Morphological difference analysis between migratory population and cultured population of Eriocheir sinensis in the Yangtze River

The morphological difference between migratory population and cultured population of Eriocheir sinensis in the Yangtze River were studied. Thirty- eight morphological parameters were evaluated through the methods of discriminant analysis and variance analysis. Discriminant analysis was separately used for males and females of the two populations. Five parameters were selected to discriminate two groups. Then two discriminant functions for males and females were separately established with these parameters. The fitted probability of male and female E. sinensis was 94% and 92% through these functions. And the discriminant efficiency of the migratory population was higher than the cultured population. The result of variance analysis showed that there were sixteen morphological parameters which were significant ly different between these two populations,and eight parameters which were extremely significant ly different. These eight parameters of coefficient of variation were from 0. 294 to 0. 614. Twelve and eleven morphological parameters of female and male E. sinensis bwtween two population were significant ly different,respectively. The main morphological parameters to discriminate these two groups were the ratios of the frontal teeth space length and the fourth foot knuckle length with shell width.