Fry breeding technique for yellow catfish
2018-04-27 17:00:12
Spawning and fertilization
The spawning fertilization time of the stingray is directly related to the water temperature, the type of oxytocin, the number of injections, the broodstock maturity, and microfluidic stimulation, and is particularly affected by the water temperature and the number of injections. In the optimum temperature range of 20-30°C, the effect of temperature increase with water temperature shortened; the time of two injections was significantly less than one injection. Stingrays produce sunless eggs with strong stickiness. Natural spawning Before the fertilization, lay artificial fish nests such as disinfected brown tablets, polyethylene gel silk, and dense mesh cloth. And to maintain the micro-water stimulation, to promote broodstock concentrated spawning. If artificial insemination is used, the male and female brooders should be removed after the effect time, and the abdominal cavity should be cut. The testes should be cut and ground, and a small amount of physiological saline should be added. The fish eggs should be poured into the fish eggs and evenly mixed and fertilized. After 2 minutes, the fertilized eggs were evenly distributed on the fish nests and soaked in a 3-5% formalin solution for 1-2 minutes before being transferred to the hatching tanks.
Artificial incubation
The fertilized eggs of the stingray were flat, light yellow, and the egg membrane was transparent. The egg diameter was about 2 mm. First, the fertilized egg is de-sticked with yellow muddy water. The specific method is: put the yellow mud into the basin with 200,000 - 300,000 fertilized eggs with 4-5 kg ​​of yellow mud (yellow mud: water = 1:5). The yellow mud is continuously stirred by hand, and the artificially fertilized eggs are gently poured into the yellow mud. After 5-6 minutes, the dehulled eggs are placed in the hatching tank or the hatching ring for running water hatching, per cubic meter. The water body can be put into 40-60 million eggs, the hatching pool wall should be kept smooth, the water quality is fresh, and the water flow rate can ensure that the fertilized eggs can be uniformly turned. The dissolved oxygen requirement in the water is more than 5 mg/L, and the regular washing and filtering is done. The screens can be stripped off after 4 to 5 days of incubation to form larvae with a body length of 4 mm.
The second method is to put the bred broodstock into a sterilized hatchery pond and set an artificial fish nest in the hatchery pond. After the eggs are produced, the broodstock is removed from the hatchery pond. The hatching pool is 0.5-0.7 meters deep and uses a combination of running water and still water. At a water temperature of 25-28°C, it takes 18-20 hours from the time the eggs are laid to rupture the fish. Oxygen pumps can be used to increase oxygen during incubation. To prevent saprophytic infection, daily disinfection with formalin solution at a concentration of 10 mg/l is used once. Afterwards, use 70-100 mg/L of solution in the morning and evening to sprinkle water on the water near the fish nest until the fry. hatch. After 24 hours of incubation, the fertilized egg adheres to the fish nest and develops normally. The unfertilized egg begins to turn white and loses its viscosity. It can shake the nest to shake off the dead eggs to prevent it from damaging the water quality or causing normal eggs to form water mold. Seedling rate. General water temperature 20-23 °C, after 60-70 hours began to film; 23-28 °C, after 50-60 hours out of the film, fish fry swim in the pool after the activities, timely fish out of the fish nest.
Fry raising
2 days after the fish was filmed, the cooked egg yolk was beaten and evenly sprinkled around the holding tank and gradually deepened to a depth of 0.8 m. After 4 weeks of conservation, the egg was put into a larger pond for cultivation.
The spawning fertilization time of the stingray is directly related to the water temperature, the type of oxytocin, the number of injections, the broodstock maturity, and microfluidic stimulation, and is particularly affected by the water temperature and the number of injections. In the optimum temperature range of 20-30°C, the effect of temperature increase with water temperature shortened; the time of two injections was significantly less than one injection. Stingrays produce sunless eggs with strong stickiness. Natural spawning Before the fertilization, lay artificial fish nests such as disinfected brown tablets, polyethylene gel silk, and dense mesh cloth. And to maintain the micro-water stimulation, to promote broodstock concentrated spawning. If artificial insemination is used, the male and female brooders should be removed after the effect time, and the abdominal cavity should be cut. The testes should be cut and ground, and a small amount of physiological saline should be added. The fish eggs should be poured into the fish eggs and evenly mixed and fertilized. After 2 minutes, the fertilized eggs were evenly distributed on the fish nests and soaked in a 3-5% formalin solution for 1-2 minutes before being transferred to the hatching tanks.
Artificial incubation
The fertilized eggs of the stingray were flat, light yellow, and the egg membrane was transparent. The egg diameter was about 2 mm. First, the fertilized egg is de-sticked with yellow muddy water. The specific method is: put the yellow mud into the basin with 200,000 - 300,000 fertilized eggs with 4-5 kg ​​of yellow mud (yellow mud: water = 1:5). The yellow mud is continuously stirred by hand, and the artificially fertilized eggs are gently poured into the yellow mud. After 5-6 minutes, the dehulled eggs are placed in the hatching tank or the hatching ring for running water hatching, per cubic meter. The water body can be put into 40-60 million eggs, the hatching pool wall should be kept smooth, the water quality is fresh, and the water flow rate can ensure that the fertilized eggs can be uniformly turned. The dissolved oxygen requirement in the water is more than 5 mg/L, and the regular washing and filtering is done. The screens can be stripped off after 4 to 5 days of incubation to form larvae with a body length of 4 mm.
The second method is to put the bred broodstock into a sterilized hatchery pond and set an artificial fish nest in the hatchery pond. After the eggs are produced, the broodstock is removed from the hatchery pond. The hatching pool is 0.5-0.7 meters deep and uses a combination of running water and still water. At a water temperature of 25-28°C, it takes 18-20 hours from the time the eggs are laid to rupture the fish. Oxygen pumps can be used to increase oxygen during incubation. To prevent saprophytic infection, daily disinfection with formalin solution at a concentration of 10 mg/l is used once. Afterwards, use 70-100 mg/L of solution in the morning and evening to sprinkle water on the water near the fish nest until the fry. hatch. After 24 hours of incubation, the fertilized egg adheres to the fish nest and develops normally. The unfertilized egg begins to turn white and loses its viscosity. It can shake the nest to shake off the dead eggs to prevent it from damaging the water quality or causing normal eggs to form water mold. Seedling rate. General water temperature 20-23 °C, after 60-70 hours began to film; 23-28 °C, after 50-60 hours out of the film, fish fry swim in the pool after the activities, timely fish out of the fish nest.
Fry raising
2 days after the fish was filmed, the cooked egg yolk was beaten and evenly sprinkled around the holding tank and gradually deepened to a depth of 0.8 m. After 4 weeks of conservation, the egg was put into a larger pond for cultivation.