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1. It is necessary to create a good pond condition. (1) It is required that the water source is sufficient, the water quality is fresh, and there is no pollution, which conforms to the national fishery water standard. Dissolved oxygen is greater than 5mg/l, the bottom of the tank dissolved oxygen should be greater than 3mg/l, ph is 7.5-8. The area is 2-5 acres, the water depth is 1.2-1.8 meters; the bottom of the pool is flat, the slope is 1:2-2.5; each pond needs to be equipped with 1-2 sets of 1-1.5 kilowatts of aerators; inlet 80 ports Bags are filtered to prevent wild fish and fertilized eggs from entering the shrimp pond.
(2) Disinfection in clear ponds: 7-10 days before stocking, the shrimps should be disinfected with 75-100 kg/ha quicklime to kill pathogens and predators.
(3) Add water and fertilize. After 2-3 days of lime disinfection, add 50-60 cm of water and apply 150-200 kg/mu of fermented organic fertilizer to cultivate natural food organisms.
(4) Set up aquatic plants and concealed objects. After the shrimp ponds were added with water, the grasses were planted immediately. The plants were mainly black-leaf hyphorons, supplemented with a small amount of agro-grasses, with a spacing of 1-2 meters. The agro-grass was planted in deep water and planted in shallow water, covering about 30% of the water surface. The role of aquatic plants: for green shrimp habitat, clam shells and shelter; photosynthesis can increase dissolved oxygen in water; purify water quality and prevent water quality deterioration. Practices in production from all over the country have shown that ponds with more aquatic plants have late eggs and large specifications. In addition, some tea twigs, bamboo shoots, etc. can be placed in Shallow Pond Shallow Water. Conditions can also be laid mesh, the implementation of three-dimensional breeding, to increase the habitat of fresh shrimp, and further improve the utilization of water, can effectively increase production and increase the size of commercial shrimp.
2, buy high-quality shrimp seedlings and reasonable stocking (1) should be to the original shrimp farm (good) species to buy shrimp, avoid avoiding cost for years of self-breeding self-breeding. Choose shrimps of different habitats or original (good) species to hold eggs and breed eggs. As long as the density of shrimps in nursery ponds is moderate, it is generally controlled within 800,000 to 1 million tails/mu, and the size of seedlings produced is relatively neat. The breeding shrimp was selected as the parent to breed the shrimp seedlings. Due to inbreeding, the harmful genes of the shrimp continued to be homozygous, making the seed quality worse and worse, sexual maturity getting earlier and earlier, and the commodity shrimp specifications getting smaller and smaller.
(2) Prolong the release time. The shrimp larvae that were stocked in May and June were mostly sexually mature after being fed for two or three months. In August and September, a large number of sub-generation shrimps will be produced. If the stocking time is postponed until mid-to-late July, the sudden change in the living environment of the shrimp will enable the autumn crop phenomenon to be controlled to some extent.
(3) Adjust the density of stocking and implement arresting and rearing. Sooner or later, sexual maturity of shrimp is closely related to stocking density. The greater the stocking density, the earlier the sexual maturity. The reasonable density can not only guarantee the high yield of the shrimp, but also delay the growth of the vast majority of the shrimp and achieve the larger specifications. The specific stocking densities should be determined according to the farming pattern: the ponds should raise penaeid shrimps, and 6-80,000 shrimps of 1.5-2.0 cm per acre should be put in place; with the conventional fish polyculture, 1.5-2.0 thousand seedlings per acre can be released. . Spring shrimp species, density should not be too large, the general stocking specifications per acre 1200-1600 only / kg of shrimp species 8-10 kg, to ensure that the development of the market from May to June.
In addition, measures should be taken after September to catch fish, to catch fish, and to keep small, and shrimps that meet the specifications of the fish should be caught and listed in time to reduce the amount of shrimp in the pond and promote the growth of the shrimp.
3. Reasonable feeding of feedstuffs for freshwater prawns requires high-quality, fresh-sized pellets. The prawns require a crude protein content of 35-40% in the larval period and a shrimp feed in the middle and later stages (above 4cm). The crude protein content reaches 30-32. %. Feeding follows the "Four Sets" principle, which should be adjusted flexibly according to weather, water temperature, water quality, and feeding conditions.
4. Strengthen water quality management and maintain good water quality. Green shrimp are not tolerant to hypoxia, and their oxygen consumption and suffocation points are higher than those of the main freshwater cultured fish. In the absence of oxygen in the fish pond, the shrimp always dies and first dies before the fish. Therefore, the regulation of water quality is the key to the success or failure of the cultivation of shrimp and the yield. The shrimp water quality must meet the requirements of “fat, live, tender, and coolâ€. Its main measures are as follows:
(1) Mechanical oxygenation. Due to the relatively large number and high density of shrimps, it is necessary to ensure that the shrimp pools have sufficient dissolved oxygen. 7,8,9 months from 16:00 in the evening to 7:00 in the morning the next morning should be more aerobics machine, hot days or rainy days, during the day should be properly boot oxygen. In particular, when the autumn young shrimps are stocked, they are in the high-temperature season. The net catching and seedlings are usually carried out at low temperatures in the morning, but this time is the time for the lack of oxygen in the pond water. If the shrimp ponds are not used in advance, oxygenation measures are taken. , It is easy to cause hypoxic death of shrimp seedlings.
