Correlation and path coefficient analysis between morphometric traits and body weight in Leptobarbus hoevenii

【Objective】To analyze the correlation between body weight and morphological traits of Leptobarbus hoeve-nii in artificial culture,and to provide theoretical basis for the selection and breeding of excellent morphological traits of L.hoevenii.【Method】In this study,116 4-month-old L.hoevenii samples were measured under artificial feeding condi-tions,and including 7 traits:body weight(Y),full length (X₁),body length(X₂),head length(X₃),carapace length(X₄),body height(X₅) and body width(X₆).Correlation analysis and path analysis were used to screen the main traits affecting body weight,and multiple regression equations were constructed by stepwise regression analysis.【Result】There were ex-tremely significant positive correlations(P<0.01) between morphological traits (full length,body length,head length,carapace length,body height and body width) and body weight in L.hoevenii.The results of the path analysis showed that four morphological traits,including full length,body length,body height and body width,were the main traits affecting the body weight of L.hoevenii.The magnitude of the direct effect on body weight was body length(0.364)>full length(0.291)>body height(0.245)>body width(0.143),and the indirect effect was body height(0.645)>full length(0.644)>body width(0.589)>body length(0.587).The analysis results of determination coefficients(R²) showed that the sum of direct R² and indirect R² of full length,body length,body height and body width to body weight was 0.941,which was greater than 0.850,indicating that the body weight of L.hoevenii was mainly determined by these four morphological traits.Finally,multiple regression equations were established for L.hoevenii,that was Y=-94.861+2.842X₁+4.385X₂+8.089X₅+6.002X₆,(R²=0.946).The four morphological traits,including full length,body length,body height and body width,were fit-ted with body weight respectively.The fitting results showed that the best-fitting models of full length,body length,body height and body width were cubic function,power function,power function and cubic function,with the equations Y=0.265X₁³-0.003X₁²+8.819,Y=4.278X₂^0.290,Y=0.766X₅^0.383,Y=0.032X₆³+1.044,corresponding to R² of 0.892,0.925,0.817 and 0.552 respectively.【Conclusion】In the production and selection of L.hoevenii,body length can be used as the main target trait for selection,while full length,body height and body width can be used as secondary traits for selection.