STUDIES ON THE CAVITY HELMINTH COMMUNITY OF GYMNOCYPRIS PRZEWALSKII PRZEWALSKII IN QINGHAI LAKE

The cavity of Gymnocypris przewalskii przewalskii is parasitized by three helminths, the plerocereoids of Ligula intestinalis and Diphyllothrium sp. and the third-Stage larvae of Contracaecum rudolphii The abundance of these helminths in diferent size of fish is different. By means of fuzzy cluster and pole ordination, the component community can be divided into tWo groups ie helminths in hosts less than 150 mm in body length and those in hosts more than 150 mm, which is related to the ecological conversion of the host with the growth. The negative assosiation between Ligula intestinalis and Diphyllobothrium sp. and between Ligula intestinalis and Contracaecum rudolphii are obvious.