Morphological Variation and Discriminant Analysis in Four Geographical Populations of Loach Barbatula nuda

In the present paper, 14 morphometrical characters were measured in 137 samples of 4 geographic populations of loach Barbatula nuda collected from Tumen River, Songhua River, Yalu River and Heilongjiang River, and discrimination was conducted by one-way analysis of variance, cluster analysis, principle component analysis and discriminating analysis to evaluate the morphological variations among the 4 populations. The one-way analysis of variance revealed that the head height/body length was found significant difference among the 4 populations(P0.05),and that the head length/body length, peduncle length /body length, dorsal snout distance/body length, and dorsal caudal fin distance/body length were very significant differences(P0.01).The clustering analysis and principal component analysis showed the identical results, the minimal difference between Heilongjiang River population and Yalu River population, followed by the Tumen River population and Songhua River population. However, there was great difference between Heilongjiang River populations and Tumen River population, and between Songhua River population and Yalu River population.The discriminating functions were established in the 4 populations with the average discriminant accuracy of 87%. The findings indicate that there were significant differences in morphology among the 4 geographic populations of Barbatula nuda which can be discriminated by differences in morphometrical characters