Path Analysis and Grey Correlation Analysis of Morphometric Traits to Body Weight of Exopalaemon modestus

The Siberian prawn Exopalaemon modestus is a commercial freshwater shrimp with high nutritional value in China. To analyze the influence of morphometric traits on the body weight of E. modestus and identify effective indicators for breeding programs of E. modestus , we analyzed the correlations between 12 morphometric traits and body weight using correlation analysis, path analysis, multiple regression analysis, and grey relational analysis. Path analysis showed that body length (BL), carapace height (CH), carapace width (CW), and abdominal width (AW) significantly affect body weight (BW) directly ( P < 0.05). BL had the most significant direct effect (0.721) on body weight. The total determination coefficients of four significant morphometric traits on body weight were 0.906 (>0.85), indicating that substantial morphometric traits explained 90.6% of BW variation. The regression equation was constructed as BW=-1.666+0.049BL+0.045CH+0.035CW+0.021AW ( P < 0.01, R² = 0.906). Grey relational analysis identified that the trait most correlated with BW was BL (relational grade = 0.952), followed by carapace length (CL), abdominal length (AL), and CH. Combined with path analysis and grey relational analysis, BL and CH were the key morphometric traits influencing the body weight of E. modestus . These results provided references for candidate morphometric traits for E. modestus selective breeding programs.