(2) Frequently add new water or apply microbial preparations. Frequent injection of new water is the most effective measure to improve shrimp water environment and maintain good water quality. In places with convenient water sources and good water quality, adding new water can increase dissolved oxygen, nutrients and trace elements, dilute the concentration of metabolites and toxic substances, and prevent pool water aging. In the absence of water or water inconvenient shrimp ponds, photosynthetic bacteria, EM original dew, Bacillus and other beneficial microbial preparations should be adopted to improve and regulate water quality.
(3) Appropriate top-dressing cultivation of plankton at the right time, keeping the color of the water ideal for yellow-green or brown, with a transparency of 25-30 cm. Dressing fertilizers generally use organic fertilizers such as decomposed organic fertilizers and fertilizers such as urea and superphosphate.
(4) Sprinkle quicklime regularly, generally with 15 g/m3 lime water Quanchiposa every 15-20 days, while regulating ph to play the role of bactericidal calcium.
5. Set the fish species at the right time and control the over-breeding of the green shrimp. During the cultivation of the shrimp, in order to maintain a reasonable breeding density in the shrimp pond and increase the commodity rate of the green shrimp, when the juvenile shrimp is propagated to a certain amount, it may be appropriate. Nesting some species of fish not only maintains the biological diversity of the water, but also controls the overproduction of green shrimp in the pond. Fish breeding time is controlled at the end of August and early September. The main breeding stocks are the whitebait, the Xiangyun, the squid, and the stingray, and the number should not be too high. Usually, about 100 tails per mu are placed. The fishes were allowed to ingest a large amount of plankton in the pool and the larvae before the metamorphosis of the shrimp, thereby controlling the number of the young shrimps.
6. Several methods to control the precociousness and density of penaeid shrimp (1) Improve the stocking mode: Many breeders mainly rely on stocking and holding eggs, and carry out self-cultivation, self-breeding and self-support. This model is a broad-based method of raising shrimp. Although seedlings have low costs and are convenient and practical, it is difficult to control the density. The specifications of listed shrimps are uneven and the yield and benefit are not high. Therefore, in order to increase output and efficiency, it is necessary to adopt technical measures such as reforming extensive culture to intensive breeding, relocating holding eggs to raise high-quality shrimp, and raising one-pot shrimp to two shrimps.
(2) When the juvenile larvae appear in the shrimp pond in early September, the water volume may be increased or the whole pool may be splashed with 20 kg/ha of calcine sap, and the ph value may be rapidly increased to make the prawns and pupae not yet metamorphosed. The larvae die because they cannot tolerate mutations in water quality factors.
7. Strengthen prevention and control of shrimp disease Adhere to the principle of “prevention and health managementâ€. Prevention work In addition to clear pond disinfection, selection of high-quality shrimp seedlings, reasonable stocking, and feeding, regular application of quicklime, dibromohydantoin, super iodine quaternary ammonium salt for water disinfection. Green shrimp are far less common diseases such as white shrimp, river crab, and fish. The main diseases are black shank disease, red body disease, soft shell disease, and so on. They should be treated according to different diseases.
A Brief Introduction to the New Technology of High-yield Breeding of Green Pond
Green shrimp, the scientific name of Japanese Macrobrachium, is a traditional breed in China. Because of its delicious taste and rich nutrition, it is highly favored by the market and consumers. Compared with Macrobrachium rosenbergii, Penaeus vannamei, and other seed species, the price is stable, and the risk of breeding is small, so the shrimp aquaculture industry is relatively stable. However, with the continuous expansion of the scale of shrimp farming and the increasing intensification of the degree, problems have also arisen. The most prominent problem at present is the severe breeding of penaeid shrimp, degraded germplasm, and advanced sexual maturity. Problems: First, precocious shrimps grow slowly, nutrition accumulates in gonadal development, the size of commodity shrimp is too small, and the market price is low, directly affecting economic efficiency; second, precocious shrimps multiply their prawn and make them green. Shrimp density increased rapidly, and shrimps and shrimps competed for food, competed for oxygen, and competed for space. As a result, shrimps did not go through the specifications and commodity prices drastically decreased, which in turn affected the aquaculture production, thus constraining the healthy development of the shrimp aquaculture industry. . How to increase the aquaculture production, product specifications and economic benefits of shrimp is a common concern for every shrimp farmer. Therefore, we must explore new breeding modes and find new breeding techniques to achieve high quality, high yield, and high efficiency. Based on past experience in the past, combined with the actual production, we will focus on introducing the new technologies for the healthy, high-yield culture of pond shrimp, for your reference.