大菱鲆幼鱼表型形态性状与体重之间的关系

Relationship between morphometric attributes and body weight of juvenile turbots Scophthalmus maximus

随机选取1120尾3月龄大菱鲆幼鱼,测量其体长、全长、体高、头长、吻尖至鳃裂前缘长、尾柄长、尾柄高、体厚、体重等9个性状,计算各性状间的相关系数,采用通径分析方法计算以表型形态性状为自变量对体重作依变量的通径系数、决定系数及复相关指数,对各性状的影响大小进行剖分,明确影响大菱鲆三月龄幼鱼体重的主要外部形态性状,为大菱鲆选育提供理论依据和理想的测度指标。结果表明:所测各表型性状与体重之间的相关系数均达到极其显著水平(P<0.01);全长对体重的直接影响(R=0.702)最大,对体重的决定程度(R2=51.84%)最高,是影响体重的主要因素;体高、体厚对体重的直接作用(0.211,0.094)相对较小,主要通过体长的间接作用(0.5558,0.4342)影响体重。所选表型性状对体重的回归系数R2=0.911,表明所选性状是影响体重的主要性状。利用逐步回归分析方法建立以体长、体高、体厚为自变量估计体重的多元回归回归方程为:y=-6.216+1.294x1+0.518x2+1.293x3。

To study the effect of morphometric attributes on body weight of the turbot Scophthalmus maximus, morphometric measurement was taken on 1120 3-month-old turbots sampled in a local company in Yantai, Shandong of China. The attributes used in this study include body length, total length, body depth, head length, length between snout tip and frontal of gill cleft, tail handle length, tail handle height, body width, and body weight. A correlation coefficient matrix was constructed, in which the body weight was used as the dependent variable and other attributes as independent variables for path analysis. The path coefficients （ Pi ）, determination coefficients （ di and dij）, and correlation index （ R^2 ） were calculated, and major morphometric attributes determined. The results showed that all the correlation coefficient between each independent variable and dependent variable （body weight） were significantly different （P 〈 0.01 ）. The total length gave a predominant direct effect （0.720） and determinacy on the body weight, it is the key effective factor, whereas body depth and body width exhibited a slight direct effect （0.211, 0.094） and significant indirect effect （0.5558, 0.4342） on the body weight viatotal length. The high value of multiple correlation index R^2 at 0.911 between morphometric attributes and body weight suggests that the selected attributes are practical. The multiple regression equation relating the body weight was established as y = - 6.216 ＋ 1.294x1 ＋ 0.518x2 ＋ 1.293x3, where y is body weight, x1 , x2, x3 is the total length, body depth, and body width, respectively.