How to breed sea bass artificially? What are the requirements for the culture environment?

Perch is one of the common economic fish. Its meat is delicious, rich in protein, vitamins, niacin, phosphorus and iron and other nutrients, can tonify the liver and kidney, spleen and stomach, can treat fetal movement restlessness, postpartum lack of milk and other diseases. Sea bass has the characteristics of fast growth, wide adaptability and strong disease resistance. it naturally feeds on small fish and shrimp, and artificial culture has high economic benefits. So how to breed sea bass artificially? What are the requirements for the culture environment?

1. Aquaculture environmental requirements

The sea bass culture pond area should not be too large, the pond is too small, the water body is narrow, the dissolved oxygen is insufficient, it is difficult to produce high yield; the pond is too large and too deep, which is disadvantageous to the production operation.

The sandy loam has less silt, the bottom of the pool is flat, tilted slightly to the outlet, the water depth is 1.54 meters, the drainage and irrigation system is perfect, the water source is sufficient, fresh and pollution-free, and the water quality is good. The pond had better set up intake and drainage gates, respectively leading to the inlet and drainage rivers, do not reuse aquaculture water, so as to avoid secondary pollution.

Divide the pond with a fine net to make it easy for fish fry to eat. Every 1.2 to 1.5 mu of water surface is equipped with an aerator, and a pump must be equipped to ensure that fresh water can be replaced at any time, and diesel generators should be used to prevent power outages and pond anoxia.

The ponds used for raising sea bass must go through dry ponds, desilting and exposure before releasing seedlings. One disinfection should be carried out half a month before seedling release, 150 jin of quicklime per mu or 20 mg / L bleach with appropriate amount of water disinfection. If not exposed to dry ponds, tea bran should be used to break and soak the whole pond and sprinkle; for those who have been exposed to dry ponds, about 10 cm should be released 10-15 days before stocking, with 80 kilograms of quicklime per mu and 5 kilograms of bleaching powder the next day, and the whole pond should be sprinkled with chemical water to clear the ponds and thoroughly remove wild fish.

two。 Cultivate and release fish fry

The time for releasing seedlings is from the beginning of December to March of the following year. The body length of sea bass caught from the sea area is 1.5-2cm, which can be desalinated to 4 ‰ ~ 7 ‰ before being put into a temporary culture pond with a salinity of 1 ‰. General stocking density is about 8000 fish per mu, choose to release seedlings at noon on a sunny day, when the water temperature and dissolved oxygen are higher, the discomfort of fish fry can be reduced, and the fish fry will be put into the prepared grid after disinfection with water. Because there are many baits in high-density culture and sea bass seldom look for leftover bait at the bottom of the pond, a small amount of crucian carp, tilapia or carp (omnivorous) and a small amount of silver carp (filter feeding) should be put in per mu after net removal, so as to reduce water pollution and increase culture efficiency.

The next day, the pond began to feed fresh bait such as zooplankton and red worms, slowly mixed fish paste, floating pellet feed and fresh bait, and then gradually domesticated to minced surimi and floating pellet feed. During the temporary recuperation period, 0.3 international units of strong chloroform or 15 international units of formalin were sprinkled and disinfected once a week. Three days before feeding, 0.5 grams of trimethoprim, 3 grams of oxytetracycline and 1 gram of vitamin C1 were given to every 50 kilograms of fish once a day.

After more than 20 days of feeding up to 4 cm and 6 cm, the stocking density is generally 2500 to 3500 tails per mu, and the water depth is more than 1.5 m. It is appropriate to maintain the suitable fertility of the pond water with transparency of 30 cm and oil-green water color. Feed twice a day, the main feed is minced surimi and floating pellet feed, vitamin B, C should be added to the feed, the daily feeding amount is 6% of the fish body weight. The baits of oxytetracycline, erythromycin and vitamins were fed twice a month for 3 days, and the whole pond was disinfected regularly with 0.4 international units of strong chloride or 20 international units of formalin. Do a good job in pond patrol management every day, turn on the machine to increase oxygen when the air pressure is low at night, and find that the pool water should be discharged and changed in time to keep the pool water fresh.

