Prevention and treatment of hairy phenomenon of cultured river crab

In the process of growing, farmed river crabs sometimes grow hair on the head, chest and abdominal limbs, making the surface of the crabs very dirty, slow, anorexia, malnutrition, breathing difficulties, chelate feet do not clip people, or even can not shell and die. The cause of this situation is mainly caused by the disease of river crabs, which must be prevented as soon as possible. The earlier the prevention and control, the better the effect, and the loss can be avoided. Which diseases will appear hairy phenomenon and how to prevent and cure it?

One is water mildew. The hyphae of water mold are grayish-white cotton floc, which can produce hair on the crab. The cause of the disease is related to the excessive fertilizer, lack of freshness, less water injection and mechanical damage to the crab body in the crab pond. Control method: crab pond with an average water depth of 1 meter, with 333 grams of dichlorohydantoin per mu, sprinkled with water throughout the pond.

The second is persistent ciliosis. Constrictor, cumulus and other parasites are parasitic or attached to the dorsal shell, foot and gills of river crabs to form fluffy. The cause of the disease is that the water quality of the crab pond is too fat or does not change the water for a long time. Control method: the average water depth of the crab pond is 1 meter per mu. 500 grams of insecticides such as Xianzhongjing or Shachongjing can be sprinkled on the whole pond.

The third is filamentous algae disease. Filamentous algae are attached to the body surface of river crab, which makes the body surface of river crab grow long green filamentous villi, and the villi bend irregularly. The cause of the disease is related to excessive fertilizer of water quality, pH value less than 7.5, moss growing in the pond and so on. Control methods: the crab pond with an average water depth of 1 meter was sprinkled with 15 ~ 20 kg of raw lime water in the whole pool to increase the pH value, and 500 grams of chelated copper was sprinkled in the whole pool, or 200 grams of moss was mixed with the whole pond, and then partially changed the water after 8 hours.