1, broodstock selection: Large yellow croaker sex distinction is not obvious, male sexual maturity. It is best to choose 2 or more years of winter, with bright colors and good vitality. Intensive breeding and ripening of broodstock: When the water temperature is lower than 15°C, move into the wintering ground, the water temperature is 161°C, and the male and female polyculture; from March to April, select some broodstock to carry out intensive cultivation, feed small live animal feeds, and spring The winter season is regularly cooked with drugs. Choose adult fish that has been bred for more than 2 years of age and has a body weight of over 500g, and has grown without grief. Intensive breeding will be performed. The selected broodstock will be placed in cages, and high-quality, fresh and mixed fish will be the main source, supplemented by formulated feeds. And add 1-2% fish vitamins. When the temperature of seawater is low in winter, the broodstock is moved into the indoor cement pool and fed with high nutritional feed such as oysters, sand and silkworms, while keeping the water fresh and making the probiotic fish appetite prosperous. During this period, prolonging the illumination time, increasing the temperature, hormone maturation and other methods to accelerate gonad development. Mature fish caught in artificial broodstock in the Guanjing Yanghai area during the May-June period of high tide period are fed through the cages, cultivated at room temperature or during the winter, and moved into the room for warming and intensive cultivation. Feed the VE-infused diet or injection. Emulsified VE and LRH-A were used to promote maturation, and the gonad development of broodstock was observed regularly. 2, artificial breeding artificial destruction of production: female abdomen enlargement and soft, male abdomen soft, light squeeze with semen. The oxytocic acid was used for salmonid pituitary, LRH-A, DOM ten SGARH, single or mixed, and injected once. The injection site is at the base of the pectoral fin without scales. The injection time is from 10 to 12 am. Spawning and fertilization: Use fresh filtered seawater, pre-inflated, and appropriate water flow stimulation during spawning; slowly swim before estrus and enter pre-estrus 30 hours later. The male fish enjoyed swimming in the upper and lower layers of the water. The female swims slowly and the gemmation hole sends out an infrared burst. In 35 hours, the broodstock begins to heat and the group chases. The estrus lasts 2 to 3 hours into a climax and continues until midnight, when it enters the spawning stage. During spawning, the females produce cloudy, fine-grained eggs. The males lie on their side and discharge semen. Fertilized eggs were collected: egg diameter 1150 ~ 365um, oil balls 319.8um or so, floating eggs; collected by 80 mesh cage water method or fishing collection method. Fertilized egg transport: Use 30L membrane bag plus 10L of seawater oxygen, plus foam box packaging and transportation, usually long-distance air transport plus car transport, short-distance car transport. Incubation: Micro-inflating, making it easy to turn the eggs up and down, density of 10 to 200,000 tablets / ton of water (70-80 million tablets / kg eggs), water temperature 20 ~ 2 °C, hatched after 32.5 ~ 5 hours. The larvae are 2.76mm long and have a brownish brown spot on the tail, which is a unique sign of the large yellow croaker. After 3 to 4 days, the worms appeared. At the water temperature of 22 to 5°C, the animals were allowed to feed on the third day. The opening bait is a rotifer. After 4 months, the gonads mature gradually and when the gonad maturation index (GS1) reaches 20%, Artificial ovulation can be performed. Urinary anaesthesia was applied before antenatal administration and the dose of LRH-A3 was 50-100. Natural fertilized eggs produced in pools are collected by running water or sieves and transferred to nursery ponds for hatching. At 18 to 4°C, the hatching process is approximately 27 to 42. During the spawning season, broodstock that can extrude mature eggs and semen was collected at the Guanjingyang spawning ground. Artificial fertilization was performed at the site of the law. The fertilized eggs were separated, transported back to the nursery room and screened again for hatching. In addition, from the broodstock that were cultivated by hand, the body of the female body was inflated and soft, the outline of the ovary was obvious, and the male fish could extrude the thick broth of the broodstock and injected with different dosage forms and doses after being anesthetized by eugenol. The hormones are then placed into the spawning pool at a male-male ratio of 1:1, continuously inflated, and periodically flushed to stimulate the natural spawning of the broodstock. The fertilized eggs are collected by the egg-laying method or the spawning method, and then counted into the incubator after being screened. Or pool. Cages microfluidic water incubation method, using 80 ~ 00 mesh nylon sieve made by the φ3863cm cylindrical hatching cage, hanging in a round pool of 1.0 ~.3m3, each box placed fertilized egg 3 ~ 10000 tablets, micro-inflated (0.7-1.0L/min) and microfluidic (0.6-1.8L/min), the eggs slowly roll in the box. In the cement pool hydrostatic incubation method, the fertilized eggs are hatched in a round pool of 5 to 10 m3 or a rectangular pool of 20 to 4 m3 at a density of 200,000 to 300,000 grains/m3, and a spa stone is laid at the bottom of each 1.5 m2 tank. Continuous micro-inflation, adding filtered seawater regularly. Incubation water temperature is controlled at 18 ~ 24 °C, salinity 23 ~ 30 ‰, and to avoid mutations, to prevent direct sunlight, regularly stop the air siphon the bottom of the eggs and dirt siphon. 