Correlation and Path Analysis of Morphological Characters of Lutrariasieboldii at Different Months of Age on Body Mass in Beibu Gulf of Guangxi

To understand the relationship between morphological traits and body weight in different months of age, we randomly selected 200 samples at 3 months (13.83 ± 4.25 mm), 200 samples at 6 months (33.21 ± 4.53 mm) and 98 samples at 24 months (94.17 ± 8.50 mm) to study the effects of multiple regression analysis and path analysis on body weight. Partial correlation test and variance expansion coefficient were used to exclude the characters with no significant effect on body weight and the characters with multiple collinearity. The linear regression equations of the body weight of L. sieboldii at 3 months, 6 months and 24 months were constructed by stepwise regression method. The results of regression analysis showed that the phenotypic traits of seashells at each month old had significant or extremely significant effects on body weight except the height of seashells at 24 months old. The results of path analysis showed that shell length had the greatest effect on the body weight of 3-month-old juveniles and 24-month-old juveniles, while shell width had the greatest effect on the body weight of 6-month-old juveniles. The total coefficient of determination ( R 2 ) of each month was greater than 0.85. The regression equation of morphological traits on body weight of L. sieboldii at different months of age was as follows: W 3 = −0.744 + 0.027SH, R 2 = 0.916; 6-month-old shellfish: W 6 = −9.217 + 0.185SL + 0.128SH + 0.535SW, R 2 = 0.853; 24-month-old shellfish: W 24 = −212.727 + 1.872SL + 2.748SW, R 2 = 0.850. Guangxi beibu gulf L. sieboldii different months each morphological characters influence on body quality is different, L. sieboldii body quality breeding goal, Shell height should be selected for 3-month-old shellfish. Shell width was the main selection trait of 6 month old shellfish, while shell height was also considered. Shell length was the main selection trait and shell width was the auxiliary selection trait in 24-month-old shellfish. The results provided basic data for the breeding and selection of parental shells in Beibu Gulf of Guangxi.