Preliminary Study On Phyletic Evolution And Distribution Character Of Several Species Of Freshwater Cladocera

38 samples were collected from 30 different sampling positions in 9 provinces which are Yun nan,Jiang su,Zhe jiang,Jiang xi,Hu nan,Shan dong,Si chuan,Xi zang and Hei long jiang during 3 years.The 11 samples are belonged to 4 genus of Cladocera and they are Simocephalus vetulus,Simocephalus sibiricus,Simocephalus serrulatus,Simocephalus heilongjiangensis,Simocephalus himalayensis microdus,Simocephalus beianensis,Sida crystallina,Daphnia carinata,Daphnia obtusa,Daphnia pulex and Ceriodaphnia pulchella.Use the traditional method to describe and record the morphology characteristic of the samples.Due to the few available molecule data and research results of phyletic evolution,the molecular system of them were analysed basing on mitochondrial gene of COI and ribosomal 18SrDNA in this paper.Use Neighbor-joining,maximum likelihood and bayesian inference methods to construct phylogenetic trees.Some species of the Cladocera were used molecular system to analysis and study the relationship of phyletic evolution.Mainly collected species under different geographic and climatic conditions were Simocephalus vetulus,Simocephalus sibiricus,Simocephalus serrulatus and Simocephalus himalayensis microdus which could be collected in the most area of China,especially in Xi zang which altitude is 4830m and the environment is cruel.Thus,they would be studied basing on mitochondrial gene of COI about geographical distribution of Simocephalus.Results show that the species live on geographical environment which the condition of the same or similar,the intraspecific evolutionary relationships are more closely.While,some close relative specises which live in the same cruel during a long time,after a long time adapting and evolution,the relationship of them is close than the same kind of species which live in the other normal environment.