The technique of raising crabs

Crabs have been very delicious food since ancient times. Let's take a look at the techniques of raising crabs.

1. Pond conditions

Adequate water source, convenient entry and drainage, good water pollution, clay, sandy soil or sub-sandy soil, good ventilation, conducive to the growth and reproduction of aquatic plants and benthic insects, mussels, water earthworms, etc., the old pond should be thoroughly desilted, the silt should not exceed 20cm, and the pond area should not be too small. The water depth of the pond is maintained at about 0.6fu 1.5 meters all the year round, and the depth varies everywhere, and the shallowest 10cm can be made in the pond slightly above the surface of the water, that is, Crab Island, on which aquatic plants can be transplanted, the pond is not too steep, and the slope ratio is generally below 1RU 1.5, otherwise, the river crab is easy to dig holes and is not conducive to climbing out of the water at night. Artificial caves can also be built.

2. Transplant aquatic plants

The natural yield of river crab mainly depends on the number of aquatic plants and benthos (bait organisms) in the water area. It is an indispensable technical measure to plant aquatic plants in the process of breeding. In addition to supplying vitamin for crabs, growing aquatic plants can also support each other's fighting and concealment, which is an effective measure to improve the survival rate of river crabs in each period. in addition, it can also absorb harmful ammonia nitrogen, carbon dioxide, organic matter, release oxygen and stabilize water quality. The masses often say, "crab size, look at water plants." Therefore, great efforts must be made to plant good aquatic plants for river crab culture in ponds. The main types of aquatic plants are duckweed, Manjianghong, water hyacinth, water floating lotus, verticillium verticillata, goldfish algae, bitter grass, water peanut, etc., pay attention to disinfection and prevention when transplanting.

3. Escape prevention facilities

Escape prevention facilities mostly use plastic film, but also use cement board, depending on their respective conditions.

4. Clear the pond and disinfect

Generally in the first half of the release of seedlings with monthly quicklime pond disinfection, the dosage of 75 kg per mu. On the one hand, it can kill enemy organisms, on the other hand, it can improve the bottom of the pond, increase the content of calcium ions in water, and promote the molting growth of river crabs. Fertilize in time after receiving water, cultivate algae and basic bait, transparency is generally maintained in 40-50cm, if tadpoles or frog eggs are found to be removed in time, so as not to compete for food and harm young crabs.

5. Release seedlings

In the selection and purchase of seedlings, the crab seedlings produced in the Yangtze River system are the best, with neat specifications, complete steps, strong physique, active crawling, no injury and no disease.

Seedling release and density, pay attention to temperature difference when releasing seedlings. Seedlings purchased from other places can not be put directly into the pond. Soak in water for 3 minutes, take out and place for 10 minutes, repeat 2murl 3 times. After the young crabs gradually absorb enough water and adapt to the water temperature, put them into the pond, which can improve the survival rate.

Density: at present, most of them are mixed culture, especially the mixed culture of fish, shrimp and crabs, the economic benefit will be higher. The density can be controlled within 1500 / mu and the specification is 120mur150 / kg. If the conditions are poor or shrimp culture can appropriately reduce the amount of seedlings.

6. Daily management

(1) feeding: the whole process of intensive culture in the pond mainly depends on artificial feeding, so the type, quality and quantity of feed have a great influence on the growth and development of river crab. The principle of reasonable matching of concentrate, green and coarse should be adhered to when feeding. Animal concentrate accounts for 40%, aquatic plants account for 35%, and other plant feeds account for 25%. There are three main types of feed: full-price special compound feed for river crabs. (2) animal nature: small mixed fish of sea and fresh water, carcasses of animals, snails, mussels, blood of livestock and poultry, fish meal, silkworm pupa, etc.; (3) plant: aquatic plants, duckweed, water peanuts, bitter grass, verticillium verticillata, commodity feed: potato, Ma Ling potato, cereal, wheat bran, bran, etc.

Conclusion: there are many ways to raise crabs. If you can cultivate crabs better and more carefully, you will certainly be able to raise them well, but you must pay attention to the methods of breeding. Only in this way can you produce better economic benefits.