高体鳑鲏的两性异形和不同生长阶段两性形态分化OACHSSCD

To investigate sexual dimorphism and morphological differentiation at different growth stages in Rhodeus ocellatus,this study collected morphological data including body mass,body length,head length,snout length,caudal peduncle length,caudal fin length,and eye diameter from 216 sexually mature individuals(108 males and 108 females).Based on body length,the individuals were divided into four growth stages(S1:<30 mm;S2:30-<40 mm;S3:40-<50 mm;S4:≥50 mm)for statistical analysis.The main findings are as follows:(1)Principal component analysis(PCA)(eigenvalues≥1)extracted three principal components from the six morphological traits and body mass,explaining 75.2%of the total variance.The first principal component(accounting for 32.5%of the variance)exhibited that head length and eye diameter had high positive loading coefficients with morphological traits.The second principal component(explaining 25.3%of the variance)showed that none of the six morphological traits had high positive or negative loading coefficients with body mass.The third principal component(accounting for 17.4%of the variance)showed that caudal peduncle length had high positive loading coefficients,and caudal fin length had high negative loading coefficients.(2)Two-way ANOVA revealed that males had significantly greater body length than females,and the interaction between sex and growth stage had a significant effect on body length.Significant differences between sexes were observed in snout length,head length,and caudal fin length.Significant differences at different growth stages were detected in body mass,body length,head length,eye diameter,and caudal fin length.Furthermore,the interaction between sex and growth stage showed significant differences in body mass,body length,and eye diameter,and no significant differences in other traits.(3)T-tests analysis of sexual differences at the same growth stage indicated significant differences in body length and head length at S1 and S4,in caudal fin length at S2,and in body mass at S4,and no significant differences in caudal peduncle length at any growth stage.The findings suggest that Rhodeus ocellatus exhibits significant sexual dimorphism,and the differences in morphological traits between sexes vary with growth stages after sexual maturity.The morphological differentiation pattern may be jointly driven by sexual selection and energy allocation strategies.