长江水系野生中华绒螯蟹F1不同规格仔蟹在扣蟹阶段养殖性能比较

长江水系野生中华绒螯蟹F_1具有优异的养殖性能,但F_1不同规格仔蟹对扣蟹养殖性能的影响并不清楚。本研究系统地比较了长江水系野生中华绒螯蟹F_1不同规格仔蟹在扣蟹养殖阶段的生长、成活率、早熟率、产量、养成规格和饵料系数等指标。结果表明:(1)生长阶段,小规格组扣蟹的平均体质量始终低于大规格组。就雌体而言,6—7月和8—9月,小规格组扣蟹的增重率(WGR)和特定生长率(SGR)显著高于大规格组(P0.05);就雄体而言,6—7月和7—8月,小规格组扣蟹的WGR和SGR显著高于大规格组(P0.05)。(2)小规格组正常扣蟹平均体质量低于大规格组,成活率较高,但无显著性差异(P0.05)。小规格组最终养成扣蟹无一龄早熟现象,而大规格组则存在一定的早熟率。小规格组饵料系数(FCR)显著低于大规格组(P0.05)。(3)就最终规格分布而言,小规格组养成扣蟹规格主要集中于0～6.00 g,所占百分比为80.09%;大规格组养成扣蟹规格主要集中于3.00～9.00 g,所占百分比为70.56%。长江水系野生中华绒螯蟹F_1不同规格仔蟹在扣蟹养殖阶段养殖性能存在差异,这为野生中华绒螯蟹的种质资源评价和优良性状挖掘提供依据。

Comparison of the culture performance of different size juveniles of wild Chinese mitten crab offsprings during juvenile culture stage

Although wild Chinese mitten crab (Eriocheir sinensis) offsprings in the Yangtze River basin have better culture performance, the culture performance of different size juveniles is still unclear. Therefore, this study was conducted to compare the growth, survival rate, precocious rate, yield, feed conversion ratio (FCR), final mean body weight and size distribution of wild Eriocheir sinensis offsprings during juvenile culture stage. The results illustrated that:(1) During the growth phase of each month, the average body mass of small-size group juveniles was always lower than that of the large-size group. In the case of female crabs, the weight growth rate (WGR) and specific growth rate (SGR) of the small-size group juveniles were significantly higher than those of the large-size group between June-July and August-September (P<0.05). In terms of male crabs, the WGR and SGR of the small-size group juveniles were significantly higher than those of the large-size group between June-July and July-August (P<0.05).(2) The average body mass of normal coin-size juveniles in the small-size group was lower than that of large-size group, but the survival rate was higher than that of large-size group. The yields of the two group juveniles were slightly different, but there was no significant difference (P>0.05). No precocious crabs were finally found in the small-size group.However, the large-size group juveniles had a certain precocious rate. The FCR of small-size group was significantly lower than that of the large-size group (P<0.05). (3) As for the final size distribution, the small-size group juveniles were mainly concentrated from 0 to 6.00 g, and its proportion was 80.09%. The large-size group juveniles were mainly concentrated from 3.00 to 9.00 g, and its percentage was 70.56%. There are differences in the culture performance of different size juveniles of wild Eriocheir sinensis offsprings during juvenile culture stage. This provides reference for germplasm resource evaluation and exploitation.