四个尼罗罗非鱼引进种群的形态差异分析

采用聚类分析、主成分分析和判别分析3种多元分析方法,对4个尼罗罗非鱼引进种群的7项比例形态性状参数进行比较研究。聚类分析结果显示,来源地为菲律宾的群体C和群体D的形态最接近,与埃及群体B、泰国群体A趋异程度较大。主成分分析构建了3个主成分,其贡献率主成分1为27.838%,主成分2为18.773%,主成分3为14.917%,累计贡献率为61.529%。采用判别分析的方法建立了4个种群的判别函数,判别准确率P1为50.0%～80.0%,判别准确率P2为61.5%～78.6%,综合判别率达66.7%。3种多元分析结果说明,4个尼罗罗非鱼群体在形态上存在一定程度的差异,且集中表现在全长、体长、头长、体高和尾柄高这5个形态性状上。分析结果显示4个尼罗罗非鱼引进种群在形态上存在一定程度的差异。

Analysis of Morphological Variations among Four Imported Populations of Tilapia nilotica

Three kinds of multivariate analysis methods including cluster analysis,principal component analysis and discriminant analysis were used to study seven morphological proportional traits of four introduced populations of Tilapia nilotica.The results of cluster analysis showed that morphological traits were similar between C and D,but quite different from that of B and A.Principal component analysis distinguished out principal components with the contribution of 27.838 %,18.773 %,14.917 %,respectively,cumulatively to 61.529 %.The discriminant functions of four populations were established.The discriminant accuracy P1 was 50.0 %-80.0 %,and P2 61.5 %-78.6%.The total discriminant accuracy was 66.7%.The results indicated that there were some morphological differences among the four populations of Tilapia nilotica.The indicators of morphological traits were total length,body length,head length,body height and caudal peduncle height.It concluded that there were some differences in four imported populations of Tilapia nilotica.