Freshwater shrimp culture technology

With the continuous improvement of living standards in our country, the demand market of shrimp in our country is increasing. The technology of freshwater shrimp culture is more popular in the current shrimp industry, and it is also adopted by many shrimp farmers. With the continuous updating and development of the technology of China's aquaculture industry, breeders should constantly innovate and improve the existing technology in order to achieve certain results.

Freshwater shrimp culture technology

First, the habit of raising shrimp

Green prawns live widely in lakes and ditches and rivers, and most like to live in shallow waters with many aquatic plants. They are omnivorous animals, larvae are mainly plankton, and adult shrimp feed mainly on decaying stems and leaves of aquatic plants. Prawns usually mate and lay eggs from July to September, spawning 800 to 1200 eggs each time. As the fertilized eggs are well protected by the mother, the natural hatching rate is more than 92%. After peeling for 3 or 4 times, the larva becomes young shrimp. It takes only 2 to 3 months for young shrimp to mature and lay eggs. The fecundity of green shrimp is strong, and the female shrimp can ovulate again soon after ovulation and hatching.

Second, the culture of green shrimp

There are two methods for shrimp culture: one is to directly breed green prawns, 500,800 females and 300,500 males per mu, which should be released at the end of April and the beginning of May. The second is to release artificially cultivated young shrimp: first, use a pond of about one mu as a breeding pond. before the Beginning of Summer, capture 10-12.5kg of parent shrimp with eggs from other rivers, from which individuals with strong and large number of eggs are put into the pond, and put water grass or poplar roots in the pond. During the period of labor, a small bucket of soybean milk (about 1 kg of soybeans) is fed every morning, followed by a bucket of vegetable cake or sugar lees (about 5 kg of dry products). Twenty days after hatching, 250 young prawns can be bred. When raising green shrimp artificially, the yield per mu can reach 15,25kg, and the high yield can reach nbsp40~50 kg.

III. Bait supply

The feeding habits of green shrimp are mixed in artificial feeding, all kinds of artificial feed can be fed, such as snail, silkworm pupa, fly maggot, fish meal and so on. Plant feed includes bean cake, rice bran, wheat bran distiller's grains and so on. Bait at 5 pm is appropriate, can be evenly scattered around the shrimp pond, the appropriate quantity, so as not to kill each other because of hunger.

IV. Artificial culture ponds

Shrimp ponds should be built for artificial breeding of green shrimp. Shrimp ponds can be used in general fish ponds, an area of 2 mu, water depth of 1.2 to 1.5 meters, flat sand bottom silt should not be too much. Shrimp ponds should be close to water sources to facilitate drainage and irrigation. The swimming ability of green shrimp is poor, so some submerged plants such as shrimp algae should be propagated in shrimp ponds for shrimp habitat, but the area should not exceed 25% of the water area, and tree branches can also be put into the shrimp to prevent the loss of shrimp seedlings. Before stocking, tea meal, Croton, bleach, fish rattan essence or other drugs are usually used to kill harmful fish and large aquatic insects in the pond to avoid enemy encroachment. Shrimp ponds should strengthen the usual pond patrol management to prevent pond ridge collapse, leakage or water birds, water rats prey on green shrimp. Once a large number of young shrimp are found jumping, swimming on the water surface, or climbing on the edge of the pond, it means that the dissolved oxygen of Lu in the pond is on the low side, and the metabolite is too high, which will cause a large number of prawns to die, so it is necessary to change water and increase oxygen immediately.

Matters needing attention in lobster culture

1. Strictly clean the pond and disinfect it. The shrimp pond should be exposed to the sun for 15-20 days until the surface of the pond is dry and cracked. Two weeks before planting, a small amount of water was injected, the bottom of the pond was evenly scattered after melting with 100kg quicklime per mu, and the bottom was raked once in the silt by artificial method, and the whole bottom was covered with water every few days, sprinkled in the whole pool with 2kg chlorine dioxide and soaked 50kg rapeseed cake per mu, 2-3 days later, the disinfection water was released, the pool was sunburned for 3-5 days, and then filtered and injected with new water.

2. Improve the pond conditions of lobster culture. The environment, area, water depth, water quality index and other basic conditions of the culture pond should meet the GB/T18407.4 standard. The water source does not have any pollution, the water quantity is sufficient, the water quality conforms to the NY5051 standard, the intake and drainage is convenient. The shrimp pond is rectangular, broad and sunny, with a flat bottom, sandy soil or loam. During the shrimp growth period, the PH value, ammonia nitrogen content, nitrite content and dissolved oxygen of shrimp pond water quality can not exceed the standard.

3. Choose and buy high-quality shrimp seedlings. Before selecting and purchasing shrimp seedlings, it is necessary to investigate the production license, credibility and parent shrimp sources of the seedling farm, the cultivation of shrimp seedlings sold over the years, the use of drugs during the breeding period, and so on. Shrimp seedlings should be tested by the inspection and quarantine department before leaving the scene, and do not enter the seedlings from the epidemic area to prevent pathogens from entering.

