中华绒螯蟹二龄早熟和晚熟品系选育第五代(G5)的生长性能和性腺发育评估

Growth performance and gonad development of the second-year early-maturing and late-maturing strains of the fifth selective generation of Eriocheir sinensis

为评估中华绒螯蟹(Eriocheir sinensis)二龄早熟(EM)和晚熟(LM)品系第五代选育效果,本研究以未选育群体作为对照组,比较了两选育品系与对照组在扣蟹及成蟹养殖阶段的生长性能和性腺发育差异,结果显示:(1)两选育品系在扣蟹养殖阶段的平均体质量与增重率(WGR)均高于对照组,其中8月和10月时LM雄体平均体质量显著高于对照组,且7-9月期间LM品系雌雄扣蟹的WGR均显著高于对照组;(2)两选育品系在成蟹养殖阶段的平均体质量一直高于对照组,且两选育品系中LM品系平均体质量一直高于EM品系,但两选育品系之间并无显著差异;(3)雌雄个体在成蟹养殖阶段的生殖蜕壳高峰期分别为7月25日-9月5日和8月15日-9月25日,在此期间EM品系的生殖蜕壳率高于对照组,LM品系的生殖蜕壳率低于对照组,其中EM品系雌雄个体在8月15日的生殖蜕壳率均显著高于LM品系;(4)就性腺发育而言,EM品系在性腺发育期间的性腺指数(GSI)始终较高,LM品系的GSI始终较低,其中在10月25日EM品系雄体的GSI显著高于LM;综上,经过连续多代选育,中华绒螯蟹二龄EM和LM品系在扣蟹和成蟹阶段的生长性能较对照组均表现出较大提升,EM扣蟹和成蟹最终体质量比对照组高1.34%~7.27%和6.74%~8.19%,LM品系则高7.24%~22.31%和15.76%~16.00%,且EM和LM品系在生殖蜕壳方面比对照组提前和推迟10~15 d左右,EM成蟹性腺指数始终高于对照组,在性腺发育速度方面也得到有效控制。

This study aimed to evaluate the growth performance and gonad development of two selective lines, i.e.,early-maturing population(EM) and late-maturing population(LM),and the control population without selective breeding during juvenile and adult culture stages.The results showed that the average body weight and WGR of the two particular lines were consistently higher than the control during the juvenile culture stage, and the average body weight of LM males was significantly higher than the control between Aug.and Oct.Despite males or females, the WGR of LM was higher than the control between July and Sept.The average body weight of the two selective lines was always higher than the control during the adult culture stage, and LM was higher than EM during the whole adult culture stage.The pubertal molting rate of EM was higher than the control, while LM was lower.The EM’s pubertal molting rate on Aug.15 was significantly higher than LM.In gonad development, GSI of EM was always higher, LM was always lower.And EM males had a higher GSI than LM on Oct.25.In conclusion, after multiple generations of continuous selective breeding, EM and LM of Eriocheir sinensis in both juvenile and adult culture stages had a more significant improvement of growth than the control.The final average weight of EM was 1.34%~7.27% and 6.74%~8.19% higher than the control, while LM was 7.24%~22.31% and 15.76%~16.00% higher.The puberty molting rate of EM was about ten days earlier than the control, while LM was ten days later.GSI of EM was always higher than the control, and the gonad development speed was controlled effectively.This study provided a date reference for the application and subsequent large-scale promotion.