室内养殖条件下中华绒螯蟹雄性个体的生殖潜力

Reproductive potentiality of individual male Chinese mitten crab(Eriocheir sinensis) under the laboratory-reared conditions

为评判中华绒螯蟹育苗工作亲本投放性比（♀∶♂=2～3∶1）的合理性,通过室内连续交配实验,对雄性个体的生殖潜力进行了研究。结果显示,雄蟹具备完成3次连续交配活动的生殖潜力;个体丧失交配能力前,贡献了超过60%的精子（≥6×109个）等雄性产物;多次交配活动并没有对雌蟹的个体繁殖力产生影响;雌蟹抱卵后,纳精囊亦没有出现明显的偏差;实验条件和基地育苗池个体纳精囊内均还存有一定数量的精子,表明雄蟹提供的雄性产物可以满足雌蟹受精的需要,因此,该性比在实际育苗生产中具有一定合理性,而作为亲本雄蟹的大规格及自身的生殖策略则可能是中华绒螯蟹避免精子限制发生的重要原因,其潜在的精卵比达（1.59～10.86）×10～3∶1。此外,研究成果揭示这个被广泛采用的亲本性比存在进一步优化的可能,可以提升至4∶1。

The Chinese mitten crab Eriocheir sinensis is a commercial important species in China. The aim of the study is on the individual male reproductive potentiality under the laboratory-reared conditions by evaluating the rationality of the parental sex ratio（♀∶♂=2–3∶1） during the process of breeding. The results showed that male has the capacity to complete three successive mating activities; prior to losing mating ability, male has contributed more than 60% semen material including the sperm number of ≥6×109 contained in vasa deferentia; male multiple mating activities have no obvious effect on females＇ fecundities; after egg-carrying, female spermathecal weights displayed no distinct deviations either in the laboratory or field-reared conditions, while both spermathecae still contained certain semen material, which means that male would have provided enough sperm to satisfy females＇ fertilization. Therefore, this parental sex ratio should be proper and practical. Moreover, male big size and reproductive strategy should be two important factors to avoid occurrence of sperm limitation, which make the potential ratio of sperm to egg up to（1.59–10.86）×103∶1. Besides, our study reveals that this sex ratio adopted extensively in process of seed breeding, can be further optimized and elevated to 4∶1.