1 Pond conditions and preparation
1.1 Pond conditions and clearing requirements The pond is well-watered, convenient for drainage and irrigation, and has an area of ​​3-5 acres. The foot of the pond is flat and the slope ratio is 1:3 or more, and the effective water retention depth is 1.2-1.5m. Before the raising of post-seedling shrimp, dry ponds, clearing, exposing, digging trenches with a width of 1m and a depth of 0.5m and communicating with the drainage ditch shall be used as shrimp sewers; New water, water depth 0.6m.
1.2 Planting Concealed Plants Sponge vegetables are grown on pond slopes around the pond. Usually planted at the end of April, in mid-May, after the squid clearing pond is transplanted to the pond's 0.7m water level line, the planting distance is 0.1m. When the water level rises, the watercress grows to 2-4m when the pond grows well, occupying the whole area. One-fifth of the pond area, as a Macrobrachium rosenbergii inhabitation and clam shell environment.
1.3 Set up an intermediate cultivation pond at the leeward sunny position of the pond. Excavate a rectangular small pond with an area of ​​50m2. The depth of the pond is 0.8-1.2m. Take a bamboo scaffold and cover the membrane. The net is hung in the pond for the shrimp to inhabit. About 1 week before the stocking of shrimps (around April 15), 1kg of bleaching powder was used to disinfect the wild fish and germs. The water was infiltrated three days before the release of the seedlings (April 22) and heated (heat pump available) for heat preservation. When the water temperature is controlled above 22°C, Macrobrachium rosenbergii can be stocked.
2 Seed stocking
2.1 Macrobrachium roxburgii seedstocks are stocked on April 25th. Around 100,000 deseeded seedlings (2,000 pigs per square meter) are stocked in the middle cultivation pond. In the holding process, oxygen is pumped by an electromagnetic air pump. In mid-May, when the weather is clear and the pond water temperature is stable above 20° C., the insulation film is peeled off. After the water temperature in the cultivation pool is the same as the pond water temperature, the net is captured with a dip net. Count into the pond. Under normal circumstances, holding for 25 days or so, the survival rate of shrimps and shrimps is 60%-70%, the specification is 2-3cm, and 3-5 acres (1.0-2.0 thousand acres are stocked), 20 days after the shrimps enter the pond. On June 15th, 50 mu fish larvae were hatched or used to control plankton biomass in order to avoid excessive water quality and affect the feeding and growth of Macrobrachium rosenbergii.
2.2 Rearing of Macrobrachium species Macrobrachium rosenbergii was raised to September, and most of them have reached the market specification (60 tails/kg). They can be harvested in batches and listed until dry ponds in late October. They are stocked with catfish for 10 days after clearing the pond with lime. Species, specifications for each 0.15-0.2kg, 300 acres of stocking, accounting for about 50kg; fish ponds with malachite green and salt mixture disinfection.
3 Breeding management
3.1 Feeding
3.1.1 Shrimp aquaculture Freshly-frozen larvae first introduced into the greenhouse are mainly fed with tarts, twice a day, for 50g each time; 7 days later, they are fed with high protein diets such as surimi and soya bean milk, and the amount fed is 50% of the body weight of shrimps. , Daily morning, noon and evening, once in the evening, the amount of feeding is 60% of the whole day, at the same time depending on the situation of eating and drinking water and increase or decrease. After 25 days of transfer to the pond, the whole granule feed of Macrobrachium rosenbergii began to be fed, supplemented with bean cakes, wheat flour, bran, small fish, and crushed snails, and animal feeds accounted for more than 35%. The amount is 20%-40% of the body weight of the shrimp; two months later, it is fed at 5%-10% of the body weight of the shrimp. Twice a day, 30% of the total amount of rice in the morning and 70% in the afternoon, and appropriate feeding of duckweed, silkworm and other plant foods rich in citronin and other trace elements to meet the physiological growth of Macrobrachium rosenbergii need.
3.1.2 Carp Breeding In early November, when the carp is under the pond, the bait fish is also used at the same time. The specification is 25-50g of cheap white bream, carp fingerlings and loach, each of which starts to put 150kg in the mu and then gradually increases. Stocking 0.4-0.45 kg of 100 white pheasants. Feeding is carried out according to stages. Feeding once a week before fine weather in March, feeding 2 times per week in March, and feeding 15-20 kg per acre, depending on weather conditions in April. To ensure that the ratio of carp and bait fish tails is 1: (5-10), bait fish density is too thin, carp consumes too much physical strength due to predator bait fish, and does not reach the goal of full bait feeding; bait fish High density can easily cause anoxic floating heads. In order to ensure the year-on-year growth of uneaten bait fish, appropriate amount of rapeseed cake was also fed.
