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I. Preparation for breeding ponds
1. Breed pond conditions. The area of ​​the breeding pond for shrimp is 0.2 hectares - 0.3 hectares, with a depth of 1.0m - 1.2m, and a pond slope ratio of 2.5 - 3.0:1. Set a shrimp pond of 20m2 - 30m2 at the outlet. Meter. Breeding ponds should be selected from areas with sufficient water, fresh water, no pollution, and convenient drainage and irrigation.
2. Breeding pond clearing. One month before breeding, shrimp ponds were trimmed, reconstructed, and exposed in dry ponds. During the first 15 days of feeding eggs and broodstock, the ponds were first filled with water about 10 cm, and the ponds were disinfected with quicklime at 200 kg/mu. Five days after clear ponds. - Start water in -7 days, the water level is about 80cm, and the water inlet and outlet are filtered with a double layer of 80 mesh - 100 mesh sieve to prevent wild fish, frog eggs and other predator organisms from entering the breeding pool.
Second, the food culture of food organisms The abundance of food organisms is the key factor in breeding the survival rate of young larvae. The rich food organisms provide the ideal open bait for the development of the larvae of the shrimp, and its nutritional value is more comprehensive than the artificial feed. And can reduce the pollution of the pond bottom, keep the water fresh, so, in the first 5 days - 7 days after the broodstock broodstock, breeding ponds should be applied after fermentation of organic fertilizer 300kg/mu - 500kg/mu.
Third, the selection and breeding of broodstock
1. The choice of broodstock. Green-crawling broodstock broodstock is generally caught in large water surfaces such as lakes, reservoirs, ditches, and ponds in mid-to late May. Select lively females with complete limbs, body lengths up to 5 cm, and mature or nearly mature female ovaries as broodstocks. Ovary volume covers almost the entire back, the front end reaches the base of the forehead, and the egg's color is green or orange (if The color of the egg is gray-brown and appears eye spots, indicating that the egg has hatched and is easily detached from the mother, which is inconvenient for transportation and operation). The amount of stock for broodstock brooding is 8kg/mu -10kg/mu.
2. The breeding of shrimp. Practice has proved that the cultivation of brooding broodstock and zoea larvae is better performed with a small area of ​​intensive cultivation. The specific method of operation is the use of a 0.5cm mesh, 1.2m high polyethylene net mesh, and the bottom of the mesh. Immersed in mud and compacted, enclose a corner of the pond, with an area of ​​50-60 square meters, and put aquatic weeds along the perimeter of the fence, such as water hyacinths, water peanuts and other fresh aquatic plants, occupying the surface of the water in the fence. 20% - 30%, brooding broodstock into the fence to cultivate. After the broodstock is released, check the development of the shrimp eggs every day. After the juvenile larvae are all detached from the mother, use lobster cages and other fishing tools to remove the prawn from the market. At this time, press 150kg/mu--200kg/mu in the cultivation pond. Apply fermented organic fertilizer and continue to cultivate the bait's food organisms.
The wavy larvae in the seine net are cultivated with cooked fish broth and egg yolk, and the broth and egg yolk are filtered and sifted through a 60 mesh-80 mesh sieve. Four times a day, 10,000 shrimp and 0.5 kg of larvae are used as fresh fish. Yolk 2 were fed. The larvae have been intensively cultivated for a week, and their body length has reached about 0.5cm. The segregation nets can be gently removed for seedling cultivation. The seedlings were changed to fish and egg yolk as soybean milk in the early stage of cultivation. Each day, 3 kg of soybeans were used to grind the soybean milk into 3 batches of feed. After 15 days of cultivation, the length of the shrimp seedlings was about 1 cm, except for the daily soymilk feed. Increase the feeding rate of feeds and feeds. The feed volume accounts for about 5% of the body weight of the shrimps. It is fed twice a day. The amount of feed in the morning accounts for 20% of the total amount of feed, and the amount of feed in the afternoon accounts for 80%, along the pool. The shallow water area is fed at multiple points.
IV. Water Quality Management Water quality management of shrimp breeding is mainly to ensure that there are abundant food organisms, adequate dissolved oxygen, and appropriate pH. It takes 35 days to 40 days for larvae to grow to 1.5cm--2.0cm in length. During stock raising, the stocking density is high and the water quality is variable. Water quality, transparency, and the eating and feeding of shrimps should be used to adjust water quality in a timely manner. Scientific management of water quality.
1. Timely and appropriate fertilization and water injection and drainage. While controlling the pond water body fatness, it is also necessary to meet the growth needs of shrimp feeding on natural food organisms. Under normal circumstances, the shrimp nursery ponds are fertilized 2 times - 3 times a month, and 150 kg of organic fertilizer is applied each time. 200kg, and timely drainage according to the transparency of the pool water. The water depth of the pond during the post-cultivation period of the penaeid shrimp needs to be added between 1.0m and 1.2m to ensure that the penaeid shrimp grows in a good environment.
2. Adjust the pH of the water body. Green shrimp live in a slightly alkaline water body. With the input of artificial diet and organic fertilizer, the pH of the water body slowly decreases. The pH of the water body should be tested once a week. If the pH value is 5, the shrimp seedlings will be harvested. As long as 1.5cm--2.0cm, the stocking density of seedlings in the nursery pond has been quite large. In order to increase the emergence rate per unit area, the ponds should be divided in time. The fishing tools for the shrimp seedlings can be pulled out gently with the fry net, or According to the clustering characteristics of the shrimp seedlings, light trapping was carried out, and a triangular handprinting net made from 30 mesh to 40 mesh sieve was used to repeatedly capture at the poolside.
Shrimp Intensive Breeding and Seedling Technology
Green shrimp ponds, cages, paddy field scale breeding and large surface water propagation require a large number of high-quality shrimps. Therefore, artificial shrimp breeding under artificial control conditions is of great significance in production. Over the past few years, the author has conducted in-depth research on broodstock breeding, breeding, and seedling raising of young shrimps, simultaneously carried out demonstration and promotion of comparative scale, and achieved satisfactory results and economic benefits. The technology is summarized as follows.