沅江与西江水系大眼华鳊的形态差异

为了探讨沅江和西江水系大眼华鳊（）的形态差异及分化程度，对两个水系5个种群的147个样本进行了测量，共获得9个可量性状和21个框架性状，通过多元分析方法进行了比较。Friedman非参数检验的结果显示，5个种群间的体侧各部分面积存在显著性差异（<0.01）。聚类分析将5个种群分为三支，其中西江两个种群为一支，沅江干流和沅江锦江种群为一支，沅江清水江种群单独为一支。主成分分析共提取出6个主成分，对总方差的累计贡献率为81.93%，贡献率大的性状集中在尾柄部、头部和躯干前部。判别分析筛选出头部和尾柄部的10个性状，分别建立了5个种群的判别函数，判别成功率在92%~100%。3种多元分析方法从框架形态差异上将沅江和西江水系大眼华鳊的种群有效区分开来，为5个种群的形态差异及资源评价提供了基础资料。

Morphological variations of Sinibrama macrops between the Yuanjiang River and Xijiang River basin

is widely distributed in the southwest of the Yangtze River in China. To determine the morphological variations and distribution of five populations in the Yuanjiang River and Xijiang River basin, 147 samples were collected from main streams and tributaries and nine traditional morphological parameters and 21 truss network features were analyzed by three multivariate analysis methods. There were significant differences in the body area of each part of the lateral surface among the five populations, according to Friedman non-parametric tests. Cluster analysis divided the five populations into three groups:one in the main stream and tributary of the Xijiang River, one in the main stream of the Yuanjiang River and the Jinjiang River tributary, and the other in the Qingshuijiang River. Six principal components were extracted by principal component analysis, and the cumulative contribution to the total variance was 81.93%. The characters of higher contribution rate were concentrated in the caudal peduncle, the head, and the anterior part of trunk. Discriminant analysis screened 10 characters of the head and caudal peduncle and established discriminant functions for the five populations, with a range of individual discrimination accuracy between 92% and 100%. Our results suggest that there are significant morphological differences among in the five populations of the Yuanjiang River and the Xijiang River basin, which provide basic data for population identification and resource evaluation for the species.