Factors Affecting Diversity of Fish Species in Mid- and Upper-streams of Tingjiang River

Correlations among the habitat conditions, diversity of fish species, and human activities were studied using the data collected from 6 locations on the mid- and upper-streams of Tingjiang River in February, May, July, and October from 2012 to 2013. The results showed that the 71 fishes caught belonged to 4 orders, 15 families, and 54 genera. They included the provincial protected species, such as Mastacembelus armatus, the endemic species,Pseudogastromyzon fasciatus, Pseudogastromyzon cheni, Crossostoma stigmata and Crossostoma fascicauda, and the dominant species,Zacco platypus, Pseudobagrus fulvidraco, and Gnathopogon argentatus, along with 12 commonly found species.Based onthe one-way ANOVA, the Shannon-Wiener indices on samples collected from the 6 locations varied significantly.The indices for fish caught at Xinqiao were higher than other localities, with significant seasonal variations. The canonical correspondence analysis (CCA) indicated that the determining factors on the composition and distribution of the fishes in the two sections of the river were water temperature and human activities, while the substrates on the river bed, changes of river channel, stability of bankment, vegetation,as well as the total nitrogen content and permanganate index of the water,also contributed significantly to the diversity and distribution. The human activities along the river not only altered the composition of fish, such as the reduction on the migrotory and endemically specialized species and the increase on the invasive and tolerant species, but also decreased the diversity in the mid- and upper-streams of the Tingjiang River.