云南伊洛瓦底江外来种麦穗鱼的形态差异分析

对采自伊洛瓦底江水系和顺、猴桥、龙陵和盈江4个群体共120尾麦穗鱼标本进行11个常规性状和16个框架结构性状的测量,应用多变量形态度量学结合主成分分析和差异系数分析方法比较各群体间的形态差异。结果表明,4个群体间没有显著性差异。其中,主成分PC1、PC2和PC3贡献率分别为26.658%,15.281%和11.395%,累积贡献率为53.334%,在PC1、PC2散点图中,龙陵与猴桥群体部分分出。从27个性状变量中筛选出贡献较大的9个性状(P0.01)与体长的比值进行形态差异系数分析,发现龙陵与猴桥、和顺、盈江群体间差异系数均小于1.28,综上分析,伊洛瓦底江4个麦穗鱼地理群体形态差异不显著,这可能与引入时间较短、引入群体来源于同一种群有关。

Morphological difference of Pseudorasbora parva in Yunnan, Irrawaddy River

In this study, 11 regular characters and 16 frame traits of 120 Pseudorasbora parva among four different geographical populations (Heshun, Houqiao, Longling and Yingjiang) in Irrawaddy River of Yunnan were measured. The data were used for a multivariate morphometric analysis with two different methods, the principal component analysis (PCA) and coefficient variance analysis, to compare the morphological differences among the four geographical populations of P. parva. The results showed that there were no prominent differences among the four populations, except for Houqiao and Longling populations. In PCA analysis, the contribution rates of PC1, PC2 and PC3 were 26.658%, 15.281%, and 11.395%, respectively, which sum up to 53.334%. Furthermore, partial independent samples in Longling were separated from Houqiao in the scatter plots by the PC1 and PC2. In coefficient variance analysis, 9 of 27 character variables (P <0.01) were selected, and the ratios of the 9 traits to the body length were used for variance analysis. It was found that the coefficient differences among Longling, Houqiao, Heshun and Yingjiang populations were less than 1.28, which did not reach subspecies differentiation level. Then, it was speculated that they were geographical populations, not geographical subspecies. The morphological differences were not significant among four populations in Irrawaddy River, suggesting that it may be related to the introduction in a relatively short period, or may origin from the same population in the introduction process.