①pond conditions: general natural breeding ponds, or the use of low-yield farmland around the ditch embankment transformed into a water pond, the requirements of the environment is quiet, sunny, convenient drainage and irrigation, convenient land and water transportation, adequate water supply and water, water quality is fresh and pollution-free, in line with the standards of NY5051-2001.

② Facilities: escape wall with cement boards, aluminum panels for the enclosure, bamboo and wood pile support, fine wire stitching, soil on the part of 0.5 ~ 0.7 meters, soil under the part of 0.2 ~ 0.3 meters, the corners built arc. The two ends of the pond are divided into inlet and outlet. The inlet is located in the interface of the highest water level, with a cement culvert pipe into the pond; the outlet is located opposite the inlet. Inlet and outlet are sealed with wire mesh to prevent escape, the inlet also need to add a set of pipe bags made of sieve silk, to prevent hostile organisms with the water into. Larger ponds with 1 to 2 tons of cement boat 1, for baiting, fertilization and management. At the same time, equipped with pumps, oxygenators and caretaker room and other facilities.

③Set up a temporary feeding area: in the middle of the pond with a net around a total area of 1/10 ~ 1/5 of the temporary feeding area, used for planting grass before the temporary feeding of crab species, to be luxuriant growth of aquatic plants in the water before and after the withdrawal in May.

(2) stocking mode

①Silting disinfection: Before stocking seedlings, drain the pond, digging too much silt, after exposure to sunlight or freezing for 15 to 20 days, filtered and injected into the new water 30 to 50 cm, per mu of lime 100 to 150 kg dissolved in the whole pond sprinkled disinfection.

② fertilization water: with rotting organic fertilizer with a small amount of quicklime, piled up in the water depth of 30 to 40 cm, above the cover with the bottom mud, so that it is slowly released in the pool, can also be used to clean pollution-free fertilizers such as composite fertilizers, long-lasting fertilizer, such as treasure. The amount of fertilizer depending on the pool water silt and other conditions flexible, generally 100 to 200 kg of organic fertilizer per acre.

3 grass cast snail: before and after February planting Ella and sowing bitter grass, Ella with grass stems planted in the soil, bitter grass with grass seeds mixed with fine soil into the bottom of the pool. Generally planted 1 to 3 meters wide of Yiloba, leaving a blank band of about 2 meters. Sowed 1 to 3 meters wide bitter grass, 1 to 2 months to germinate, root, grow, and achieve luxuriant, and at the same time transplanted a few Artemisia or reeds and other water-supporting plants, the surface of the water transplanted to account for the total area of 1/5 or so of the aquatic peanut community. Put fresh snails into the breeding area before Ching Ming, 300 to 500 kilograms per mu.

④ Seedling stocking: see -2.

(3) Daily management

① Bait feeding: bait varieties of mussels, snail meat, small fish and shrimp, as well as wheat, cereals, cakes and pumpkins, sweet potatoes, aquatic or terrestrial fresh grasses and so on, but also full-value with feed. Baiting is flexible according to the weather, water quality, the amount of natural bait, the breeding species, the estimated amount of pond stock at a certain stage and the growing season. River crab to take "two fine, middle coarse", meat and vegetarian combination, a reasonable mix, fixed feeding method, feeding 1 time a day in the afternoon, the next day to check, the remaining decrease, insufficient to increase the general arrangement of daily feed feeding amount of about 7% of the weight of the pool crab. Mixed species mainly use the crab, fish feed and residual bait, generally do not specialize in baiting.

② water quality management: a water quality requirements. Transparency 30 ~ 50 cm, water color to fresh yellow-green is best, dissolved oxygen 5 mg / l or more, pH 7 ~ 8 neutral alkaline, ammonia nitrogen does not exceed 0.2 mg / l, nitrite 0.02 mg / l or less. Second, the water level. Adhere to the "shallow, deep, logistics" principle, that is, keep shallow water level in the early stage, in order to improve the water temperature, to promote moulting; in the middle of the summer, especially in the hot summer and fall, to maintain deep water level, always keep the water quality fresh, dissolved oxygen is sufficient. Third, add water to change water. Usually natural erosion, water level is too shallow, we should add water in time; water quality is too thick, it should be replaced in time with new water, especially in summer and fall, more diligent water change. Fourth, chemical and biological regulation. Regularly splash lime water in the whole pool and use photosynthetic bacteria, EM bacteria, chytridium and other biological agents.

③Disease control: put crab species with potassium permanganate or salt, fish species with bleach or trichlorfon and other drugs such as drug bath disinfection for 10 to 30 minutes. Growing season every 20 days or so, apply lime, 5 to 10 kg per mu each time, not only can disinfect and prevent diseases, but also improve water quality, adjust pH, but also increase calcium, promote the molt and growth of crab and shrimp. Growing season every month plus feeding 1 times the bait (50 kg of feed plus 25 grams of allicin, 2 times a day for 3 days). In addition, for fertilizer, water plants, tools, etc., often disinfected with bleach.

4 fishing temporary: adult crab fishing in October, take the hand-catching and ground cage Zhang catch a combination of fishing river crab temporary in the crab box to be sold. Green shrimp to implement the rotation of the market, regular fishing to reach 4 cm above the adult shrimp sales, in order to prevent the death of sexual maturity reproduction. Siniperca chuatsi, Pelteobagrus fulvidraco, warble mouth red _ to take the end of the dry pond catching and centralized harvesting.

(4) breeding key points and precautions

1) pay attention to planting grass cast snail: "crab size, look at the water plants". The water plants in the aquaculture pond not only increase the hiding place, but also can be used as plant bait. The species of water plants include bitter grass, rotunda black algae, Erythrina and water peanut. Hydrilla covers 60% to 70% of the pond area. Excessive hydrilla should be removed, especially Illicium, which grows vigorously and is easy to seal the water surface, especially in the later stage when the channel should be cleaned regularly. Snail is a high-quality natural basic bait for crabs, in the crab water body and crab **** life, both can purify the water quality, but also fresh bait for crabs to feed freely. It should be supplemented appropriately during the feeding period depending on the feeding situation of the crabs.

②Appropriate feeding set of fish bait: Siniperca chuatsi, Pelteobagrus fulvidraco, warble-billed red _ although they are all carnivorous mainly ferocious fish, but their food structure is different. Siniperca chuatsi life to live fish, shrimp as bait, mainly feeding on small bottom fish, such as crucian carp, loach, roach, etc.; yellow catfish in the crab pool in addition to feeding on live fish, shrimp, but also ingested artificially fed whelk or fish slurry and plant feed mix; warble beak red _ in the crab pool in the main intake of small fish in the middle and upper layers, such as silver carp, bighead carpet, and other summer flowers, at the same time, but also ingested artificially fed on the dead or ice fish feed, and other fodder. Therefore, in crab pool mixing, bait can be fed appropriately in order to improve the production and specification of valuable fish.

③Cautious use of drugs: Siniperca chuatsi and Pelteobagrus fulvidraco are more sensitive to drugs, so the use of fishery drugs should be selective and the amount of drugs should be calculated accurately. Especially in the high temperature season, it is more prudent to use a low dosage or no drugs usually. The drugs used in the whole process of aquaculture must comply with NY5071-2002 standard. Siniperca chuatsi is prone to anoxic floating head, such as serious floating head will lead to total destruction. Therefore, the water quality should not be too fat, regularly refill new water, keep the pool water fresh, high dissolved oxygen is the key to the success or failure of mixed culture.

This article is from: China Agricultural Publishing House, Species Resource Inspection and Identification