一龄四指马鲅形态性状对体重的影响分析

在人工养殖的一龄四指马鲅中随机选取236尾,测量其全长、体长、体重、体高、体厚等11个表型性状,以表型性状为自变量,采用通径分析计算体重为因变量的决定系数、通径系数及复相关指数。然后比较各个表型性状对体重的影响大小,确定各表型性状中影响一龄四指马鲅体重的主要外部形态性状,为四指马鲅选育提供理论依据和测量指标。结果表明:体重与所测定的表型性状的相关系数都达到了其显著水平(P0.01);叉长对体重的直接影响(0.696)最大和决定程度(48.44%)最高,是影响体重的主要因素。体重与实验研究中所选表型性状的复相关系数为R2=0.909,表明实验所选性状是主要影响体重的表型性状。以体高、体厚和叉长为自变量,利用逐步回归分析方法,建立估计体重的多元回归方程为:y=-96.045+6.231x3+7.636x8+9.609x7。

Effects of Morphometric Attributes on Body Weight for One-year-old Eleutheronema tetradactylum

To study the effect of morphometric attributes on body weight of the Eleutheronema tetradacty-lum, morphometric measurement was collected from one-year-old 236 E. tetradactylum. The attributes used in this study include full length, body length, fork length, trunk length, head length, snout length, body width, body height, tail handle height, tail handle length, body weight. A correlation coefficient matrix was construct-ed, in which the body weight was used as the dependent variable and other attributes as independent variables for path analysis. The path coefficients, determination coefficient and correlation index were calculated, and major morphometrie 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 fork length gave a predominant direct effect （0.696） and determinacy on the body weight. It is the key effective factor. The high value of multiple correlation index R at 0.909 between morphometric attributes and body weight suggests that the selected attributes are practical. The multiple regression equation relating the body weight wag estab-lished as y=-96.045＋6.231x3＋7.636x8＋9.609x7.