Sexual Dimorphism in Morphology and Female Fecundity of erythroculter ilishaeformis from Rivers in Yuyao

Eighteen morphological traits of Ergthroculter ilishaeformis from rivers in Yuao,Zhejiang Province,including sexual dimorphism and female individual fecundity were measured in this study.Eighteen morphological traits including sexual dimorphism and female individual fecundity of Erythroculter ilishaeformis from the river in Yuyao,Zhejiang Province,were measured in this study.Our results showed that there was no significant difference in other seventeen morphological traits excepted the dorsal fin precoxal length.Adult females of E.ilishaeformis were significantly larger than adult males in dorsal fin precoxal length after accounting for body length.The linear regression showed that the individual fecundity was positively related with body length and body mass.It is suggested that adult females increase the individual fecundity through increasing the body mass and body length.According to our results,we inferred that the aquatic environmental factors restrain the effect of fecundity selection and sexual selection on the evolution of Sexual dimorphism in E.ilishaeformis.