Fish resource survey on Cihaxia to Jishixia stretches in the upper reaches of Yellow River(2005-2010)

We carried out a six-year survey on fish resource of Cihaxia to Jishixia stretches in the upper reaches of Yellow River from 2005 to 2010.Totally,39 fish species were found and were belong to 6 orders,9 families and 29 genera.Among these,only 16 species were native and more than 20 exotic species widely distributed in the upper reaches of Yellow River.7 species including 1 native and 6 exotic species are new recorded for this stretch.Based on composition of catches,we evaluated the species diversity using Margalef richness index,Shannon-Wiener index,Simpson dominance index and Pielou evenness index,respectively.The results showed that the stretches from Cihaxia to Jishixia of the upper reaches of Yellow River holds low fish diversity,which can be attributed to the high altitude and deterioration of the environment.There are significant difference in catches composition among sample sites.We also investigated that fish feeding,spawning ground,and reproductive period and habitat characters of the dominant species.