3, seed cultivation environmental factors control: water temperature 10 ~ 32 °C, the optimum water temperature 20 ~ 28 °C, salinity 20 ‰ ~ 32 ‰, too low prone to deformity; sudden changes in light immediately appeared uneasy state, a lot of jump, childish The fish floats, and shock and death occur. The larvae and juveniles are becoming more prone to weak light. The light intensity should be controlled at less than 2000Lx, and the latter is particularly sensitive to light and should be controlled within 500 to 800Lx. Water quality conditions: using still water or running water to cultivate, early hydrostatic, 1/5 to 1/4 a day, larval rear with intermittent flow water, 2 times a day, after the increase of water flow, general water feeding 2 to 3 hours and then flow Ammonia nitrogen <0.3ppm, pH 7.8 ~ 8.5, dissolved oxygen is an aerolite/2m2. Feed series and feeding amount:: Nutrition requirements are determined by the size of the caliber and dietary changes. Rotifers, 2 to 5 days old 5/mL 5 to 10 days old 10 to 15/mL, 15 to 20 days old 20 to 25/mL, 20 days old and 10 post/mL; small before feeding The georgic algae is strengthened for more than 6 hours to increase the content of ω3 series of highly unsaturated fatty acids (ω3HUFA) in the rotifers, so as to meet the requirement of essential fatty acids (BFA) for growth and development of juvenile juveniles. Artemia nauplii, 13 to 20 days old 2/mL, 20 to 30 days old 5/mL, 30 days old and above 5 to 6/mL. Copepods, 13 to 35 days old 0.5 to 2 per mL. The meat carp is properly added with various nutrient additives, vitamins, and antibiotics, and different size particles are selected for feeding according to the size of the fish body. Feeding is 50g/million for 20 to 30 days and 80 to 100g/million for 30 to 45 days. 45-60 days old feeding 120g/million, the principle is a small number of times. The newly hatched larvae are nutritious for their own yolks and do not need to feed; on the third day after hatching, the larvae form mouths and anus and open their mouths to feed. The rotifers were cultured in/mL chlorella fluid and rotifer-specific nutrition for 12 hours, and 8 to 10/mL rotifer density was maintained in the water. At the age of 14 days, 0.5 to 1 aml/mL of Artemia larvae, which were fortified with nutrition, were added. At the age of 17 days, the copepods filtered by the 60-mesh sieve were started to be fed 30 to 50 g per 10,000 larvae per day and fed 5 to 6 times a day. After 43 days of age, the powdered bait was prepared by processing copepods and squid baits at a ratio of 1:1.5. For rotifer nutrition, according to the amount of rotifers needed to feed larvae, choose a suitable container and add (1500 to 2000) 104 chlorella per mL to control the concentration of fortified rotifers. 300～500 cells/mL; water temperature 22.0～24.0°C, suitable amount of gas, 15mL of 50DE microencapsulation of rotifer-specific nutrition enhancer per cubic meter of water body, add 5 to 10 times seawater in a beaker, add in the enhanced container, strengthen culture After 12h feeding. Artemia larvae nutrition enhancement, adding sand filter seawater container, Artemia larvae feeding density control in the 100 ~ 200 / mL; Artemisia specific insecticidal supplement 50DE microcapsules per cubic water body 30mL, inflated, enhanced feeding about 6h. Juvenile fish culture density: larvae 30,000 to 50,000 fish/m3 water body, juveniles 1 to 30,000 fish/m3 water body, larvae of 0.5 million fish/m3 water body; juvenile fish scales moved straight into the sea area after the scales Box culture. The earthen ponds cultivated seedlings: they were fed into the earth pond for 2 to 3 days after opening and the cultivation was continued. The earth pool should be cleared in advance and "fat water" should be prepared. Compared with indoor breeding, the soil seedlings grow faster and have better vitality. Body color is more vivid. Early larvae are reared at a high density in small concrete tanks of 20 to 30 m3, and later diluted in medium and large tanks of 50 to 60 m3. Breeding water temperature 18 ~ 28 °C, salinity 22 ~ 32, pH 7.8 ~ 8.2, dissolved oxygen 4mg / L, NH4-N <0.2mg / L, light <LX. In the beginning of raising seedlings, the water must be filtered through sedimentation, and the amount of water should be changed every day. The larvae period is 20%, the juvenile period is 50%, the larval period is 100%, and the sewage is often sucked and inflated. It is best to use water for cultivation. Larval larvae are open at 3 days old, rotifers are used as open bait, Artemia nauplii are fed at 13 days