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

Abstract:

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.