Abstract:

To study the morphological differences between Cipangopaludina chinensis Gray and Cipangopalndina cathayensis, 11 characteristic indexes and 23 trait parameters of 185 specimens were analyzed by one-way analysis of variance, principal component analysis, cluster analysis and discriminant analysis. The results of one-way ANOVA showed that the morphological differences between the two species were significant (P< 0.05). Six principal components were constructed by principal component analysis, and their contribution rates were 37.278%, 17.038%, 11.606%, 11.606%, 9.912%, 7.471% and 6.228%, respectively. The cumulative contribution rate of them was 89.533%. In the scatter plot constructed by principal component 1 and principal component 2, the specimens’ differences between the two species were obvious, which mainly focused on the characteristics of the spiral part and the contour of the body, and were consistent with the results of cluster analysis. Two characteristic of body height / body width and helix width/ body width were selected from 23 morphological proportion parameters by stepwise discriminant method. Two discriminant functions were established: Y = -609.11+1067.27X₁ + 528.48X₂, Z = -673+1084.59X₁+579.95X₂. By testing the data back to the function, the comprehensive discriminant rate could reach 95.15%, indicating that the two species can be effectively distinguished. These differences and discriminant functions can provide foundation data for the genetic breeding and identification of Cipangopaludina chinensis and Cipangopalndina cathayensis.

Key words: Cipangopaludina chinensis, Cipangopalndina cathayensis, morphological comparison, multivariate analysis