凡纳滨对虾各月龄性状的主成分与判别分析

Principal component and discriminant analyses of traits of Litopenaeus vannamei at different ages

为了研究凡纳滨对虾各性状增长规律和判定最佳生长季节凡纳滨对虾的体格与月龄的关系,选择1～6月龄凡纳滨对虾各1000只,选择全长、体长、第一腹节背高、第三腹节背高、第一腹节背宽、头胸甲长和体重共7个性状,进行主成分与判别分析。结果表明:各月龄凡纳滨对虾性状之间均呈现显著的正相关(P<0.01),其中以全长与体长的相关性最为明显,1月龄凡纳滨对虾体重与形态性状的相关系数较小。各月龄凡纳滨对虾的主成分有所不同,1～2月龄凡纳滨对虾的第一主成分为长度因子,第二主成分为宽度因子,第三主成分为高度因子;3月龄凡纳滨对虾的第一主成分与1～2月龄凡纳滨对虾一致,但第二主成分为高度因子,第三主成分为体重因子;4～6月龄凡纳滨对虾的第一主成分为体重因子,第二主成分为高度因子,第三主成分为宽度因子。1～3月龄凡纳滨对虾形态性状的增长优先于体重,4～6月龄凡纳滨对虾体重优先于形态性状的增长。错过最佳生长季节的凡纳滨对虾的与体格大小相符的月龄可通过建立的判别式来判断,总的判别准确率为98.98%,其中2～4月龄凡纳滨对虾的判别准确率为100%。

In order to research on the rule of the relative growth of traits of Litopenaeus vannamei and judging the age matching with the size of L.vannamei missing the best growing season,the data acquired by measuring the total length（X1）,body length（X2）,first abdominal segment depth（X3）,third abdominal segment depth（X4）,first abdominal segment width（X5）,carapace length（X6）and body weight（Y）of Penaeus vannamei at different ages in Banqiao Village of Dongfang City,Hanan Province were analyzed by principal component and discriminant analysis.Result shows that the correlation between any two traits of L.vannamei is significant（P〈0.01）at all tested ages.,among which those between the total length（X1）and body length（X2）are relatively larger and those between body weight（Y）and morphometric attributes are relatively smaller.The principal components of L.vannamei at different ages are different.For example,the first principal component of L.vannamei at from one month of age to two months is length factor,the second principal component is width factor and the third principal component is depth factor.Also,for L.vannamei at three months of age,its first principal component is the same as that at from one month of age to two months,but its second principal component is depth factor and its third principal component is body weight factor.Finally,the first principal component of L.vannamei at from four months of age to six months is body weight factor,the second principal component is depth factor and the third principal component is width factor.The results of principal component analysis reflect that the growth of morphometric attributes of L.vannamei at from one month of age to three months takes priority compared with that of body weight,but the growth of body weight of L.vannamei at from three months of age to six months is given priority to compared with that of morphometric attributes.The month age closely related to the size of L.vannamei which has missed the best growing period can be deduced by employing the discriminant equations mentioned in this paper and the results of the discriminant analysis demonstrate that the overall accuracy is 98.98% and those of L.vannamei at two months of age to four months all reach 100%.