Turbot is a marine benthic carnivorous fish of the family Amaranthidae, widely distributed in Europe, and inhabits seabed, gravel bottoms or mixed sediments at depths of 20 to 70m. Its round shape, faster growth than gums, strong resistance to disease, adapt to the water temperature below 24 °C. Is a cold-temperature fish, more suitable for settlement in the north, in the past few years at the double fishery company in Lashitun, Dalian, breeding and breeding, has accumulated some experience, are summarized below. 1 Breeding of broodstock In November 2002, broodstock was purchased from Norway. About 7.5kg per tail was placed in a circular culture pond with a volume of 50 cubic meters and a height of 1m. The bait was fresh and mixed fish and Vc and VE were added. Feed 2% of body weight and feed 2 times a day. Water temperature is controlled at 13.5°C. First, the pool was covered with black cloth. In order to save costs, several wells were drilled. The groundwater was used to regulate the water temperature, and the temperature of the boiler was increased by heating the boiler. A 200W lamp is used to control the light every 20m2 at 1m above the water surface. By March, the lights will be turned on at 7:00, and will be turned off at 16:00, and will be extended every 20 minutes to 12:00. The broodstock water is cultivated for about 3 months and the water exchange rate is 10%. Day-to-day management ensures that the bait is fresh, removes the bait in time, and prevents water spoilage. The parasite was found to have a 110E-6 trichlorfon medicine bath for 72 hours or a 20010E-6 formalin bath for 20 minutes. 2 Insemination and incubation of turbot require artificial insemination, because it can not spawn naturally, it is a spawning species in batches, once in 2 to 4 days, it should pay close attention to the broodstock dynamics, and then squeezing the eggs when the abdomen is uplifted in the middle of the abdomen. When the eggs are mixed, no water is added first. After standing for 5 to 10 minutes, add clean seawater, wash eggs 1 or 2 times, and filter with 80 mesh. Density is controlled at 200,000-300,000/m3, micro-flowing water, micro-inflating, larvae hatching at a water temperature of 15°C for about 120 hours. 3 Seedlings were raised and hatched 3 days after hatching. The fish was on the surface of the water and the body was slightly red, so it was called red seedling. At 5 days after hatching, earthworms are forming. At this time, the oil film on the surface of the water must be removed to inflate the earthworms. 10 days after hatching, the digestive tract was bent and the worms were inflated. The body was covered with black chrysanthemums and called black seedlings. In the first 10 days, hydrostatic or microfluidic water was used to cultivate and micro-inflate. The water temperature gradually rose to 16°C, and then the water exchange rate was gradually increased to 1/4 to 1/2, and the water change amount was 1/2 to 2 times at 10 to 35 days. At 35 days of age, the body of fish was 18 mm. The right eye rose to the top of the head and the worms became flat. At the age of 60 days, the body of the fish was 30-40.6 mm, and the right eye was raised to the left. The cockroach disappeared similarly to juvenile fish. The body color was shallow, and the planktonic life was ended. 90 days old is similar to adult fish. With regard to feeding, the main single-celled algae at 3 days of age are mainly algae of Isochrysis, 2 to 3 days later, rotifers, 5 to 20 per ml, 1 to 3 times per day, sustainable for 15 to 20 days, or even 25 days. We believe that increasing the rotifer feeding time can limit the factors that increase the size and size of the larvae, thus reducing the possibility of killing each other. It should be noted that because there are many rotifers, it is best to place them for 2 days before feeding, so that the rotifers empty the body's excrement, and then use a mesh bag to collect them. Rinse with water and check for no foreign matter before feeding. Can effectively prevent the occurrence of disease. 9 ~ 12d, can be cast halogen 0.5 ~ 1 / ml, lasting 20 ~ 25d to 35d after hatching. Pay attention to when you cast brine, egg shells must be handled clean, otherwise the egg shells are eaten by the early larvae, obstruct the digestive tract, and the fish cannot be discharged to cause death. The concentration of Chlorella added to the previous cultivation is 200,000 to 250,000/ml, which is conducive to maintaining the nutrition of the rotifer and reducing the transparency of the water. After 20 days, grain baits of 300-500 um in diameter were fed and fed at 4-6 g/d. Later, with the growth of fry, increase the grain size, and increase the amount of feeding. When three kinds of bait are put in at the same time, pay attention to the first feed with the bait, then the rotifer, and finally cast Artemia. Because the turbot has to eat live bait, do not eat dead bait; eat big do not eat small habits. This can make full use of food and reduce waste. 4 During the four death-prone periods of Turbot, caution should be exercised in the cultivation process. 4.1 The open-term mortality rate is 10% to 20%, which is caused by endogenous nutrient transfer to the external source. This is the reason why we believe that with the larval constitution Related, but also caused by careless operation. 3 ~ 7d when the bottom of the attention to the action should be light, slow, sucked out of the water is best to undertake with 100 mesh cages, leeches will be a small amount of sucked seedlings into the seedling pool, to prevent excessive fry were sucked away. 4.2 8 to 10 days after hatching, 60% to 80% of the mortality, analysis of larval fish normal opening and the quality of the external feed, the rotifer, especially bait, should be handled clean, the water quality remains fresh, and the water surface to prevent oil film. 4.3 16 to 18 days, 10% metamorphosis mortality after hatching. There are many reasons for the analysis. During the cultivation process, we must pay attention to keeping the water quality fresh and providing all-round nutritious food. 4.4 From 22 to 25 days, about 8% mortality occurred. The analysis was related to internal structure and environmental regulation of larvae. Careful attention is paid to the maturity of the egg, which of course is inseparable from the strong kin. Pay attention to investing less and less when investing in foods. We believe that this will increase the chance of feeding larvae, reduce the amount of residual bait, and reduce the pollution of pool water. Suction bottomers are handled with 100 mesh cages to ensure fresh water quality.
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