美国4个凡纳滨对虾(Litopenaeus vannamei)种群形态差异与判别分析

MORPHOLOGICAL DIFFERENCES OF FOUR IMPORTED LITOPENAEUS VANNAMEI GROUPS FROM THE UNITED STATES

采用3种多元分析方法,对来源于美国的4个凡纳滨对虾种群的13个形态比例参数进行比较研究。聚类分析结果表明,Kona Bay种群与Molokai种群形态差异很小,而SIS种群、OI种群趋异程度逐渐增加。判别分析结果显示,4种群的13个形态比例参数有着极显著的差异(P>0.01);4个种群雌虾的判别准确率P1为61.76%—97.14%,判别准确率P2为62.03%—96.43%,综合判别率为80.25%;4个种群雄虾的判别准确率P1为75.76%—97.06%,判别准确率P2分别为67.57%—97.06%,综合判别率为80.71%,各种群的判别函数判别准确率均较高;主成分分析,构建的雌体的5个主成分方差贡献率分别为,主成分1:23.594%,主成分2:19.534%,主成分3:15.748%,主成分4:13.653%,主成分5:8.653%。累积贡献率为81.182%。而在构建的雄体的5个主成分中,方差贡献率分别为主成分1:22.095%,主成分2:19.270%,主成分3:15.430%,主成分4:15.245%,主成分5:7.885%。累积贡献率为79.925%。综上所述,Kona Bay种群与Molokai种群应是同一种群,与SIS种群亲缘关系较为接近,SIS种群和OI种群为独立的种群。

Morphological differences among four shrimp groups of Litopenaeus vannamei imported from aquicultural agencies of the United States were studied with 13 morphological parameters using three multivariation analysis methods （cluster analysis, discriminant analysis, and component analysis）. Cluster analysis indicated increasing divergence degrees between SIS and OI groups, and no obvious difference was found between the Kona Bay and the Molokai ones. Discriminant analysis revealed significant differences among groups （P〈0.01） in identification rates ranging 62%--97% or 80.25% in overall, and 68%--97% and 80.71%, for females and males of the groups, respectively. Principal component analysis on the female ones distinguished out five principal components with the contribution of 23.59%, 19.53%, 15.75%, 13.65% and 8.65% respectively, cumulatively to 81.18%; and for the male ones, at 22.10%, 19.27%, 15.43%, 15.25% and 7.89% respectively, and adding up to 79.93%. The results show that the Kona Bay and Molokai groups are in the same population, while OI and SIS groups has become independent ones due to long-term breeding.