翘嘴红鲌的形态两性异形和雌性生育力

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

实验研究了来自浙江余姚翘嘴红鲌(Erythroculter ilishaeformis)成体的体重、躯干重和16个形态特征指标的两性异形以及雌性个体生育力。结果显示,翘嘴红鲌雌雄个体除背鳍基前距外其余形态学指标以及体重和躯干重均无显著的两性差异,特定体长的雌鱼的背鳍基前距显著大于雄鱼。线性回归分析表明,翘嘴红鲌的怀卵数量与体长和体重呈显著的正相关,由此推断雌鱼主要通过个体体长的增长和体重的增加来提高个体生育力。由以上结果我们推断水生环境因子抑制了生育力选择和性选择对翘嘴红鲌两性异形进化产生影响。

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.