After releasing the fry to open enough to increase oxygen, it is best to use the bottom of the loose air stone to increase oxygen, generally do not add bait on the first day, and gradually start feeding after a day, requiring fixed-point fixed time, generally 4 meals, opening bait to water spider is the best, can also be fish paste mixed with part of eel feed opening, to fish fry 5-6 cm can be gradually fed inflatable material, fish fry stage feeding to add anti-enteritis drugs, the grid is gradually removed as the fry grows.

3. Strengthen daily management

When the adult length of sea bass fry reaches about 10 cm, the survival rate of adult fish culture in the pond is high, and the stocking specifications should be neat so as to avoid eating each other. The stocking density should be 1000-1500 fish per mu. At the same time, 40 large bighead carp, 20 silver carp and 200 Pengze crucian carp were cultured to make full use of the water, regulate the water quality and increase the yield.

The temperature from September to October is suitable for the rapid fattening stage of sea bass, and the regulation of water quality should not be ignored. After disinfection, the pond is filled with fresh water through a filter, the water depth is about 80 cm, and some compound fertilizers are applied to cultivate plankton. Bass is benthic fish, like to live in clean, high dissolved oxygen content (4mg / L, transparency in 30cm / 40cm). New water should be injected flexibly and timely according to water color and transparency. In the early stage, due to the small temperature and low temperature of the fish, the water quality is easy to control, and the cycle of adding and changing water can be longer. With the growth of fish and the increase of fish pond biomass, the pond should be patrolled frequently, new water should be injected frequently, and aerator should be used reasonably to increase oxygen.

Bait should be "fixed, fixed and quantitative". Generally, two meals a day should be fed, and a bait bridge should be built in the pond at 6: 7 in the morning and 6: 7 in the evening, and 80% of each meal should be fed normally. In case of high temperature and cooling, the amount of bait should be reduced appropriately, and the feeding and health status of the fish should be observed every time, so as to take contingency measures in time. The water quality should be kept fresh and the dissolved oxygen is sufficient, the bottom of the pond with high culture density is easy to leave a large amount of residual bait and excreta, the decomposition concentration of harmful substances is high, a large amount of oxygen in the water is consumed, and the number of oxygen-opening machines increases with the growth of fish. Biological agents can also be properly applied to effectively degrade ammonia nitrogen and nitrite to maintain good water quality. At night, especially at 2-3 o'clock in the middle of the night, the operation of the aerator should be inspected.

4. Scientific prevention of epidemic diseases

Perch likes to overeat and is prone to enteritis, so it is necessary to observe the increase and decrease of perch eating during the day to judge its health status. The abdomen of the diseased fish is dilated, the anus is red and swollen, and there is a yellowish mucus outflow from the squeezed abdomen, which is caused by feeding metamorphic feed or excessive feeding. The amount of feeding should be properly controlled to reduce the cost, avoid polluting the water quality and reduce the occurrence of gastrointestinal diseases. During the treatment, the diet should be reduced first, it is best to stop feeding a meal, and the bait mixed with general antimicrobials can be cured for 3 to 5 days. At the same time, inspect whether there are fish swimming, generally a large number of fish swimming before the disease, this is the best time to see a doctor and medication, but also a critical period of prevention.

It is easy to develop hepatobiliary syndrome in autumn, which is mainly manifested by reduced eating, gradual swimming of fish and unknown death. The main reason is that the drug application is frequent under high-density culture, and the toxic and harmful substances in the water accumulate chronically in the fish body, resulting in organ dysfunction and tissue damage. Or long-term overfeeding, fish liver long-term overload caused by metabolic disorders, metabolic disorders. It is necessary to regulate and control the water environment, feed it scientifically, and regularly use some Chinese herbal medicine for soothing the liver and promoting gallbladder to have a certain preventive effect.

Autumn is easy to suffer from parasitic diseases, should do a good job of disinfection and insecticidal work, generally once every 15 days, the frequency depends on the eating of fish. Parasitic diseases mostly occur in the body surface and Gill filaments of fish in the middle breeding stage, which is characterized by weight loss, blackening of body color and erosion of the mouth.

General parasites are easy to cause secondary bacterial infection, so it is generally necessary to disinfect after killing insects. Water exchange is often used to improve water quality for prevention. For treatment, 0.77 milligrams per liter of copper sulfate and ferrous sulfate mixture (5 ∶ 2) can be sprinkled evenly throughout the pond, or 20 milligrams per liter of formalin.