Analysis of Morphological Variation in Six Common Carp (Cyprinus carpio) Populations

Data of the morphometric characteristics were observed by one-way ANOVA analysis, principal component analysis (PCA) and cluster analysis on 6 common carp populations including Huanghe carp (Cyprinus carpio haematopterus Teminck et Schlegel), purse red carp (C. carpio var. wuyuanensis), high-dorsal purse red carp (C. carpio var. wuyuanensis), Xingguo red carp (C. carpio var. xingguonensis), Jian carp (C. carpio var. jian) and Heilongjiang wild carp (C. carpio haematopterus). The one-way ANOVA analysis showed that there were obvious differences in some morphometric characteristics except the ratio of Length of eye posterior edge to operculum to Head length among the six common carp populations. The PCA constructed 3 principal components with the contribution of 35.316%, 23.221% and 10.146% respectively, which expressed the 68.683% of the cumulative variance. The 6 common carp populations could be divided into 2 clusters. The populations of purse red carp and high-dorsal purse red carp were obviously differentiated from the other populations. The result of Cluster Analysis was in accordance with the PCA results. The coefficients of difference with the value more than 1.28 observed in several populations concerning morphometric characteristics of the ratio of body depth to standard length, head length to standard length, body width to standard length and caudal peduncle depth to caudal peduncle length indicated subspecific difference in these 4 kinds of morphometric characteristics. The results showed that there were distinct differences among the 6 populations, which were related to the morphological characteristics of body shape and head shape.