叶尔羌高原鳅不同地理群体形态差异分析

Analysis on the Morphological Differences of Triplophysa yarkandensis in Different Geographic Populations

本研究基于多变量形态度量学的方法,对叶尔羌高原鳅(Triplophysa yarkandensis)3个地理群体共计509尾样本的11个形态指标和22个框架指标进行多元统计分析。非参数检验显示,叶尔羌高原鳅3个地理群体的31项比例性状中,4~9/体长(BL)存在显著差异(P<0.05),体高(BD)/BL等26项比例性状存在极显著差异(P<0.01)。主成分分析显示,前3个主成分贡献率分别为25.0%、14.0%和9.3%,累计贡献率为48.3%,差异主要体现在机体头部和躯干前段;聚类分析与主成分分析结果基本一致,叶尔羌河群体与塔里木河群体先汇为一支,后与和田河群体汇为一支,即叶尔羌河群体与塔里木河群体形态差异较小,和田河较另外2个群体形态差异较大。构建判别方程并进行交互验证,判别成功率分别为88.48%、88.89%和87.73%,综合判别率为88.37%,表明由判别分析筛选出9个形态比例性状对叶尔羌高原鳅不同地理群体的判定是可行的。研究表明,塔里木河水系的特殊性造成不同河流生境中叶尔羌高原鳅群体存在形态差异,可通过多元分析对其进行有效区分,但栖息环境的不同可能是引起机体形态学特征差异或适应进化的主要原因。

This study aimed to explore the morphological adaptation and evolution characteristics of Triplophysa yarkandensis, an endemic fish in the Tarim River Basin, and further develop the proliferation and protection of native fish resources in the Tarim River Basin. This study is based on multivariate morphological metrics, and multivariate statistical analysis was conducted on 11 traditional indices and 22framework indices of 509 samples from three geographical T. yarkandensis populations. A non-parametric test showed that, among the 31 proportional traits of the three geographic T. yarkandensis populations,4–9/body length had significant differences(P<0.05), and 26 proportional traits such as body depth/body length had extremely significant differences(P<0.01). Principal component analysis revealed that the contribution rates of the first three principal components were 25.00%, 14.00% and 9.30%, with a cumulative contribution rate of 48.31%. The differences were primarily in the head and in front of the trunk. Cluster analysis and principal component analysis results were essentially identical. The Yarkand River and the Tarim River groups first converged into one branch that then converged into a branch with the Hotan River group. Specifically, the difference between the Yarkand River and Tarim River is small,and the difference between the Hotan River and the other two groups is large. During the verification of the built discriminant equations, the discriminant success rates were 88.48%, 88.89%, 87.73%, and the comprehensive discriminant rate was 88.37%. It is suggested that the nine morphological and proportional characters selected by discriminant analysis are feasible for the preliminary determination of different geographical populations of T. yarkandensis. The results showed that the special characteristics of the Tarim River system resulted in the morphological differences of T. yarkandensis in different river habitats,which could be distinguished effectively by multivariate analysis. However, the differences in habitat environment might be the predominant reason for the morphological differences or adaptation evolution of the fish.