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一、育苗期间的常见病害 河蟹在整个生活时期都可能发生病害,但在育苗阶段,由于生产方式的高度集约化,幼体处于频繁的蜕皮变态过程中,食性的不断转换,对环境条件的变化尤为敏感,耐受能力较弱。因此,该阶段发病率最高,危害也最大。 1.弧菌病 患病幼体主要表现出体色浑浊,肠道内无食物,活力明显下降,行动迟缓,反应迟钝。趋向反应不明显,大多下沉于水底而死亡。 取患病幼体压片,在10×40倍以上的显微镜下观察,可在体液或组织中发现大量活动
First, the common disease during nursery crabs throughout the life may be disease, but in the nursery stage, due to the highly intensive mode of production, larvae in frequent molting metamorphosis process, continuous conversion of feeding habits, especially for environmental conditions change Sensitive, weaker tolerance. Therefore, the highest incidence of this stage, the most dangerous. 1. Vibriosis diseased larva mainly showed body color turbidity, no food in the intestine, vitality decreased significantly, slow, unresponsive. Trend response is not obvious, most of them sink to the bottom and die. Take the sick larvae tablets, observed at 10 × 40 times the microscope, a lot of activity can be found in body fluids or tissues