ANALYSIS OF MORPHOLOGICAL VARIATIONS AMONG THREE WILD AND ONE CULTIVATION POPULATIONS OF MARSUPENAEUS JAPONICUS

Morphological differences among four groups of Marsupenaeus japonicus were studied with 13 morphological parameters using three multivariation analysis methods(cluster analysis,discriminant analysis,and component analysis).Cluster analysis showed that clams from the Guangdong Zhanjiang and Hainan Lingao population were rather similar in morphology,whereas the Fujian Xiamen population differed greatly from other populations.Through principal component analysis,six principal components were established,with their contributory rates being 23.084%,17.976%,15.321%,13.84%,12.707%,and 7.770%,respectively,and the cumulative contributory rate being 90.699%.The stepwise discrimination analysis revealed that the four populations differed significantly in morphology(P0.01).Further,the discrimination functions of the four populations were set up,the discrimination accuracy being 100% for both P1 and P2,and the integrative discrimination accuracy being 100%.The overall results indicate that blind seed selection is relevant to the miniaturization of the cultured population,and that there are some morphological differences among the four populations,e.g.characteristics of carapace.