Effect of Growth Traits on Body Weight of the New Breeds of Litopenaeus vannamei

Key words: 
• Litopenaeus vannamei /
• correlation analysis /
• regression analysis /
• path analysis

Abstract: The 8 growth traits of Litopenaeus vannamei at different stages,i. e. body weight（ y）,total length（ x₁）,body length（ x₂）,carapace length（ x₃）,first abdominal segment height（ x₄）,first abdominal segment width（ x₅）,third abdominal segment height（ x₆） and the third abdominal segment width（ x₇） were determined by measuring,and the correlation coefficients between the traits,path coefficients and determination coefficients were calculated by using the correlation analysis,regression analysis and path analysis. The correlation analysis indicate that the correlation coefficients between any two of the 8 growth traits are significant（ P ＜ 0. 01）. A multiple regression equation of the body weight（ y） over the body length（ x₂）,total length（ x₁）,the third abdominal segment width（ x₇） and the first abdominal segment width（ x₅） is established by stepwise regression analysis: y = 0. 069x₁+ 0. 202x₂+ 0. 336x₅+ 0. 577x₇- 28. 026（ R²= 0. 955）. The path analysis show the body length had the highest direct effect on body weight,followed by the total length,the third abdominal segment width and the first abdominal segment width. The combination of the total length and the body length had the highest effect on the body weight,followed by the combination of both body length and the third abdominal segment width.