Path analysis of morphological traits effects on body weight of five-month-old grouper Epinephelus coioides
ZHAO Wang1,2, YANG Rui1,2, HU Jing1,2, YANG Qi-bin1,2, MA Zhen-hua1,2, YU Gang1,2
1.Tropical Fisheries Research and Development Center, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Sanya 572018, China; 2.Key Laboratory of South China Sea Fishery Resource Exploitation & Utilization, Ministry of Agriculture, Guangzhou 510300, China
Abstract: The relationship between morphological traits and body weight was analyzed using body weight (Y) and 11 morphological traits (X1-X11) from five-month-old grouper Epinepheluscoioides and multiple regression equations as well as filling equations were established by correlation coefficients, path coefficients and determination coefficients. A significant positive correlation between morphological traits and body weight was observed, with very significance (P<0.01). The path analysis revealed that interorbitat(X7) displayed the maximal positive direct effect (0.412) on body weight, and follow by caudal peduncle height(X10), body height(X5) and bod width (X6). Trunk length (X2) affected body weight indirectly via X5, X6, X7 and X10. The determination coefficients revealed that the total decision coefficient of five morphological traits to body weight was 0.915, indicating that those morphological traits were the main factors influencing body weight.The regression equation of morphological traits to body weight was expressed as:Y=-214.67+1.033X5 +1.519X6+7.548X7+3.101X10 in 5 month old grouper. The findings indicate that trunk length, body height, body width, interorbitat and caudal peduncle height should be considered for the indirect selective breeding of body weight in selective breeding of five-month-old group besides the chief factor body weight.
2017, Vol. 32 