old, copepods and larvae can be fed at 16 to 20 days old, 30 to 40 days old, and the average seedling length is 3cm When you can, you can move to sea area cages for raising. Practice has shown that nauplii with egg shells have low nutritional value and are difficult to digest. The larvae that devour egg shells cause malnutrition, which leads to slow growth and development and affects water quality. Artemia fed into Artemia must be emulsified with cod liver oil, which has a high cost and may also affect the hatchability of Artemia. Therefore, the large yellow croaker bait series can be changed to rotifers (3 to 30 days after hatching)→ copepods (about 13 to 32 days). This will not affect the growth and development, the survival rate is high, and the production cost is reduced. The characteristics of the various stages of fry: Early larvae - a complete absorption from the hatching of the membrane to the yolk sac and oil globules for the larval nutrition transition period. The late larvae were absorbed from the yolk sac and oil globules until the fins developed. During the juvenile period, one fin fin was developed and scales were formed. The body length was 10.0 to 20.0 mm. Juvenile period - fish body rouged scales, the external appearance of fish like. The specifications and conditions for the tanks cultivated by fry: 1.0m3, 1.2m3, 2.3m3, 10m3 round pool, or 24m3, 34m3, 50m3 rectangular chamfer pool. Breeding conditions water temperature 20 ~ 28 °C, salinity 20 ~ 32 ‰. Avoid sudden changes in temperature and salinity. Use dual adjustable curtains to control the illumination from 1000 to 2000Lx to avoid sudden changes in illuminance and direct sunlight. Distribute air stones at 0.5-2/m2, try to make the bubbles fine, no dead zone, continuous inflation, aeration volume of 0.1-0.5 L/min before 10 days of age, followed by 2-10 L/min. The seawater used shall be subject to dark precipitation, sand filtration, and filtered into a pool using a 250 mesh bag. PH value of 7.8 to 8.5, NH4-N in the 0.310-6 or less, DO> 5mL / L. The density of larvae was 50,000 to 20,000/m3, the juvenile period was 1.5 to 0.800/m3, and the juvenile period was 0.6 to 0.3 million/m3. The daily management of fry cultivation: daily use of siphon pipe to suck bottom bait, dead seedlings, dung and other debris. Changing the water and cultivating the water, raise the elbow density in a round pool with a density of 2.3m3 or less. Continuous microfluidic water culture; large pond nursery, 10 days before the age of the water for quiet cultivation, combined with sewage suction water per day l ~ 2 times, each changing the amount of water is 20 ~ 30%, 10 days after the use of intermittent water culture. According to the water quality and the juvenile fish's constitution, water flow twice a day, exchange rate 0.5 ~ 1 times / day, juvenile fish period 1.5 times / day or more. Chlorella liquid was added regularly every day so that the pool water was maintained at 100,000 to 300,000 cells/mL, and “green water culture†was added to increase DO. Reduces NH4-N and transparency, and acts as a bait for rotifers, increasing the nutritional value of rotifers. Sampling method counting: After the larvae and juveniles are evenly distributed at night, use sampling pipes or wide-mouthed bottles to set sampling points in the upper, middle and lower four corners, in the middle of the four sides and in the middle of the pool. According to the growth and development stages of juvenile juvenile fish and the counting results, the cultivation density shall be adjusted in time to be diluted and bred. When using the larvae and juvenile fish, they use the characteristics of clustering of juvenile fish and tend to use water to remove the bait with water. Maintain the density in the nursery water body: According to different developmental stages of larvae and juveniles, no bait species are used. Rotifers - 2 to 5 days of age, 3 to 5 cells/mL; 5 to 10 days of age, 10 to 15 cells/mL; 10 to 15 days of age, 20 to 25 cells/mL; 10 cells after 30 days of age mL or so. Prior to feeding, the secondary intensive culture of Chlorella vulgaris at a concentration of 25 million cells/mL over 6 hours was used to increase rotifers. The content of ωlHUFA meets the requirement of fatty acids for growth and development of juvenile juveniles. Artemia nauplii 15 to 20 days of age above 2 / mL; 20 to 30 days of age 3 to 4 / mL; 30 days of age above 5 / ml, before feeding, emulsified fish liver oil nutrition enhancement. Copepods and their nauplii - Collected using planktonic webs of trapped plankton, after removing contaminants, sifting and feeding individuals according to the size of larvae, 0.2 to 1 animal per mL, minced meat, shrimp, and shellfish According to the size of juvenile larvae, different sizes of granules are selected, appropriate amount of multivitamins, antibiotics, fish oil, etc. are fed; the amount of feeding is adjusted depending on the food intake and other sources of feed, generally 20 to 30 days, 50 g/dillion. Tail 30 to 45 days old, 80 to 100 g/dillion, 40 to 60 days old, 120g/dillion. During the juvenile period, mix appropriate amount of squid compound feed.