不同月龄哲罗鲑主要形态性状与体重的关系

The Relationship between Main Morphometric and Body Weight of Taimen(Hucho taimen) at the Different Months

为确定影响哲罗鲑（Hucho taimen）体重的主要形态性状，随机选取5个生长阶段共计710尾哲罗鲑为实验对象（3月龄240尾、6月龄180尾、12月龄110尾、18月龄90尾、36月龄90尾），测量其体重（y）、体长（x1）、体宽（x2）、体高（秘）、头长（x4）、眼径（x5）、尾鳍长（x6）、尾鳍高（x7）、尾柄高（x8）9个性状。通过相关分析、通径分析和回归分析，计算相关系数、通径系数和决定系数，获得相关回归方程，对不同月龄问的形态性状对体重的影响程度进行了比较分析。结果表明，3月龄、6月龄、18月龄和36月龄个体体长对体重的直接作用较大，12月龄个体则是体宽对体重的影响较大。利用逐步回归分析方法，以体重为依变量（y），形态性状为自变量（x1～X8），建立了哲罗鲑不同月龄最优多元线性回归方程分别为：y3=-14．911＋1．561X1＋3．448X2＋5．232X3；Y6=-70．321＋5．192x1＋0．962X2＋0．473X3；Y12=-217．446＋7．129X1＋23．147X2＋44．055X3；Y18=-891．041＋20．234X1＋65．786x2＋53．266X3；Y36=-5748．099＋88．187Xl＋301．984X2＋66．702x7。该研究结果为哲罗鲑选择育种的具体应用提供了重要参考依据。

In order to study the effects of main morphological traits on body weight in Taimen （Hucho taimen）, a total of 710 individuals （240 individuals of 3 month old, 180 individuals of 6 month old, 110 individuals of 12 month old, 90 individuals of 18 month old, 90 individuals of 36 month old） were randomly sampled for measuring the metric traits, including the body weight y, body length x1, body height x2, body depth x3, head length x4, eye diameter x5, caudal fin length x6, caudal fin height x7, caudal peduncle height x8. In order to study the effects of metric traits on body weight, the correlation analysis, path analysis and determination coefficients were calculated and multivariate regression equations were obtained. The results showed that the variation coefficient of bodyweight in different months old Taimen was the greatest, which could be achieved 25.52%, 17.92%, 24.99%, 18.45%, 13.03%, respectively （Table 1）. The correlation coefficients between morphological traits and body weight were range from 0.017 to 0.963 （Table 2）. The normality test results indicated that the 5 groups of samples data were considered as belonging to Gauss distribution by Shapiro-Wilk test and non-obvious discrimination by ANOVA （P 〉 0.05） （Table 3）. As shown in Table 4, body length was the most important trait affected the body weight of 3, 6, 18 and 36 months old Taimen, and the body width was the most important trait affected the body weight of 12 months old Taimen. The results of determinant coefficients were consistent with that of path analysis （Table 5）. The multiple regression equations were established as Y3 = - 14.911 ＋ 1.561 x1 ＋ 3.448 x2 ＋ 5.232 x3 in 3-month-old Taimen, Y6 = - 70.321 ＋ 5.192 x1 ＋ 0.962 x2 ＋ 0.473 x3 in 6-month-old Taimen, y12= - 217.446 ＋ 7.129 x1 ＋ 23.147 x2 ＋ 44.055 x3 in 12-month-old taimen, Y18 = - 891.041 ＋ 20.234 x1＋ 65.786 x2 ＋ 53.266 x3 in 18-month-old Taimen, Y36= - 5748.099 ＋ 88.187 x1 ＋ 301.984 x2 ＋ 66.702 x7 in 36-month-old Taimen, respectively. Above conclusions could provide important references and foundations for the selective breeding of taimen.