眼斑双锯鱼形态性状与体质量的相关性及通径分析

【目的】评估人工养殖条件下影响眼斑双锯鱼（Amphiprion ocellaris）体质量的形态性状，并建立体质量与主要形态性状的多元回归方程，为眼斑双锯鱼快速生长品系选择育种工作的开展提供参考依据。【方法】以人工养殖的2月龄眼斑双锯鱼为研究对象，准确测定其体质量（W）及全长（L₁）、体长（L₂）、体高（L₃）、头长（L₄）、头高（L₅）、吻长（L₆）、尾柄长（L₇）、尾柄高（L₈）、背鳍前距（L₉）、胸鳍前距（L₁₀）、腹鳍前距（L₁₁）和臀鳍前距（L₁₂）等12个形态性状，运用相关分析计算各表型性状间的相关系数，应用通径分析筛选显著影响体质量的形态性状，并通过多元回归分析构建形态性状与体质量的多元回归方程，分析眼斑双锯鱼形态性状对体质量的影响。【结果】13个表型性状间均存在极显著相关性（P< 0.01），与体质量相关系数最大的是体高（0.965），其次是尾柄高（0.944），与体质量相关系数较小的是吻长（0.730）和尾柄长（0.601）；剔除共线性影响后，通径分析筛选出对体质量影响显著的5个形态性状分别是体高、尾柄高、体长、头长和吻长。其中，对体质量的直接作用（通径系数）排序为体高（0.574）>体长（0.404）>尾柄高（0.284）>吻长（0.108）>头长（-0.358），间接作用（间接通径系数）排序为头长（1.256）>尾柄高（0.667）>吻长（0.621）>体长（0.540）>体高（0.391）；对体质量的单独决定系数排序为体高（0.330）>体长（0.163）>头长（0.128）>尾柄高（0.081）>吻长（0.012）。体质量与体高、尾柄高、体长、头长和吻长等5个形态性状的多元回归方程为W=-0.708+0.085L₃+0.084L₈+0.025L₂-0.090L₄+0.070L₆，R2=0.963。【结论】体高可作为以2月龄眼斑双锯鱼选育快速生长品系的首选目标性状，体长、头长、吻长和尾柄高等变量则可作为辅助选择性状。

Correlation and path coefficient analysis between morphological traits and body weight in Amphiprion ocellaris

【Objective】The aim of this study was to investigate the relationship between body weight and morphological traits in Amphiprion ocellaris under aquaculture condition.The multiple regression equations of body mass and main morphological characters were established to provide a useful reference for the fast-growing selective breeding of A.ocellaris.【Method】In the experiment, individuals of two-month-old A.ocellaris were randomly collected, and body weight(W), total length(L₁), body length(L₂), body height(L₃), head length(L₄), head height(L₅), snout length(L₆), caudalpeduncle length(L₇), caudal-peduncle height(L₈), pre-dorsal length(L₉), pre-pectoral length(L₁₀), pre-pelvic length(L₁₁), pre-anal length(L₁₂) were accurately determined.The correlation coefficients between each trait were calculated by correlation analysis, and the morphological traits that significantly affected body weight were selected by the path analysis method.The multiple regression equation between morphological traits and body weight was constructed by multiple regression analysis to analyze the influence of morphological traits on body weight in A.ocellaris.【Result】The results showed that there was extremely significant correlation among the 13 traits(P< 0.01).Body height had the highest correlation coefficient(0.965) with body weight, followed by body length(0.944), and snout length(0.730) and caudal-peduncle length(0.601) had low correlation coefficient with body weight.After eliminating the collinearity effect, the path analysis selected five morphological traits with significant effect on body weight, which were body height, caudal-peduncle height, body length, head length and snout length.The order of direct effect on body weight(path coefficient) from large to small was body height(0.574) > body length(0.404) > caudal-peduncle height(0.284) > snout length(0.108) > head length(-0.358), the order of indirect effect(indirect path coefficient) from large to small was head length(1.256) > caudal-peduncle height(0.667) > snout length(0.621) > body length(0.540) > body height(0.391), and the order of individual determinant coefficient from large to small was body height(0.330) > body length(0.163) > head length(0.128) > caudal-peduncle height(0.081) > snout length(0.012).The multiple regression equation between body weight and these five morphological traits was W=-0.708+0.085L₃+0.084L₈+0.025L₂-0.090L₄+0.070L₆, R2=0.963.【Conclusion】Body depth is the most important morphological index in the selective breeding of fast-growing parent fish of 2-month-old A.ocellaris.Other variables such as body length, head length, snout length and caudal-peduncle height can be used as auxiliary selection indexes.