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采用群体选育、养殖实验和定期采样的方法,比较了中华绒螯蟹二龄早熟和晚熟选育群体第三代(G3)和非选育群体在扣蟹阶段的生长、成活率、平均体质量、体质量分布比例和产量,结果显示:(1)二龄早熟雌体在7-8月和9-10月的增重率(WGR)及特定增长率(SGR)显著高于二龄晚熟雌体(P<0.05);无论雌体还是雄体,二龄晚熟群体在7-10月总体生长速度显著低于对照组(P<0.05),整个实验期间3群体的生长速度大小顺序为:对照组>早熟G3>晚熟G3(P>0.05);(2)二龄早熟和晚熟群体G3在扣蟹阶段的成活率接近,但二龄晚熟群体的成活率显著高于对照组扣蟹;二龄早熟群体G3最终扣蟹平均体质量显著高于晚熟扣蟹,对照组居于两者之间,3组扣蟹产量高低顺序为:早熟G3>晚熟G3>对照组;(3)就扣蟹体质量分布而言,3群体扣蟹体质量主要集中于小于3 g和3~6 g这两个体质量范围内,晚熟G3在小于3 g和3~6 g两个体质量范围内比例最高。综上,二龄早熟群体G3在扣蟹阶段具有生长速度快、扣蟹平均体质量大和单产高的优点,二龄晚熟群体G3在扣蟹阶段的成活率显著高于对照组,两选育群体G3在扣蟹养殖上均具有一定的优良性状。
The population growth, survival rate and mean body length of the third generation (G3) and non-selected groups of Eriocheir sinensis in second-instar and late-maturing breeding population were compared by population breeding, breeding experiments and regular sampling. The results showed that: (1) The WGR and SGR of the second instar premature female in July-August and September-October were significantly higher than those in the second-age late-maturing (P <0.05). The growth rate of late-mature population was significantly lower than that of the control from July to October (P <0.05), both in female and male. The growth rates of the three groups during the whole experiment were as follows: (P> 0.05). (2) Survival rate of G3 in the second instar and late-maturing groups close to crab stage, but the survival rate of late-maturing late-maturing population was significantly higher than that of the control group The average body weight of the final crabs in the early-maturing group G3 was significantly higher than that of the late-mature crabs, while the control group lived between the two groups. The order of the yield of the crabs in the three groups was: precocious G3> late-ripe G3> control group; (3) In terms of mass distribution, the population crab body mass of 3 groups mainly concentrated in the two body mass ranges of less than 3 g and 3 ~ 6 g, late-maturing G3 was less than 3 g and 3 ~ 6 g The highest amount within the range of the ratio. In conclusion, the G3 of the second-instar group had the advantage of fast growth, average body weight of the crab, and high yield per unit yield in the crab stage. The survival rate of G3 in the second-late-maturing group was significantly higher than that in the control group G3 in crab breeding have some good traits.