中华绒螯蟹2龄早熟和晚熟品系选育第4代(G4) 在成蟹阶段养殖性能的比较

Culture performance of the second-year early-maturing and late-maturing strains of the fourth selective generation of Chinese mitten crab (Eriocheir sinensis) during the adult culture stage

摘要:

为评估选育第4代(G4)的中华绒螯蟹在成蟹阶段的养殖性能和性腺发育情况,以G4中华绒螯蟹2龄早熟和2龄晚熟品系为试验对象,以未经选育的养殖群体作对照,比较了这3个群体的扣蟹在成蟹养殖阶段生长、性腺发育及最终养殖效果的差异。试验结果显示:(1)2个选育品系在成蟹养殖阶段的平均体质量始终高于对照组,其中在9月份和11月份,2龄晚熟雌、雄个体的平均体质量均显著高于对照组(P＜0.05)；(2)2龄早熟雌、雄个体的生殖蜕壳时间均早于其他2组,此外,2龄晚熟雌、雄个体分别在7月25日和8月15日的生殖蜕壳率显著低于另外2组(P＜0.05)；(3)就性腺发育而言,2龄早熟品系在性腺发育期间的性腺指数(GSI)始终较高,而2龄晚熟品系的GSI始终较低,其中在9月25日2龄早熟雌蟹的GSI显著高于另外2组(P＜0.05)；(4)2个选育品系成蟹的最终平均体质量和单位面积产量均显著高于对照组,且晚熟雌蟹的成活率显著高于对照组(P＜0.05)；(5)就规格分布而言,晚熟雄蟹体质量在145.00~169.99 g所占的比例显著低于对照组,而在195.00 g以上的比例显著高于其他2组(P＜0.05)；晚熟雌蟹体质量在80.00~99.99 g所占的比例显著低于对照组,而在140.00 g以上的比例显著高于另外2组(P＜0.05)。结果表明,遗传选育可以有效控制中华绒螯蟹的性腺发育速度及最终体质量。这一结果为2龄早熟和2龄晚熟新品种的申报提供了数据支撑。

Abstract:

This study was aimed to evaluate the culture performance and gonad development of two selected strains of Chinese mitten crab Eriocheir sinensis, i.e. early-maturing strain (EM) and late-maturing strain (LM),by comparing them to the control population without selective breeding. The results showed that:(1)The average body weight of two selective strains were always higher than the control group, which was significantly lower than LM individuals during the period from September to November (P<0.05)；(2)The puberty molting of crabs in the EM group were earlier than other two groups. Among them, the puberty molting of male and female crabs in the LM group were significantly lower than other two groups on August 15 and July 25,respectively;(3) For gonad development, the gonadosomatic index (GSI) of EM and LM individuals was always the highest and the lowest respectively, and the GSI of female EM individuals was significantly higher than other two groups in Sepember 25;(4)The final average body weight and yield of the two selective groups were significantly higher than the control group (P＜0.05),and the survival rate of female LM was significantly higher than the control crabs (P＜0.05);(5)In terms of size distribution, male LM crabs were significantly lower than the control in the range of 145.00~169.99 g, and were significantly higher than the other two groups in the range of ≥195.00 g. Female LM crabs were significantly lower than the control group in the 80.00~99.99 g range, and were significantly higher than the other two groups in the range of ≥140.00 g. The results showed that selective breeding is an effective means to regulate growth performance and gonad development of E.sinensis.