Preliminary Study On The Morphological And Genetical Characters Among Five Populations Of Exopalaemon Modestus Heller

Multivariate morphometrics methods , DNA sequence analysis and ISSR-PCR were adopted to make researches on a species of fresh water shrimp (Exopalaemon modestus) sampled from Tai Hu Lake, Dian Chi Lake, Xing Kai Hu Lake, Chao Hu Lake and Hu Lun Hu Lake in China in order to reveal the variation between and within five populations as well as each population character, so as to provide academic support for the protection of excellent population resource.1. The morphological discrimination of five populationsMorphological data of white shrimp (Exopalaemon modestus Heller) collected from five fresh water lakes in China were analyzed. Ten morphometric traits were measured from over 300 shrimps and the level of morphological similarity among sites was calculated using multivariate analysis techniques. Eight from the eleven adjusted morphometric traits in females as well as six in males were effective to discriminate differences among five populations. Discriminant analysis revealed that over 90.8% females and 87.8% males of individuals could be classified to their original sites. The results of cluster analysis and principal component analysis revealed that populations from Tai Hu Lake and Dian Chi Lake were most similar and formed a common cluster when the other three populations from Xing Kai Hu Lake, Hu Lun Hu Lake and Chao Hu Lake formed another branch, which meant that the patterns of morphological variability in this species could be determined by the local environmental conditions, more research work must be done to identify the source of inter-population variability in the morphology of white shrimp.2. The polymorphism of mitochondrial COI sequences of five populationsPCR was conducted using universal primers for invertebrates to amplify mitochondrial COI fragments of 25 randomly selected samples from five populations, followed by bi-direction sequencing and polymorphic analysis. The total percentage of A+T was higher than that of G+C, which was in agreement with the conclusion of many researchers on the analysis of mitochondrial gene sequences. Tai Hu Lake population had most variable locus (13) in total 628bp mitochondrial COI fragment when the number in Xing Kai Hu Lake population, Chao Hu Lake population and Hu...