4. Strengthen the management of water quality. Appropriate water supplement and fertilization during lobster culture, maintain a certain degree of fertility of water quality, adjust the composition of algae in the water, make green algae or diatoms become the dominant population, and open to a certain number. The indexes such as dissolved oxygen, ammonia nitrogen, nitrite and PH value are measured every 7-10 days. If a certain index is uncomfortable, relevant measures should be taken in time. After one month of stocking, the shrimp seedlings should use the microbial preparation once every 10-15 days to remove the harmful substances in the pond; after two months of culture, attention should be paid to improving the substrate, such as using the substrate modifier, turning on the aerator to increase oxygen, and so on.

5. Choose and feed. Select large-scale, stable quality, palatable nutritious feed varieties to meet the nutritional needs of each growth stage. Enhance the immune function of shrimp, resist the invasion of pathogens and environmental mutation. Feeding should insist on eating more and less, and assist to feed live bait 1-2 times a week (small miscellaneous fish, snails, clams, clams, etc.). And often periodically add immune polysaccharides, shrimp multi-dimensional, etc., to enhance disease resistance and anti-allergy ability.

6. Scientific prevention and treatment of diseases. The disease prevention and control of lobster culture should be transformed into many aspects of prevention, management and health care. During the culture period, we should adhere to the morning and evening pond inspection, observe the occurrence of shrimp disease, but also understand the occurrence of shrimp disease near and around the culture area, and take relevant measures in time to find problems. During the growth period, every 15-20 days, use bromochlorohydantoin spray disinfection in the whole pool, can also be disinfected with quicklime, but the dosage and frequency should not be too much.

Species of freshwater lobster

1. Macrobrachium nipponense. Also known as green shrimp, belonging to soft nail subclass, Decapoda, Parade suborder, Brachionidae, feeding habits, rapid growth, high reproductive ability, strong disease resistance and other characteristics.

2. Macrobrachium rosenbergii. Macrobrachium rosenbergii has different habitat habits with different growth stages. The larvae must survive in brackish fresh water with salinity of 8 ‰-22 ‰. Young and adult shrimp live in fresh water. The survival temperature is 15-35 ℃, and the suitable growth temperature is 22-32 ℃. Adult shrimp has no limit to salinity, so it can live in both fresh water and brackish water with low salinity. And like to live in the lower reaches of the rivers affected by the tides and the lakes, canals, paddy fields and other waters connected with them.

3. Protocrab shrimp. The original crab shrimp is shaped like a shrimp and has a hard carapace. The adult is about 5. 6-11.9cm, dark red, the carapace is nearly black, and there is an oblique stripe on the back of the abdomen. The young shrimp are uniformly gray and sometimes have black ripples. Crabs, long and narrow. The middle part of the carapace is not separated by reticular voids, and there are obvious particles on the carapace. It can grow in salinity from 3 ‰ to 9 ‰ and can withstand high temperature of 40 ℃ and low temperature of-15 ℃. Strong fecundity.

4. Red crab shrimp. Also known as Australian lobster, freshwater lobster, crayfish. The shrimp can live in rivers, lakes and ponds, benthic, crawling, and can survive in brackish water. Omnivorous, eating organic detritus, aquatic plants, aquatic insects, small benthos, fermented cow dung and artificial formula feed. The optimum water temperature is 22-32 ℃. The limit water temperature is 4 ℃ and 37 ℃. When the water quality deteriorates, it can climb out of the water and save itself.

Construction of lobster culture base

1. The location of the lobster culture base must fully consider the surrounding environment, such as whether the water source is rich, the source of bait, transportation and the convenience of power supply, etc., among which the investigation of water quality is very important. The PH value of the water must be controlled at about 6-8.

2. The disinfection work of the lobster culture base can generally be carried out through quicklime and bleach powder. It is only necessary to break the quicklime and sprinkle it evenly into the pool water, and then stir the bottom of the pool with an iron rake the next day, so that lime and silt can be fully mixed. Of course, there are many specific disinfection methods, and farmers can choose by themselves.

3. The construction of lobster culture base needs professional technical personnel, and professional technical personnel are very important for lobster culture bases. for example, breeding pond preparation, parent shrimp selection, parent shrimp delivery, parent shrimp cultivation, water quality management, fertilization and incubation, shrimp seedling cultivation and so on all need scientific and reasonable technology to ensure the healthy growth of lobster.

Lobster culture, whether from the construction of the base or lobster culture technology, there are certain technologies and skills, although China's aquaculture industry is developing relatively rapidly, it is still necessary to constantly develop new technology and innovation in order to make the aquaculture industry develop better and broader.