Abstract:Thirteen morphological traits: Total length (X1), body length (X2), carapace length (X3), carapace width (X4), carapace height (X5), first abdominal segment length (X6), first abdominal segment width (X7), first abdominal segment height (X8), sixth abdominal segment length (X9), sixth abdominal segment width (X10), sixth abdominal segment height (X11), tail segment length (X12), and tail fan length (X13) were measured to explore the relationship between the morphological traits and body weight (Y) of Trachypenaeus curvirostirs. The relationship between the traits was studied using path analysis and gray correlation analysis. The results showed that the biological indicators values of females were greater than those of males. There was a highly significant positive correlation between the traits of females and males (P<0.01), and the correlation coefficients of X2 to Y were the highest (0.972 and 0.969, respectively). Path analysis and determination coefficient analysis showed that X2 had the highest direct effect (path coefficients: 0.443 and 0.519, respectively) and direct determination coefficient on Y for the females and males, X7 (sum of indirect determination coefficients = 0.750) and X12 (0.887) had the highest indirect effect on Y for the females and males respectively. The co-determination coefficient of X2 and X5 was the highest (0.167) for the females, while that of X1 and X2 was the highest (0.248) for the males. The stepwise regression method was used to establish multiple regression equations for morphological traits and Y in both female and male populations. The equations were Y1＝–14.563+0.133X2+0.374X7+0.282X5+0.225X13 (R2=0.978) and Y2＝–7.947+0.092X2+0.309X4+0.203X10+0.036X1–0.087X12 (R2=0.980), respectively. The average correlation coefficient of morphological traits to Y for females was between 0.868 and 0.941, and that of the males was between 0.793 and 0.906. For the same morphological traits, the average value of the correlation coefficient and Y for the females was greater than that of the males. The correlation degree was the highest between X2 and Y for the males and females. The results of the path analysis and gray correlation analysis were not exactly the same. A comprehensive comparative analysis showed that during T. curvirostirs breeding, X2 can be used as the main selective trait for males and females. X5 and X7, X4 and X1 can be used as assisted selective traits for females and males, respectively.
