中国对虾形态性状对体重影响的通径分析

Path analysis of effects of morphometric attributes on body weight of Fenneropenaeus chinensis

测定519尾5月龄中国对虾体长、全长、体重、头胸甲长、头胸甲宽、第1腹节高、第5腹节高、第6腹节长、额剑上刺数目、额剑下刺数目10个指标,计算性状间的相关系数。采用通径分析方法计算以形态性状为自变量对体重作依变量的通径系数、决定系数,对各性状的影响大小进行剖分。结果表明,头胸甲宽对体重的直接影响最大,额剑上刺数目、额剑下刺数目对体重的直接影响较小。经显著性分析,剔除与体重多元相关不显著的第1腹节高、第6腹节长、额剑上刺数目、额剑下刺数目,建立体长、全长、头胸甲长、头胸甲宽、第5腹节高与体重的多元回归方程。

519 five-month-old Fenneropenaeus chinensis were collected for measuring the morphormetric attributes, including the body weight, body length, total length, carapace length, carapace width, first abdominal segment height, fifth abdominal segment height, sixth abdominal segment length, number of upper frontal eminence spine and number of lower frontal eminence spine. The correlation coefficients among the attributes were calculated, and then path analysis was conducted by taking the body weight as a dependent variable, and other nine morphometric attributes as independent variables. The results showed that the carapace width weighted most with the body weight; the body length and the total length followed. So the three above-mentioned parameters could be regarded as the key influence factor, the second and third significant indirect effect factor, respectively. As the first abdominal segment height, the sixth abdominal segment length, the number of lower frontal eminence spine carapace height and the number of upper frontal eminence spine had insignificant direct effect on the body weight, so all of them could be excluded from the multiple regression equation. At this rate, the multiple regression equation, viz. the relation of body weight to body length, total length, carapace length, carapace width and fifth segment height, was established.