Efficient crayfish culture technology in low-lying fields

There are many people who breed crayfish on the market, but some people produce high crayfish, while others produce low crayfish. There are reasons for this. Crayfish farming also requires certain techniques and methods. Therefore, it is very necessary to understand some techniques and methods before raising lobster.

Efficient crayfish culture technology in low-lying fields

First, pond conditions and preparation before stocking. Choose the low-lying area on the edge of the dike in Wei, the bottom material is sandy loam, covering an area of 0.5 hectare. The flow of the water body is relatively stable, and the effective water storage is 1.2 meters after heightening and strengthening the ridge of the pond. Separate the inlet and outlet.

Remove wild weeds in the pond before releasing shrimp seedlings, dry pond exposure for 2 weeks, and then sprinkle with massive lime with water, the dosage is 150 kg per 667 square meters, in order to kill wild fish and germs in the pond. After the removal of wild weeds, artificial transplanting excellent aquatic plants, such as water peanut, Elorella, goldfish algae and so on, these aquatic plants have strong regeneration ability and are very suitable for lobster life. The escape ability of lobster is no less than that of river crab, and it is very easy to escape under artificial breeding conditions when the living environment is bad. Take calcium plastic board on the ridge, bury it with plastic stripe cloth in the middle of the ridge, fasten the inlet and outlet with a tight mesh to prevent escape, and check the escape prevention facilities regularly at the same time. One week before the shrimp fry is released, the manure and water are used in the same way as the manure and water before the fry goes down to the pond, so that there is plenty of bait in the pond. The first injection of new water should not be too deep, about 50 cm is appropriate, with the growth of shrimp seedlings, you can gradually add water. Second, seedling stocking. Purchase fresh shrimp fry from the market and the surrounding Tangkou in March every year. 10 kg of 2.5 cm shrimp seedlings were released on March 5, 15 kg of 3 cm shrimp seedlings on March 10, 222 kg of 3.5 cm shrimp seedlings on March 15, and 365 kg of more than 4 cm shrimp seedlings on March 18. As the shrimp seedlings were transported nearby, the dead and soft-shell shrimp seedlings were removed before going into the pond, and then disinfected with 40 g / L salt water for 10 minutes to kill surface bacteria and parasites. Third, feeding and management. The bait was started in the middle of March, and at the initial stage, it was mainly fed with fresh bean dregs and rice bran. From May to September, feed chilled fish, pumpkin, green vegetable leaves and so on. Ensure that the lobster is well fed, and the feeding amount is 5-10% of the body weight, depending on the lobster eating and activities. Chilled fish should be chopped into small pieces and pumpkins cut into shreds to facilitate crayfish intake. The residual bait should be removed in time to prevent the deterioration of water quality.

The water quality of lobster culture should be "fat, live, tender and cool". The early stage should be fat, the water color is mainly yellowish green and tea brown, and the transparency is about 30 cm. If the transparency is too small, the amount of water should be increased and the water should be changed every semimonthly. The transparency is maintained at about 40 centimeters in summer. The water level is maintained at 1.2 meters, the coverage rate of aquatic plants is 50%, and the pH value is controlled at 7.5-8. Disease prevention and control should give priority to prevention, and water should be changed regularly. In the whole culture process, quicklime was sprinkled twice and garlic was fed 6 times in summer, no obvious disease was found. During the breeding period, keep patrolling the pond every day to observe the lobster's feeding, activity, growth, intake, drainage and escape prevention facilities, and deal with the problems in time. The lobster has a very strong ability to dig holes, so it must be inspected on the outside of the pool ridge. Fourth, effect discussion. Commercial shrimp has been caught since late May, with specifications ranging from 20 to 25 per kilogram. Catch large and stay small, the fishing method is ground cage fishing, shrimp is taken every 4-8 hours to prevent lobsters from dying or breaking fishing tools in the ground cage. A total of 1830 kg was caught with specifications of 20-25 pieces / kg, the average price was 16 yuan / kg, the total output value was 29280 yuan, the total cost was 19530 yuan, and the profit was 9750 yuan. Lobster has a strong ability to adapt to life, and its yield is very unstable in the wild. Under the condition of artificial high-density culture, lobster becomes very fragile. We must pay attention to three points: ⑴ insists on patrolling ponds, lobster has strong ability of digging holes, strong ability of climbing on land, and anti-escape is the key; ⑵ lobsters grow fast, kill large and small, and should be raised in different specifications when cultured; ⑶ catches large and stays small, can improve the efficiency of breeding.

