日本沼虾4种群的形态差异分析

4种群日本沼虾（Macrobrachium nipponensis）分别取白洪泽湖、太湖、广西3地大然水域和浙江德清人工养殖池塘。经在相似条件下暂养7个月后，运用3种多元分析方法对四者的10项形态比例参数进行比较研究。聚类分析结果表明，养殖种群与洪泽湖种群的形态最接近，而与太湖种群、广四种群的趋异程度逐渐增加。主成分分析结果显示，养殖种群的成体规格小于吲期的3个野生种群，而3个野生种群中又以洪泽湖种群的规格最小。以判别分析建立了4种群的判别函数，判别准确率分别为：76．7％-86．7％（P1）和74．3％～96．0％（P2），综合判别率81．7％。3种多冗分析结果均认为，4种群R本淄虾在形态上已产生一定程度的差异，且集中表现在头胸甲部的性状上，但所有差异均未达到业种水平，须有多项参数综合判别才能辨别；养殖种群的小型化与选种不当密切相关。

Analysis of morphological variations among four populations of Macrobrachium nipponensis

Based on 10 proportional parameters of morphometric characters,three multivariation analysis methods were conducted to investigate the morphological variations among four populations of M.nipponensis which were collected respectively from Hongze Lake,Taihu Lake,Guangxi Province and the artificial culture pond of Deqing,Zhejiang Province and were fed under similar environmental ponds for seven months.The results of cluster analysis showed that the morphometric characters of the cultured population were more similar to that of Hongze Lake population than to those of the populations of Taihu Lake and Guangxi.Principal component analysis revealed that the adults of the cultured population were smaller than those of the three wild populations among which the population of Hongze Lake had the smallest size.Discriminant analysis indicated that there were significant differences among the four populations, that the identification accuracy of the discriminant functions of these populations were 76.7%-86.7%(P_1) and 74.3%-96.0%(P_2),that the total discriminant accuracy was 81.7%.All results supported that blind seed selection was relevant to the miniaturization of the cultured population,and that there were some morphological differences,which focused on the carapace characters,among the four populations,but the morphological variation of them was characterized under-subspecies,so integrative distinction was needed in differentiation.