Mathematical Analysis of Effects of Morphometric Attributes on Body Weight in Taimen Hucho taimen

The body weight,total length,standard length,fork length,body height,body width,head length,head height,head width,eye diameter,interorbital width and snout length were measured in 900 over 1-year old Hucho taimen juveniles from 20 full-sib families.The correlation index(R2),path coefficients(Pi) and determination coefficients(Di) were calculated based on independent variables of morphometric attributes and dependent variables of body weight by correlation analysis,path analysis and multivariate analysis.There were significant difference in all 11 correlation coefficients between each morphometric attribute and body weight(P 0.05).Exclusion of standard length,fork length and head length attributes that shared the collinear with total length,the path analysis revealed that the eye diameter and snout length had no significant effect on the body weight.Among the remain six attributes,the total length was found to show the significant effect on the body weight with the direct effect efficiency s of 0.5549.Judging by the results of high determination coefficients(R2=0.9643),the six attributes were the key effective factors to the body weight.The path formula was expressed based on the independent variables of total length,body height,body width,head height,head width,interorbital width and dependent variables of body weight by using multivariate analysis as log(body weight) =-3.9130+1.7039 log(total length)+0.2626 log(body height)+0.2740 log(body width)+0.1765 log(head height)+0.3460 log(head width)+0.2624 log(interorbital width).These results provided a theoretical basis with selection of taimen broodstock and measurement of the morphometric attributes in aquaculture.