Penaeus vannamei is a tropical shrimp with a suitable water temperature range of 15-32 °C. When the water temperature drops below 12 °C, it will not only fail to grow, but will also die. In the winter of winter, greenhouses can be used for breeding, so that three breedings can be produced in one year. In addition, the January and February of each year is the Spring Festival. The number of live shrimp is small and there are more people eating shrimp than usual. Therefore, the price of shrimp is particularly high. Doumen County of Guangdong Province has tried to breed white shrimps in South America on the basis of greenhouse cultivation of Macrobrachium rosenbergii in winter. The greenhouse can be covered with existing ponds, or it can be raised first and then raised. In the following, briefly introduce the status of greenhouse culture of Penaeus vannamei.
Cultivation of ponds and greenhouses
The culture of greenhouses in Penaeus vannamei can not be too large, because it is difficult to cover greenhouses too much, and the general culture area is 1-8 acres. Rectangular, 50-100 meters long, 10-50 meters wide and 1.3-1.8 meters deep. The greenhouse should not be built too high, too high wind blocking capacity, and waste of material, herringbone-shaped bottom edge and the pool edge close. The greenhouse was built into a herringbone scaffold, like a house. The width of the herringbone is exactly the width of the pond and the length is the length of the pool. Use fir or bamboo as a pillar, and use tight ropes between the two pillars so that the shed does not sway. The roof is covered with a heat-insulating film or woven fabric with 80% light transmittance. Pull a rope around the meter and weave it to the left and right so that the film can be pressed against the wind. A 1-kilowatt aerator is set for every 3 mu and an aerator is opened 24 hours a day for ventilation and oxygenation. If the weather is good, the temperature is high, there is the sun, and the insulation film can be opened at 2-5 pm for ventilation.
Preparation before putting shrimp seedlings
Before stocking Penaeus vannamei, the pond must be cleaned, cultured, and adjusted for salinity.
First, clear pond: new shrimp ponds should be advanced water 20-50 cm, soaked 2-3 times. For the old shrimp ponds, the pond must be dried first, then exposed to sunlight, and then the sludge and debris should be cleaned and finally disinfected. The advanced water is 20-30 cm, and it is splashed with 50 kg of bleaching powder or 100-150 kg of quick lime per 1 mu. If the pond is more acidic or has more humus, bleach can not be used. Only quicklime can be used. After 2-3 days after application, the pool water is drained and the water is then poured into 20-30 cm. Each 1 acre is soaked with tea cake and sprinkled in the whole pool. At this time, the pool water will not drain, because the tea cake has the role of fat pond.
Second, the bait organisms culture: After a thorough clearing pond disinfection, the inlet is equipped with 60 mesh funnel screen mesh, drain port installed on a 40 mesh flat net, and then into the water 60 cm, and then fertilize the cultured food organisms. Each mus of 1.5-2 kg of urea, 0.5-1 kg of phosphate fertilizer, dissolved in water and splashed in the whole pool. After 2-3 days, look at the color of the pool water for a top dressing. After a week of water quality training, the color of the pool water changed to dark brown or yellow-green, indicating that there is already a considerable amount of algae in the pool water. The transparency of the pool water is 30-40 cm.
Third, the treatment of salinity: because the Penaeus vannamei is a marine shrimp, is in the salinity of 25 ‰ -32 ‰ of the pool water cultured, the shrimp should be placed in a large pond breeding, the salt must be added to the pond , otherwise shrimp will not survive. There are three ways to add salt: 1 Add seawater. If the farm is not far from the sea, you can use the ship to transport the seawater. Before the release of seedlings, add 60-70 tons of salinity per 1 mu for 30‰-32. Sea water. Adjust the salinity of the pool water to 3‰-4‰; 2 Place underground salt water, pump underground salt water into the pond, add water quality improver, adjust the salinity of the pool water to 3‰-4‰, water depth 50- 60 cm; 3 Add salt, and use a colorful plastic cloth to surround a small pool in the pond. The area of ​​the small pond is 1/10 of that of the large pond. Fresh water and salt are added to the small pond so that the salinity reaches 9‰-10‰. The shrimp will be placed in a small pond first, and cultivated for about a week, and then the colored plastic cloth will be removed, and the individual larger shrimp will automatically enter the large pool.
Selection and stocking of shrimp
The shrimps that are placed in the pond must be selected. The excellent shrimps are flexible and bouncy, have a clean body surface, are uniform in size, have no deformity, and have strong swimming ability. The test method of swimming ability is to put the shrimp seedlings into a white water basin, and then turn the white bowl. If the shrimp seedlings are evenly distributed around the water basin without concentration, it indicates that the shrimp seedlings have strong swimming ability and are high quality shrimp seedlings. In addition, the shrimp seedlings are packed in bags and the shrimp seedlings will form explosive bounces in the bags. The specification of the shrimp seedling is 1.0 - 1.5 cm. In the shrimp and shrimp farms, the shrimp should be gradually reduced to a salinity of 5‰-8‰, so that the salinity of the shrimp farm is close to the salinity of the farm. The difference in salinity between the two parties cannot be greater than 5 ‰.
The density of larvae in the rearing ponds is 230,000 larvae per acre. The aquaculture pond has good environmental conditions and high management level. It can put 4-5 million shrimp seedlings per 1 mu. The water quality conditions of the shrimp ponds before the release of the seedlings should be tested in advance, and the seedlings should be planted in the morning or evening in good weather. When the seedlings are released, they must avoid cold weather.
Management during development
The management during the cultivation is mainly the management of water quality, feeding, and disease.
I. Water quality management: Management in the early stage of planting (from the first day to the 30th day) is mainly to gradually add water in order to improve water quality and increase the water level. If the water is too clear, you must add fertilizer or organic fertilizer to make the water forever. Stay yellow-green or dark brown. Open aerators throughout the day. Mid-term management (30 days to 60 days for seedlings) is carried out at 1-2 ppm bleaching for the whole tank every 10-15 days, and 5-10 ppm teacake can also be used for the whole tank disinfection. Change the water once every 2-3 days, each time the amount of water is about 1/3 of the total pool water. Post-management (day 60 to harvest) is basically the same as mid-term management.
Second, feeding: 1-15 days after planting, if the food is rich, do not feed, 15 days after the start feed, 2 times daily, feeding amount of shrimp body weight 8% -10 %, you can also feed fresh live feed every 2-3 days. In the middle stage, shrimp individuals gradually grow up and no longer feed the algae in the pool water. At this time, the amount of feed should be increased, and feeding should be done 4 times a day. The amount of feed should be about 5% of the shrimp body weight. In the later stage of management, it is fed 5-6 times a day, and the feeding amount is 3% -4% of the shrimp body weight.
III. Disease Prevention and Control: Disease prevention and control is the key to the culture of Penaeus vannamei, and prevention must be strengthened from beginning to end. Before and after the emergence of the seedlings, they must be given a single dose every 15 days in order to facilitate the regulation of water quality and prevent disease. Placing bleach and tea cakes has already been said. Check the water quality and shrimp body at any time during the shrimp raising process, and find that the problem should be dealt with promptly to prevent it from developing.
Harvesting Penaeus vannamei grows quickly in greenhouses, and can reach commercial specifications in more than 70 days, and can be harvested and marketed. During January-February, during the Spring Festival, the number of live shrimp in the winter is small, and there are many people who eat shrimp. The market can sell at a good price. Receiving shrimp can be caught in fixed shrimp cages, captured and kept small, fresh and marketed. You can also drain the pond water and harvest it once.
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