Disease control techniques of river crab in winter

Removal of silt from the bottom of the pool

The main components of silt are large amounts of residual bait, organic matter, dead animal carcasses and biological excrement. Too much silt can easily lead to the deterioration of water quality in summer, and a large amount of organic acid, hydrogen sulfide and ammonia will be produced to inhibit and harm the growth and survival of river crabs, especially pathogenic microorganisms such as bacteria and parasites exist in the silt, once the conditions are suitable, all kinds of pathogens are rampant. Therefore, take advantage of the idle time of the crab pond in winter to drain the water of the pond and remove all the silt from the bottom of the pond mechanically or manually.

Frozen solarization pool bottom

After cleaning the crab pond, straighten out the ditch, pump water regularly with machinery, and try to make the bottom of the pond go through freezing and sunlight for about a month, so as to improve the soil condition of the bottom of the pond and let some pathogens be killed by freezing and sunlight. Create a good ecological environment for the growth of crabs in the future.

Build up the drainage system

In addition to considering sufficient water flow, the physical and chemical factors of the water are in line with the growth of crabs, free from pollution and pathogens, but also pay attention to the mutual infection and repeated infection caused by the same canal for drainage, so it is required that each crab pond can discharge the water separately.

Carry out drug disinfection

20 days before stocking, crab fry were strictly disinfected with quicklime and bleach powder. Quicklime was disinfected with 75 kilograms per mu, quicklime water was sprinkled in the whole pool, and bleach was disinfected with 15 kilograms per mu.

Do a good job of disinfecting crab bodies

Disinfect the crab seedlings with appropriate medicine before going into the pond. It is commonly used to soak in potassium permanganate solution with a concentration of 15 mg per liter for 20 min or 10 mg bleach solution per liter for 10 min.

Transplanting aquatic plants

Aquatic plants can not only provide habitat and molting environment for river crabs, but also provide fresh and delicious plant feed, reduce the content of ammonia nitrogen in water, increase oxygen and improve water quality. Among the aquatic species, submerged plants are bitter grass, small grass, etc., and phytoplankton are water peanuts, duckweed, and so on. These plants have to be sown, transplanted or transplanted in winter and spring, so that the crab pond coverage rate is more than 60%.