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河蟹疾病是影响池塘养蟹产量的一个不利因素,现将河蟹养殖中常见疾病的症状及防治方法作以下介绍,供养殖户参考。一、蜕壳不遂:在养殖中后期成蟹(每只0.1kg以上)易发生蜕壳不遂。河蟹背甲后缘与腹部交界处出现裂缝,背甲上有明显棕色斑点,常因不能蜕去旧壳而死亡。该病可能与缺乏钙质有关,在养殖中可采用如下方法防治:①全池泼洒生石灰,每月2次,每次每亩水深1m用生石灰10～20kg。②饲料中添加贝壳粉与麦粉拌和,增加动物性饲料的比例,一般经5～7天就可收到良好效果。二、黑鳃病:成蟹的鳃部受感染而变色,左右鳃丝部分呈现暗灰色或黑色,病
Crab disease is a negative factor affecting the production of pond crabs, crab farming is now common disease symptoms and prevention methods for the following introduction, for farmers reference. First, extinction unsuccessful: In the late breeding crabs (each 0.1kg or more) prone to extinction. Crab carapace at the junction of the trailing edge and the abdomen cracks, carapace has obvious brown spots, often because they can not shed the old shell and died. The disease may be related to the lack of calcium in culture can be used as follows prevention and control methods: ① Quanchiposa lime, 2 times a month, every 1m depth of lime 1m with lime 10 ~ 20kg. ② add feed shellfish flour and wheat flour mix, increase the proportion of animal feed, usually 5 to 7 days to receive good results. Second, black gill disease: crab gill infection and discoloration, left gill filaments partially dark gray or black, the disease