不同水系松潘裸鲤的形态特征分析

Multivariate Morphometric Analysis of Gymnocypris potanini in Different River Drainages

为了解岷江、大渡河、雅砻江和金沙江水系松潘裸鲤 Gymnocypris potanini 的形态差异,采用常规形态学和多变量形态度量学方法比较分析了采自这4个水系206尾样本的形态特征。结果显示,各水系间松潘裸鲤的第一鳃弓外侧鳃耙数和背鳍、胸鳍、腹鳍及臀鳍鳍条数之间的差异无统计学意义;主成分分析显示,头部(吻端至胸鳍起点/体长、吻端至头背部末端/体长、头长/体长)和尾部特征值(尾鳍背部起点至臀鳍起点/体长、臀鳍起点至尾鳍腹部起点/体长)对形态影响最大;判别分析发现,岷江和雅砻江安宁河种群与其他种群明显分开;聚类分析显示,岷江水系种群聚为一支,金沙江、大渡河、雅砻江水系种群聚为另一支,金沙江水系种群聚在一起,大渡河和雅砻江水系种群未按水系聚在一起,而其聚类关系与种群间的地理距离基本一致;形态差异系数分析显示,可根据臀鳞行列长进行亚种的区分。大渡河和雅砻江水系的松潘裸鲤为硬刺松潘裸鲤亚种。

To investigate the morphological differences of Gymnocypris potanini in different river drainages,206 individuals collected from the Minjiang,Dadu,Yalong and Jinsha rivers were compared and analyzed by morphological measurement and multivariate analysis.There was no significant difference in the number of outer gill rakers and dorsal of the first gill arch,pectoral,ventral and anal fins among the specimens from different river drainages.Principal component analysis showed that the head(snout tip to origin of pectoral fin/body length,snout tip to posterior point of occipital/body length,head length/body length)and tail eigenvalues(dorsal origin of caudal fin to origin of anal fin/body length,origin of anal fin to ventral origin of caudal fin/body length)had the greatest influence on the morphology.Discriminant analysis showed that specimens from the Minjiang River and the Anning River(a tributary of the Yalong River)were distinctly separated from those of other rivers.The populations from the Minjiang River were clustered as one clade,and the other populations from the Jinsha,Dadu and Yalong rivers were clustered into another clade.The populations from the Jinsha River were clustered together,and the ones from the Dadu and Yalong rivers were clustered according to the geographical distance among them.Moreover,the G.potanini subspecies could be discriminated based on the length of anal scale row.The specimens from the Dadu and Yalong river drainages should be identified as G.potanini firmispinatus.