Crayfish culture cycle

Depending on the water temperature, the breeding period of lobster is somewhat different from that of ordinary animals. generally, the breeding period of lobster is mostly in spring, while the breeding period of lobster is mostly in autumn, and the seedlings can only grow from winter to summer, because the water temperature is low in winter. Seedlings grow slowly, even not long. If the water temperature is right, nutritious lobster can grow in only 50-70 days.

It also depends on the situation. if the wild ones reproduce very fast, release the shrimp in March-April and directly let the prawns reproduce freely. They can be caught around June, and can be caught every day in the future.

Artificially bred varieties grow faster, and the growth cycle of "Huafeng 9" in Wuhan Huayufeng Aquatic Farm can grow to 50-70 grams in 60-90 days.

How to clean the crayfish

1. Put the crayfish directly into the water mixed with vinegar and salt and soak for 30 minutes to force the crayfish to spit out the dirt on the cheeks. Use a small brush to scrub the crayfish one by one.

2. Peel off the head shell of the crayfish and we can see the stomach sac that acts as a digestive organ. It is very dirty. This must be removed. There is something similar to intestines in the belly of crayfish, which must be removed. It can be easily done by squeezing the wings in the middle of the crayfish tail with your hands.

3. There is a delicious' yellow'in the crayfish's skull, so when you wash it, you can use scissors to cut it at an angle of about 45 degrees from the top of the head, so you can take out the stomach sac while keeping the 'yellow'. Finally, remember to rinse carefully with thin water.

4. boil the lobster in boiling water, and the white dirty foam will come out slowly. Skim off the foam with a spoon so that the crayfish will be washed clean.

Crayfish culture cost

Generally speaking, the cost of raising lobster is only 2 yuan per kilogram. If domesticated, the average cost per kilogram will reach 3 yuan. Lobsters are sold according to specifications, and about 75 grams are sold for 3 yuan, 50 grams for about 1.5 yuan, 40 grams for about 1 yuan, and less than 40 grams for continuous cultivation. "on average, one sold for 1.6 yuan.

The seedling density depends on the seedling specification, shrimp pond area, pond water depth, pond bottom condition, water exchange condition, bait type, feeding method, production skill and management level, and should be determined with reference to the yield requirements and specifications put forward by shrimp farmers. The amount of seedlings can be calculated with reference to the following formula:

Seedling release = (planned seedling yield (kg) × Mantissa required to cultivate 1 kg) / estimated survival rate

In the formula: the planned yield per mu can be calculated with reference to the output of neighboring areas over the years; the Mantissa of 1 kilogram of shrimp can be calculated as 30-50 (body length 12-15 cm); the survival rate is 50%-70%, and the intermediate cultured shrimp fry is 85%.

In general, under the conditions of good quality of shrimp seedlings, superior water exchange conditions, guaranteed bait and high level of feeding and management, the number of seedlings per mu can be about 20 000 (not more than 25000). After intermediate cultivation of shrimp seedlings (about 2.5 cm in body length), the amount of seedlings per mu was controlled between 8000 and 12000.

At present, the market for crayfish is increasingly tight, and more and more people like to eat lobster, so there are many lobster farmers in the market, but novice lobster farmers should learn from the successful ones and share their successful experiences.