total of 57 fish species belonging to 4 orders, 13 families and 45 genera were recorded in the reserve. Forty-seven species were collected during the survey, and the other 10 species were confirmed through fishermen. Among them, Procypris rabaudi is the second-class state key protected wildlife in China. Twelve of the fish species are endemic to the upper Yangtze River and three species are listed as vulnerable in Red List of China’s Vertebrates. The fish in the reserve are dominated by small-bodied species, of which Zacco platypus, Gnarhopogon herzensteini and Pseudobagrus truncatus are the most dominant species. It was shown that the diversity of the fish community in the reserve is rich, with Shannon-Wiener diversity index, Margalef richness index, Simpson dominance index and Pielou evenness index of 2.900, 5.198, 0.931 and 0.753, respectively. The Jaccard’s similarity coefficients showed high similarity of species composition between the Datong and Xiaotong rivers.
Conclusions: The similarity of fish communities between different reaches of the same river (the Datong River or Xiaotong River) showed negative correlation to their distance, and the reaches of the Datong River and Xiaotong River with similar elevation range showed high similarity of fish community. The decline of fish resources in the reserve was mainly caused by anthropogenic activities such as overfishing, habitats destruction and water pollution.

Key words: Sichuan Nuoshuihe Precious Aquatic Animal National Nature Reserve, fish resources, dominant species, species diversity, community similarity