4月龄军曹鱼幼鱼形态性状与体质量的相关性及通径分析

为了研究4月龄军曹鱼(Rachycentron canadum)幼鱼的形态性状对体质量的影响效应。在实验中,随机选取该月龄幼鱼115尾,先逐一称其体质量(g)和测量其9个形态性状全长(X_1)、体长(X_2)、头长(X_3)、吻长(X_4)、体宽(X_5)、眼间距(X_6)、体高(X_7)、尾柄长(X_8)及眼后头长(X_9), cm],然后统计分析获得性状间的相关性、通径系数和决定系数,并进一步构建形态性状和体质量的回归方程。结果表明,本实验中所测的9个形态指标,与体质量间的相关性均达到了极显著水平(P0.01);在通径系数分析中,3个形态性状(X_2、X_3和X_9)对体质量的直接作用达到极显著水平(P0.01),而它们的直接作用均小于间接作用,反映多形态性状联合效应成为影响军曹鱼体质量的主要因素。以体质量为因变量(Y),X_2、X_3和X9为自变量,采用逐步线性回归的方法,建立的回归方程为:Y=–483.321+12.899X_2+36.818X_3+32.666 X9。该回归方程中总决定系数为0.919,认为方程中X_2、X_3和X_9这3个形态性状是4月龄军曹鱼幼鱼体质量的主要影响因素。本研究结果可为军曹鱼人工育种提供理想的测度指标。

Correlatioin and path coefficient analysis on body weight and morphometric traiths of four-month-old juvenile cobia (Rachycentron canadum

The relatioship between morphological traits and body weight of juvenile cobia (Rachycentron canadum) was analyzed in this study. 115 individuals of 4-months aged cobia were randomly selected and 9 morphological traits (cm) including the total length (X₁), standard length (X₂), head length (X₃), snout length (X₄), body width (X₅), eyes interval (X₆), body depth (X₇), tail handle length (X₈), head length after eyes (X₉), and body weight (Y, g) were measured.The correlation coefficients, path coefficients and decision coefficients were calculated, and then the effects of morphometric traits on body weight was analyzed.The results showed that the correlation coefficients between each morphological trait and body weight achieved highly significant levels (P<0.01)The path coefficients of three morphometric attributes (X₂, X₃, X₉) to body weight reached significant difference (P<0.01) level. The direct effects from three morphometric attributes (X₂, X₃, X₉) to body weight were less than their indirect effects, indicating that the main influencing factors of body weight were composed of multiple morphological traits. Based on path coefficients, the multiple linear regression model equation on the effects of body weight was established as Y=-483.321+12.899 X₂+36.818 X₃+32.666 X₉. The body weight and morphological traits were highly correlated (R²=0.919). This paper may provide a theoretical method for the measurement of cobia in selective breeding.