The technique of cultivating puffer fish in pond

I. cultivation of small size fish species

(1) the selection of ponds requires that the water source is adequate, the water quality is pollution-free and the annual water temperature changes little. If brackish water or fresh water is used for aquaculture, ponds should be built in places with convenient water lifting, short route and low lift. The bottom of the pool basically does not leak and seep, so it is easy to build dikes and gates. In addition, it requires convenient transportation and power supply, there are no tall buildings around the pond, and it is not easy to be affected by storms or floods.

(2) Pond cleaning and disinfection drain the water from the pond in winter or during leisure time, dig out the silt from the bottom of the pond, and then expose it naturally. Clear the pond with quicklime and bleach to disinfect the fish before entering the pond. The dosage of quicklime per mu is 100kg-150kg, and the amount of bleach is 30-40ppm. A week later, water is stored and fish is released, and sufficient base fertilizer is applied to facilitate the reproduction and growth of plankton.

(3) Fish fingerling shall be reared indoors to 1.2-1.5 cm, with 10-20,000 fish per mu. If the transport distance is close, you can use plastic buckets with water to transport. If the transport distance is far, you can use plastic bags with oxygen, each bag contains 1000 tails. The transport time can ensure the survival rate within 7-8 hours. The best transport water is 3-5ppm salt water. The temperature should be above 18 ℃ when stocking. Pay attention to the temperature difference between the inside and outside of the bag should not be too large.

(4) Feed feeding and water quality control before the total length of fish species is 3 cm, 1 kg of soybean milk is fed per mu of ponds every day to reproduce plankton, provide sufficient bait for fish species, and pay attention to transparency, generally about 30 cm; water color mung bean color, the number of plankton in the water is rich, but not in groups or groups, can not be transferred in groups in the water. If there are too many bait organisms, new water should be injected to reduce the biological density and keep the water quality fresh. Through the effective regulation of dissolved oxygen and water quality, the size of most fish species can reach about 3 cm after 20 days in the pond. at this time, while feeding soybean milk to control bait organisms, eel is used to make soft particles the size of soybeans, and one grain is fed on the beach at an interval of 1 meter. in order to domesticate the habit of eating eel, large size fish should be cultivated sparsely at this time.

2. Large size fish culture

(1) Fish species transportation and stocking to ensure the quality of fish species, Fugu striata should be authentic. Individuals with strong physique, disease-free and injury-free, neat specifications and strong traceability were selected as stocking objects. The transportation is generally carried with oxygen in plastic bags. The seedlings of 3-4 cm are packed in 100-150 tails each, which can be transported for 5-8 hours, and the survival rate is more than 95%. It is best to disinfect the seedlings with 5ppm bleach or 1ppm malachite green for 10 minutes before stocking, and the temperature difference should not be too large. Dark grain oriental  should be sparsely reared. The stocking density of 3-5 cm fish pond is 2000-3000 fish / mu, the water source is sufficient, the water quality is good, and the pond with large water exchange capacity can appropriately increase the stocking density, which can be 3500-4000 fish per mu. With the growth of fish, gradually catch large and stay small, sparse culture.

(2) after domestication, the domesticated Oriental dolphin can be fed with minced bait fish, shrimp, snail meat, clam meat and so on. Within a week of stocking, fresh and palatable fish, shrimp and shellfish were used as open bait for domestication to gradually adapt to the breeding environment and feed composition. After the river  fish are used to eating, the artificial feed is gradually mixed into the bait, and the amount of artificial feed is gradually increased. Until the artificial feed is eaten completely, ensuring the freshness of the bait during domestication is the key to the success of domestication.

(3) Eel is the main bait, and the daily feed accounts for about 3% of the fish's body weight. The feeding position should be fixed (more feeding, less feeding and less feeding, based on the principle of fish satiety), constant speed (slow-fast-slow principle), and quality (bait palatable, fresh and clean). Usually bait twice a day. It is best to set up a food table in the pool in order to check the feeding situation in time. If there is still any remaining bait on the table two hours after feeding, it is necessary to reduce the amount of feeding. The table should be cleaned and exposed frequently to avoid the breeding of germs.

(4) Water quality controls the fresh environment of puffer water quality. Pond culture should add new water irregularly according to water color, water quality, transparency, dissolved oxygen and fish and shrimp activities, and change water once a month to improve water quality. As the suitable temperature range for the growth of puffer fish is 9-32 ℃, deep well water or river water with lower temperature should be injected to regulate the pool water temperature when the pool water temperature exceeds 32 ℃ in summer, and it needs to enter the greenhouse to overwinter when the pool water temperature is lower than 9 ℃ in winter. In addition, the puffer fish had higher requirements for dissolved oxygen. It began to float when the dissolved oxygen in the water was less than 1.5 g / L and died when the dissolved oxygen was less than 1.3 mg / L. the suitable dissolved oxygen should be kept above 3 mg / L. when the dissolved oxygen is deficient, an aerator or air pump should be used to increase oxygen.

(5) there are great differences in predation ability of river  with different sizes and sizes. Large individuals often attack small individuals during grazing, which seriously affects the feeding and growth of small individuals. Therefore, individuals of different specifications are divided into different breeds, which are generally carried out once every 30-45 days. Ensuring adequate feeding, timely separate culture and appropriate sparse culture can effectively prevent fish from killing each other and improve the survival rate of culture.

(6) daily management should persist in patrolling the ponds, observing the activities of the river , feeding and water color, water quality, and inspecting aquaculture facilities. The physical and chemical factors of water body were measured regularly every day. Such as water temperature, ph, dissolved oxygen, ammonia nitrogen, COD, PO4-P, transparency, etc., make daily records, in order to sum up experiences and lessons, and guide future production. The growth of fish was measured every 10-15 days and recorded as a reference for feeding. After 4.5 months of careful breeding, the size of the fish species can reach 100-150 grams in that year, and the survival rate can be stabilized at 85% Murray 95%.