3.2 Fertilization and Water Quality Management
3.2.1 Shrimp culture Macrobrachium rosenbergii raises seedlings 5-7 days before Xiatang, applies 100 kg of fermented organic manure per acre to cultivate plankton and other natural baits; During the growing period, superphosphate is applied once every 20 days. Amount of 3-5kg per mu, but avoid mixing with lime or use during the same period. Generally, fresh water is added every 8-9 days after the pond is under the pond and the water level is increased by 8-10cm every other week. After two months, the water level is about 1.4m. In the hot season, some new water will be added every 2-3 days. In case of continuous low pressure or rainy days, new water should be replaced in time. Shrimp clams peak during the day, moderately reduced water levels during the day to facilitate the increase in water temperature, promote new shell hardening, fresh water in the evening, favorable shrimp clam shell growth. Every morning and evening, each patrol pond should pay attention to the change of water quality. Once it is found that shrimp swims and climbs to the shore, it should immediately inject new water or use oxygen aerators to increase oxygen, so as to prevent the death of fish and shrimp caused by lack of oxygen.
3.2.2 Aquaculture of aquatic products requires rich dissolved oxygen and fresh water. Add new water once every 15-20 days in winter, once every 10-15cm, once every 7-10 days in spring, every time 20-30cm, dissolved oxygen in water is kept above 4mg/L, transparency is kept above 0.4m.
3.3 Diseases and Predators
3.3.1 Common diseases of shrimp shrimp include carapace, black shank and ciliate diseases. After the onset of crustacean, change the pool or change the water in large quantities. Sprinkle with nitrofurazone at a concentration of 1 mg/L. After the onset of black shank disease, use malachite green with a concentration of 3 mg/L and feed with oxytetracycline; ciliate disease. Available copper sulfate and zinc sulfate (1:1) mixture 0.6mg/L Quanchiposa.
In prevention and control methods, ecological prevention should be the mainstay. For example, in the period of July-September, when the shrimp is in a fast growing period, appropriate amount of plants (such as black-leaf algae) can be regularly transplanted into the shrimp ponds. On the one hand, Macrobrachium rosenbergii can be provided with habitats and hidden places to avoid mutual survival of Macrobrachium rosenbergii. And on the other hand, it can also improve the ecological environment and maintain the ecological balance of shrimp ponds.
3.3.2 Prevention of carp disease There are anchored mistletoe during carp culture, but the damage is not significant. In the first 5 days of the lower pool, the pool water is spilled with 0.5 mg/L B type extermination. The carp is fed into the pond with salt water and malachite, and is prevented by a 0.25 mg/L monthly strong insecticide type I. . Because the carp is sensitive to most of the insecticides, pay attention to the changes of the fish when it is spilled, and feed the bait fish during the feeding process, but it is necessary to drink the fish after the bath.
4 Harvest and Benefits
4.1 Yield of Macrobrachium rosenbergii Macrobrachium rosenbergii was reared to the late autumn and early winter according to this model. During the entire breeding period, the feed amount per mu was 380kg, the feed coefficient was about 2.4, the survival rate of the shrimp was about 75%, the shrimp output was up to 160kg, and the output value was 8,000 yuan. The income of fish species is about 300 yuan; the cost is about 2280 yuan per kilogram of 6 yuan, and the artificial miscellaneous expenditures of electricity and pond rent are 1,000 yuan, and the net profit is 5,000 yuan.
4.2 Carp income Carp is raised to dry ponds at the end of April and beginning of May. During the breeding process, 600kg of bait fish and 200kg of vegetable cake powder are used in the aquaculture process. About 150kg of squid can be produced per mu (80% of commercial carp containing more than 0.4kg). Baiji 70kg, mu total income of 7800 yuan; spending sturgeon species 2300 yuan, eel and other bait fish 2400 yuan, feed, electricity, pond rent and other artificial miscellaneous count of 1,000 yuan, 2000 yuan per mu net profit.
5 Summary The total net profit per mu is more than 7,000 yuan in one year and two months, which is much higher than conventional aquaculture efficiency. It is a breeding mode worthy of further study. However, the following three issues must be paid attention to in production.
5.1 Macrobrachium rosenbergii breeding adopts early-flourishing seedlings for nesting of parent-mother pools, one-time breeding, multiple-fishing, and batch-listing farming models, which can extend the growth period of Macrobrachium rosenbergii by 1-2 months, and increase the market size of adult shrimps. Specifications and open sales period to avoid centralized listing and increase the selling price. The planting area of ​​spinach should not be too large, otherwise it will affect the photosynthesis of phytoplankton and lead to the lack of oxygen in the water body.
5.2 The baitfish should be rich in palatability, and the supply of baitfish should be at least 4 times the weight of commercial salmon.
The yield of catfish depends on the quality of the carp species:
(1) The specifications are neat, the fish is not injured, the surface is smooth, and there are no parasites;
(2) Control the stocking amount, increase stocking specifications, and increase the listing rate.
5.3 Inject fresh water frequently to keep the water fresh.
Macrobrachium rosenbergii is not tolerant to low temperatures. At the end of fall and winter, when the water temperature drops to 15°C, it needs to be picked up and listed in a timely manner. This way, the Macrobrachium praecox breeding pool actually uses only (5-10 months) for half a year. The carp does not completely stop in winter and continues to grow, but the intensity of feeding and growth rate slows. The use of Roche Macrobrachium aquaculture ponds to raise fish during the winter season, the stage of cheap seed, rich bait fish, carp raised to the following year in April and April listed, the price is relatively high. The implementation of Macrobrachium praecox and carp rotation can maximize the use of the idle period of fish ponds, increase the output rate of ponds and increase the breeding efficiency.