CHARACTERISTICS OF FISH COMMUNITY STRUCTURE IN THE WEIHE RIVER OF SHAANXI SECTION

In order to understand the status of fish resources in Shaanxi Province of the Weihe River, we conducted a survey on fish resources in the Shaanxi section of the Weihe River in four times from 2016 to 2017. A total of 49 species of fish were investigated, which belong to 6 orders, 11 families, 36 genera. The dominant species were Gnathopogon imberbis, Rhynchocypris lagowskii, Abbottina rivularis, Hemiculter leucisculus, Cyprinus carpio and Hypophthalmichthys molitrix. Compared with the results of the survey in 1984, 36 species of fish were reduced with a significant decrease of the variety of species. The similarity index of species composition between two investigations was 0.49, representing a medium dissimilarity. According to Shannon-Wiener index, Pielou’s index, Marglef index, Jaccard’s index and G-F index, the composition of fishes community was obviously changed in the Weihe River of Shaanxi section, and the species diversity decreased by 60%. The analysis of the individual ecology type indicated that the community structure in Weihe Shaanxi section has changed greatly, which are mainly composed of slow flow, omnivorous type, and inhabiting gravel substratum group. The results indicated that the diversity of fish species and the amount of fish resources in the river have decreased significantly, which may explain by the water pollution, decreased water resources and reduced habitat suitability.