Abstract:To study the correlation of biological traits between male and female mantis shrimp (Oratosquilla oratori), eight biological indicators, total length (TL), body length (BL), carapace length (CL), tail fan length (FL), abdominal length (AL), abdominal width (AW), large pincers length (LL), and wet weight (Y) were measured. The influence of morphological traits on body weight was studied using correlation analysis and path analysis. The regression equations representing the effect of morphological traits on body weight were established using the stepwise regression method, and the curve models of seven shape traits and body weight were fitted. The results showed that the variation coefficient of body weight was greater than that of the morphological traits, and quantitative traits such as FL, AW, LL, and Y were significantly different between male and female O. oratori (P<0.01) .The correlation of the quantitative traits reached a very significant level (P<0.01) among the female, male, and mixed populations. In the relationship of morphological traits, the correlation coefficients of TL to BL were largest in the female group, the male group, and the mixed group (0.984, 0.993, and 0.988, respectively); regarding the relationship of morphological traits to body weight, the correlation coefficient of TL to body weight was highest in the female group (0.973), the correlation coefficient of BL to body weight was largest in the male group (0.974), and the correlation coefficient of AW to body weight was largest in the mixed population group (0.969). The greatest direct effect on body weight in females and mixed populations was AW (diameter coefficients of 0.418 and 0.508, respectively), and the direct effect on body weight was the greatest in male BL (diameter coefficient, 0.613). The direct determination coefficient of AW to body weight was the highest in the female group and the mixed population group (0.175 and 0.258, respectively), and the direct determination coefficient of BL to body weight was the highest in the male group (0.376). TL, AW, and CL are mainly considered for the female population, BL and AW are mainly considered for the male population, whereas AW and TL are mainly considered for the mixed population. The regression equations of female, male, and mixed populations with morphological traits as independent variables and body weight as dependent variables are: Y1=–48.499+0.315XTL+1.159XAW+ 0.186XCL(R2=0.978), Y2=–55.987+0.453XBL+1.152XAW(R2=0.959), and Y3=–51.651+1.738XAW+0.274XTL (R2=0.960). The optimal fitting models of morphological traits to body weight of O. oratori include the linear model, power function model, and exponential function model. The same types of optimal fitting models are used except for TL, AL between male and female O. oratoria; in addition, nothing else is the same. This study can provide a theoretical basis for the selection of O. oratori.
