Six levels of crayfish culture in ponds can improve the efficiency.

When it comes to crayfish, maybe many people are drooling, and people who know it should be very clear that although there are many ways to make small dragons on the market, most of them are mainly spicy crayfish in the form of midnight snacks, so the demand for crayfish in the market is very large.

Six levels of crayfish culture in ponds can improve the efficiency.

1. Release good seedlings and close them.

The stocked shrimp seedlings should be of neat specifications, strong physique, strong vitality, intact appendages, no injury or disease. The specification of stocking shrimp fry should reach 0.8cm to 1.0cm, the specification of shrimp species should be more than 3cm, the stocking density should be reasonable, and the stocking standard of the same pond mouth should be the same. The method of stocking shrimp seedlings is to first put the shrimp seedlings into a plastic basin, slowly add a small amount of pool water until the water temperature in the basin is similar to that of the pool water, and add salt at the concentration of 3%-4%, let the shrimp seedlings be immersed and sterilized for 3-5 minutes, and then slowly put into the pool along the edge of the pool.

Winter stocking should be carried out in sunny morning, and summer and autumn stocking should be conducted in sunny morning or cloudy and rainy day. Prawns should be soaked in 3%-5% salt water for 5 minutes for 10 minutes to kill parasites and pathogenic bacteria. The shrimp species purchased from other places have been out of water for a long time after long-distance transportation. when stocking, put the shrimp species into the pond water for 1 minute, then take them out and leave them on the edge of the pool for 2-3 minutes, soak and take out 2-2-3 times repeatedly, let the shrimp species absorb enough water on the body surface and Gill cavity, and then slowly put the shrimp species into the pond, which can improve the stocking survival rate. In order to make full use of the culture water space, some species of silver carp (bighead carp and silver carp) can be stocked with 100g ∕, 50 and 100 respectively. Reasonable matching of some silver carp can not only increase the yield per unit area and improve the economic benefits of culture, but also make full use of the bait resources in the pond and improve the water quality of the pond.

2. Put the good feed on and off.

Crayfish are omnivorous, especially like to eat animal bait, and naturally greedy, large food intake. The feed should be nutritious and moderate. Insufficient feeding will affect growth and even kill each other; if the feeding is too large, it will cause feed waste and pollute water quality; if the feed is not nutritious, it will cause malnutrition and affect growth. In high-density culture, crayfish are mainly fed with compound feed. When shrimp seedlings and shrimp species first enter the pond, a large number of rotifers, cladocera, copepods and aquatic insect larvae can be fed by fertilizing and topdressing. The protein content of formula feed for young shrimp should be more than 30%, and that for adult shrimp should be more than 26%. It should be fed twice a day, once in the morning and once in the evening, before sunrise in the morning and after sunset in the evening, mainly in the evening, accounting for 70% of the daily feed.

The daily feeding amount is mainly determined by the total weight of crayfish in the pond. From March to April and after October, the daily feeding amount is 1%, 3% and 3%. From May to October is the normal growing season of crayfish, and the daily feeding amount is about 5%. It should be fed more when the weather is fine, and less when it is hot and muggy, continuous rainy weather or when the water quality is too strong. A large number of shrimps are fed less when molting and more after molting. Feeding should adhere to the "four fixed" principle, that is, positioning, quantitative, timing, quality. The amount of feeding with rest should be flexibly controlled according to the weather, water temperature, water color and the growth of crayfish, and it is appropriate to eat, finish and leave no residual bait.

3. Manage the molting period well. The molting period is a critical moment for the growth of crayfish, and it is particularly important to do a good job in the management during the molting period.

The first is to maintain good water quality. Often add fresh water to keep the water fresh and free from pollution, and let the crayfish molt in a good water environment, which can shorten the molting time and is beneficial to the development and growth of crayfish.

The second is to ensure feed nutrition. Crayfish lose a lot of calcium, phosphorus, iron and so on after each molting. Therefore, the formula feed should contain indispensable ingredients such as calcium, phosphorus and iron, and the animal and plant feed should be matched reasonably.

The third is to plant and maintain aquatic plants. Aquatic plants such as verticillium verticillata, Eloe verticillata and bitter grass are planted in culture ponds, with a coverage rate of more than 60%. Crayfish like to molt in shallow water or grass. After molting, the soft shrimp will immediately hide in the grass to avoid the same kind or enemy food.

The fourth is to destroy the enemy and harmful creatures. The main enemies of crayfish are water rats, frogs, waterbirds and some fierce carnivorous fish. These animals can prey on crayfish and do more harm to the soft crayfish after molting, so timely measures should be taken to eliminate them. For carnivorous fish, in the process of entering the water, they can be filtered through a dense net to keep them away from the mouth of the culture pond. Rat traps and cages can be used to kill rodents; for birds, some colored strips and scarecrows can be set up by the pool to drive away. The most effective way for frogs is to catch them manually at night.

The fifth is to give bait. During the molting period of crayfish, we should use as little medicine as possible, without chemical preparation, and add photosynthetic bacteria, immune polysaccharides, multi-vitamins, shellfish, calcium dihydrogen phosphate and so on to feed, which can enhance the physique of crayfish and reduce the occurrence of shrimp disease. promote the healthy growth of crayfish.

