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河蟹生长是伴随每一次正常脱壳而生长的。人工养殖改变了河蟹生长的自然规律和自然环境,人为因素和环境因素的影响导致河蟹脱壳不遂死亡。特别是开春后幼蟹生长时的首次脱壳,因患烂肢、腐壳、水霉等复合病症导致幼蟹脱壳不遂而大批死亡。笔者根据多年来养殖、研究,总结导致脱壳不遂症的原因和防治方法,供大家参考,不足之处请指正。一症状:病蟹头胸甲后缘与腹部交界处或侧线出现裂口,但不能脱去旧壳或脱出几只附肢而头胸甲不能脱出,有的即使脱出旧壳,新壳长时间也无法变硬而死亡。
Crab growth is accompanied by every normal shelling and growth. Artificial breeding has changed the natural law of crab growth and natural environment, human factors and environmental factors lead to calamine shelling unsuccessful death. Especially after the spring crab growth when shelling for the first time, due to suffering from limbs, rot, water mold and other complex diseases led to shelling shelling and died in large numbers. According to the author over the years breeding, research, summarize the causes of lead and cause of shelling and prevention methods, for your reference, please correct me shortcomings. A symptom: Crab carapace posterior margin and abdomen junction or lateral line of the gap, but can not take off the old shell or prolapse of a few appendages and the carapace can not prolapse, and some even if the prolapse of the old shell, the new shell for a long time Can not harden and die.