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长江野生扣蟹在成蟹养殖阶段具有优异的养殖性能,但是野生大眼幼体在成蟹养殖阶段的养殖效果却不清楚。因此,本研究系统比较了野生和人工繁育大眼幼体养成的扣蟹(蟹种)在成蟹养殖阶段的生长、性腺发育、成活率、产量、饲料系数、成蟹平均体重及规格分布。结果显示:(1)无论是雌蟹还是雄蟹,野生群体中后期的平均体重显著大于人工繁育群体。野生群体雄蟹在5-6月和7-8月增重率(WGR)和特定生长率(SGR)显著高于人工繁育群体,野生群体雌蟹在8-9月WGR和SGR也显著高于后者(P<0.05)。(2)尽管野生群体最终成蟹规格显著大于人工繁育群体(P<0.05),但成活率略低于人工繁育群体,故两群体的最终成蟹产量基本一致(P>0.05)。(3)就最终成蟹规格分布而言,野生群体大规格雄蟹(体重≥175 g)和雌蟹(体重≥125 g)比例多于人工繁育群体,而中等规格雄蟹(体重125~174.9 g)和雌蟹(体重100~124.9 g)的比例低于人工繁育群体。因此,长江水系野生大眼幼体在成蟹阶段的养殖性能优于人工繁育大眼幼体,可以进一步发掘其优异种质资源,进行中华绒螯蟹良种培育。
Wild crabs in the Yangtze River have excellent breeding performance in crab farming stage, but the breeding effect of wild large-eyed larvae in crab farming stage is not clear. Therefore, the present study systematically compared the growth, gonadal development, survival rate, yield, feed conversion coefficient, crab average body weight and size distribution of the crabs (crabs) grown in the wild and artificially cultured giant eyed larvae during crab farming. The results showed that: (1) The mean body weight of the wild group was significantly greater than that of the artificial breeding group in either the female crab or the male crab. The WGR and SGR of wild male crabs in May-June and July-August were significantly higher than those in artificial breeding groups, and the WGR and SGR of wild-type female crabs in August-September were significantly higher than that of artificial breeding groups The latter (P <0.05). (2) Although the final crab specifications of wild populations were significantly larger than that of artificial breeding groups (P <0.05), the survival rate of wild populations was slightly lower than that of artificial breeding groups, so the final crab yields of two groups were basically the same (P> 0.05). (3) For the distribution of final crab size, the proportion of large-size male crab (weight≥175 g) and female crab (weight ≥125 g) in wild population was higher than that of artificial reproduction group, while the average male crab (weight 125 ~ 174.9 g) and female crab (weight 100 ~ 124.9 g) than the artificial breeding population. Therefore, the aquaculture performance of Yangtze River aquatic larvae in crab stage was better than that of artificial larvae, which could further explore its excellent germplasm resources and breed elite crab breeding.