Bluegill Sunfish Artificial Propagation Technology

First, the broodstock breeding broodstock cultivation pool area of ​​2 acres, water depth of 15 meters, the bottom flat, the pool has a certain degree of natural slope, fresh water, convenient water, open environment, good lighting conditions. Choose two or more instars, adults with good sexual maturity, large individuals, robust physique, no disease, no injuries, and brightly colored adults to be used as broodstock. Acre stocking 800-1000. During the broodstock incubation, when the water temperature is above 18°C, the ponds are filled with water three times a week. 15 days before oxytocin injection, water was injected once a day for 2 hours each time to stimulate gonad development of broodstock. Feed chopped, high quality chilled fish every morning and evening to intensify cultivation. Fish ponds are diluted once every month with a concentration of 02 mg/litre of Quantit.
Second, pre-production preparation 1, the spawning pool will be an area of ​​106 square meters, the depth of 30 cm of rectangular concrete pool is divided into a number of small pool, set up a shading mesh, shading rate of 60% -70%. Before oxymostrine production, water disinfection shall be carried out first. For each cubic meter of water, 05 g of copper sulfate, 02 g of ferrous sulfate, 1-2 g of furazolidone, and 1-2 g of oxytetracycline should be soaked for 24 hours.
2. The hatchery pool shares 4 concrete pools, each with 66 square meters and a water depth of 50 cm. Disinfect the pool before hatching. The method is the same as the spawning pool. The top of the pool should be shaded to avoid direct sunlight and keep the water temperature stable, and there is an aerator.
3. The source of water for production and incubation is from the spare fish pond water, with fresh water and sufficient dissolved oxygen.
4. Production of artificial fish nests A layer of 30 cm 40 cm 60 mesh fishnet is first laid on the bottom of the spawning tank. This mesh is semi-floating and pressed with small stones at the bottom of the spawning tank. Lay the shade cloth on the water surface. Sunfish eggs will adhere to the mesh.
Third, the artificial oxytocin 1, the choice of mature broodstock Select 2 years of age or more, abdominal swelling and soft, elastic fish as broodstock. The abdomen is black and green, males, light pressure on the abdomen testis, genital hole milk white semen out, semen into the water that is scattered, indicating a good maturity; if the semen is too thick to enter the water does not spread, indicating poor maturity; if the semen is too thin, The ribbon is yellow, indicating maturity. The abdomen white is a female fish, and the lower abdomen is selected to be soft and elastic, with a clear outline of the ovaries, and the erythrocythma dehiscences for the female broodstock. The proportion of males to females is 1:1. The average body weight of each broodstock in this test is 152 grams.
2, oxytocin injection bred fish production using the second injection method. For the first injection, females were injected with 500 IU of chorionic gonadotropin per kilogram and 1 mg of pituitary pituitary. The male dose was halved and each tail was injected with 05 ml. After 24 hours, a second injection was performed. Females were injected with 1000 IU of chorionic gonadotropin and 2 mg of pituitary pituitary per kilogram, and the male was halved in dose, and 05 ml per tail was injected. 28 hours after the second injection of oxytocin, the broodstock began to spawn and fertilize. After 6 days of spawning, the eggs were evenly distributed on the net cloth.
IV. Artificial Incubation 1. Egg transfer The eggs covered with eggs shall be moved from the spawning pool to the hatching tank. The temperature difference between the two pools shall not exceed 2°C. If the temperature exceeds 2°C, use the water in the hatching tank to lightly apply to the mesh. The eggs are spattered to prevent the eggs from being washed away from the mesh, and after a period of time, the eggs can be adapted to the water temperature in the hatchery and they can be placed in the hatchery hatch. When incubating, allow the mesh to float in the water so that the fry can sink to the bottom when the fish fry.
2. Incubation and management The hatchery should maintain a slight water flow condition, and also need to open an aerator for 4 hours every day to maintain a high dissolved oxygen state. When the water temperature is 22-30°C, the seedlings are hatched after 36-50 hours. After the fry hatches, the mesh should be removed and microfluidic and aerated. When it was hatched, the seedlings did not eat at the end of the sink and they digested the yolk sac as nutrients. After 2 days, the fry floated to the surface and began to feed.
5. Spawning and Emergence Conditions 1. Spawning After the injection of oxytocin on May 1, 2001, some broodstock began to lay eggs on May 3, and each pair of broodstock spawned 1 nest until the broodstock laid eggs on May 8. Ended for 6 days, communist 15 nests.
2. During spawning and spawning, five litters were randomly sampled to calculate the number of egg yolks. On average, each litter produced about 7,000 eggs per female, and 15 females totaled about 1.05 million eggs. Calculating the fertilization rate was 86%, the number of fertilized eggs per litter was 6,020, and the total number of fertilized eggs was 900,000. After 38 to 42 hours of incubation, the fertilized eggs hatched with about 5320 fry, and about 780,000 fry were hatched. The hatching rate reached 868%. It was reared to 2-4 cm for sale. A total of about 600,000 2-4 cm seedlings were sold, and the survival rate was 77%.
6. Analysis and Discussion Generally speaking, March-October is the breeding season of the blue snapper sunfish, and April-August is the breeding boom of the blue snapper sunfish. The author chose to conduct an artificial propagation experiment in May, and the oxytocin production is relatively easy. Practice has shown that broodstock is not concentrated in spawning a day, from the beginning of spawning to the end of spawning, for 6 days, broodstock spawn every day. The results showed that the development of gonads was not synchronous and spawning was sequential, which was similar to the breeding habits of California salmon. To increase the hatching rate, the main concern is that in the hatching process, the hatching pool always maintains a micro-flowing state; daily use of an aerator increases oxygen for at least 10 hours; and the eggs in the mesh cloth are in a semi-floating state and do not sink to the bottom of the pool.