Morphological variation analysis among five populations of the swimming crab Portunus trituberculatus from China Sea areas

Based on 23 morphological characters of Portunus trituberculatus, three multivariation analysis methods (cluster analysis, principal component analysis and discriminant analysis) were used to comparably reveal the morphological variation among the five geographical populations from China Sea areas (Dalian, Dongying, Lian yungang, Zhoushan and Zhanjiang). The results of cluster analysis and principal component analysis indicated that the morphological characters were similar between Dongying and Lianyungang, but quite different from that of Zhanjiang. In the principal component analysis, three principal components were constructed, and the contributory ratio of the first principal component was 27.39%, the second was15.23%, and the third was 10.27%.The cumulative contributory ratio was 52.89%.The results of discriminant analysis indicated that there were significant differences among the five populations (P0.01). The identification accuracy was 63.64%～94.44%(P1) and 67.74%～ 92.86%(P2), and the total discriminant accuracy was 82.24%.