Path Analysis on Morphological Traits and Body Weight of Oreochromis aureus

For the sake of enhancing breeding efficiency of Oreochromis aureus and identifying clear objects to breed, data for this study were collected from 205 Oreochromis aureus.Their body weight(Y),total length(X1),body length(X2),head length(X3),trunk length(X4),body depth(X5),body width(X6),caudal peduncle length(X7) and caudal peduncle depth(X8) were measured.Path analysis was adopted to calculate correlation coefficient using body weight(Y) as dependent variable and other traits as independent variable from which coefficient of determination and path coefficient were gained.The results indicated that the male Oreochromis aureus correlation coefficients of total length,body length, head length,body depth,body width and body weight all reached significant level(P0.05);the female Oreochromis aureus correlation coefficients of each morphological trait reaching extremely significant level(P0.01) were of positive correlation relationship.The total length,caudal peduncle depth,body width and head length were the critical factors on the body weight of male Oreochromis aureu,while the major factors on the body weight of female Oreochromis aureus were the body width,body length,trunk length,body depth,and total length.The determination coefficients of total length(0.504) played a decisive role in body weigh of male Oreochromis aureus,and the determination coefficients of body width(0.450) mostly affected the body weight of female Oreochromis aureus.In accordance with multiple regression analysis,the morphometric traits reaching the level of significance(P0.05) and body weight were used to establish the multiple regression equations,which were presented as Y=-688.287+2.468X1+9.453X6+0.676X8 in male Oreochromis aureus and Y=-418.506+0.871X1+12.551X6 in female Oreochromis aureus.