4. Control the water quality well.

Maintaining good water quality is beneficial to the healthy growth of crayfish. Add fresh water once every 7-15 days, adding 20 cm of water each time to keep the water fresh and clean; disinfect the water with quicklime every 10-15 days and adjust the pH value to 7.5-8.5. After adding hydrated slurry, quicklime is sprinkled throughout the pond while it is hot, with a dosage of 667 square meters of 10 kg of water surface to keep the water quality weakly alkaline; use microecological agents such as photosynthetic bacteria, EM bacteria or sediment modifiers once a month to reduce harmful substances such as ammonia nitrogen, nitrite and hydrogen sulfide in the pond, improve water quality and bottom quality, and control the transparency of pond water to 35 cm to 40 cm.

Usually, the oxygen enrichment equipment should be turned on frequently to keep the dissolved oxygen in the pool water above 5 mg / L. Wei Ailiang, a demonstration household of crayfish farming in Jinhu County, Jiangsu Province, installed a dissolved oxygen controller on the oxygen enrichment equipment, which automatically controls the automatic start and stop of the oxygen enrichment equipment according to the upper and lower limits of the dissolved oxygen demand of the crayfish, so that the dissolved oxygen in the shrimp pond can always be kept in the best set state, and the crayfish can grow well in a comfortable and happy environment. The author thinks that this technology is worth popularizing and applying widely. 5. Keep a good quality of crayfish.

Strictly enforce the production standards of pollution-free aquatic products, strictly prohibit the use of prohibited drugs and inputs, strengthen feeding management, and improve the quality, quality and efficiency of crayfish culture. 6. Timely fishing should be done well.

After raising crayfish for about 2 months, the size of crayfish can reach more than 50 grams. At this time, we can start fishing and put large-sized crayfish on the market, reduce the density of crayfish in the pond and promote the rapid growth of small-sized crayfish. Fishing tools include shrimp cages, ground cages and so on.

Breeding and management of crayfish in paddy field

I. Feed feeding

Shrimp culture in rice fields should try to achieve timing, positioning, quantitative, qualitative feeding. Lobster eating habits are miscellaneous, meat (small fish, snail meat, river meat, fish, earthworms, animal offal, silkworm pupa), essence (sugar cakes, corn, wheat, barley flour), green (there are all kinds of aquatic grasses, vegetable scraps, etc.) feed. The daily dose is generally 4% to 6% of the body weight of shrimp. In the early stage, they were fed twice a day, once in the morning and once in the afternoon, and once at about 18:00 in the later stage.

II. Water and fertilizer management

After lobster stocking, field ditch management is a very important link. The water depth of the paddy field is maintained at about 20cm, and the water injection is generally carried out at 10lv 00Mel 11RU 00, keeping the water temperature of the diversion water close to that of the paddy field.

In the process of rice field management, the water level should also be regulated according to the requirements of rice drying and pest control. In the middle stage of rice growth, the field should be exposed properly, so as to increase light, root activity, sterilization and temperature. At ordinary times, we should also do a good job in flood control, drainage and escape prevention, and timely check whether the inlet and drainage and shrimp interception equipment are in good condition after a rainstorm to prevent shrimp escape.

III. Prevention and control of diseases and natural enemies

Adhere to the principle of giving priority to prevention and combining prevention with prevention. In the process of rice growth, it is necessary to spray pesticides to control pests, and fresh water should be replaced after spraying pesticides, so as to provide a necessary ecological environment for the growth of rice and lobster. High-efficiency and low-toxic pesticides were mainly used for rice disease control, spraying method was adopted to make the medicine fall on the leaf surface, and the suitable application time was 8-00-00-100-100 on a windless sunny day. If the enemy is found, it should be eliminated in time, and at the same time, a secret net should be placed at the outlet to prevent the enemy from entering.

Advantages of raising crayfish in rice fields

First, increase production and income;

Second, lobster can eat wild weeds and aquatic organisms in the field, but not rice seedlings, but also eliminate harmful larvae, including mosquitoes, and play a role in weeding and weeding.

Third, the swimming and foraging of fish and shrimp help to loosen the soil, live water and ventilation in the paddy field, increase the dissolved oxygen in the field water, and discharge a large amount of feces through metabolism, which has the effect of increasing fertilizer.

Culture and stocking techniques of crayfish in winter

1. Stocking should be carried out on sunny or rainy days to avoid sun exposure.

2. Purchase crayfish. If it takes a long time to leave the water, it should be treated slightly before stocking. Soak the shrimp in the pond water for 1-2 minutes, lift and shelve for 2-3 minutes, soak for 1-2 minutes, repeat 2-3 times, and let the shrimp absorb enough water before stocking, which can improve the survival rate.

3. Stocking density. Stocking 150kg-250kg per mu, specification 16-20 per kilogram, stocking crayfish requires strong physique, uniform specifications, complete appendages, foot release at one time, avoid batch stocking, in order to reduce killing each other.

4. Silver carp and bighead carp can be stocked in the overwintering pond to regulate the water quality and improve the utilization rate of bait.

With more and more crayfish farmers, there are many new farming models. If we want to develop in the aquaculture industry, we must keep pace with the times and constantly develop new technologies and methods in order to achieve better results.