河蟹雌雄分养对其亚成体养殖性能和性腺发育的影响

河蟹雌雄单性化养殖是一种新型的养殖方式,尚不清楚雌雄分养对成蟹养殖性能和性腺发育的影响。本研究初步比较了群体养殖条件下雌雄分养和雌雄混养对河蟹亚成体生殖蜕壳率、成活率、增重率、性腺指数和肝胰腺指数的影响,结果表明:(1)无论雌体还是雄体,雌雄分养组的生殖蜕壳速度均快于雌雄混养组,其中单性雌体第15天和20天的生殖蜕壳率显著高于混养雌体组(P0.05);实验过程中,单性雌体组的死亡率一直高于混养雌体组,而单性雄体组20~30 d的累计死亡率低于混养雄体组;(2)就最终成活率而言,单性雌体组和混养雌体组的成活率接近(P0.05),而单性雄体成活率显著高于混养雄体组(P0.05);雌雄分养和雌雄混养对其增重率均无显著影响,雌雄平均增重率均在50%左右;(3)雌雄分养对其性腺指数和肝胰腺指数均无显著影响,生殖蜕壳后25~40 d,雌雄性腺指数分别为7.3%和2.6%左右。综上,雌雄分养可以促进雌体提前生殖蜕壳,提高雄体单养的成活率,且对成蟹增重率和性腺发育均无负面影响。

Effects of mono-sex culture on the culture performance and gonad development of pre-adult Eriocheir sinensis

The mono-sex culture of Chinese mitten crab Eriocheir sinensis is a new culture method, and there is increasing interest in the commercialization of this pond-culture technique because of different nutritional requirement and market time for males and females. However, no available information could be found on the effects of mono-sex culture on the culture performance and gonad development of adult E. sinensis. Therefore, the objectives of this study were conducted to investigate the differences of puberty molting rate, survival, weight gain rate (WGR), gonadosomatic index (GSI) and hepatopancreas index (HSI) among all females treatment (AF), all male treatment (AM) and mixture-sex treatment including mixed females (MF) and mixed-males (MM) by the culture experiment and dissection. The results showed that: (1) Despite of males or females, the puberty molting rate of AF and AM was higher than that of mixed-sex culture treatments. However, the only two significant differences were found at the point of 15 d and 20 d, respectively (P<0.05); during the experimental period, the cumulative mortality of AF was higher than that of MF while the final mortality of AM was lower than that of MM. (2) In terms of survival, there was no significant difference in the survival between AF and MF (P>0.05), while AM had the significanttly higher survival than MM; the mono-sex and mixture-sex culture had no significant effects on WGR, with approxiamtely 50% of SGR after puberty molting for both males and females. (3) As for GSI and HSI, mono-sex culture had no significant effect on them, and the GSI of males and females were 7.3% and 2.6%, respectively during 25-40 days of post puberty molting. In conclusion, mono-sex culture can prompt the female puberty molting earlier, improve the male survival compared to the mixture-sex culture, and no negative effect was found in body growth and gonadal development.