FISH FAUNA AND ITS DIFFERENTIATION IN THE UPLAND LAKES OF YUNNAN
LI SHUSEN (Kunming Zoological Institute, Aeademia Sinica, Kunming)
This paper reports the faunistic composition and differentiation of fishes in the upland lakes of Yunnan,and discusses the causes of the drastic differentiation of certain groups.The characteristics of the fish fauna of the lakes are as follows: (1) The fauna is not rich as a whole,consisting of sixty-five species (subspecies) only.The number of fish species of the lakes is related with size of the lakes,large lakes having more fish species than the smaller ones.(2) There are forty-four endemic species,i.e.about 68% of the the total number of species.Endemic genera,such as Sinocyclocheillus Pang and Mesocypris Fang are also found present.(3) The differentiation of taxa is remarkable,especially in the genus Cyprinus.(4) A few piscivorous fishes are found present,of which the lurking type exceeds the chasing type in the number of species.The zoogeographical features of the fish fauna of Yunnan upland lakes are analysed.The fauna is considered to belong to the South-western Kegion of the Indo-China Subrealm.The fish fauna of the western group of lakes exhibits transitional characters of Palaearctie and Oriental Eeaims,but the fauna of the southern and eastern groups of lakes is considered to belong to the South-China Region.The reason why the fish fauna is simple in composition is also discussed in the paper.