Nowadays, it is a golden time for fry reproduction, hatching, and fry cultivation. Seedling cultivation is a commonplace for fishermen. All fisheries have managed to improve the survival rate of fry cultivation in spring fry cultivation, but in recent years, fry cultivation has become a survival rate. It is generally low, usually only about 30%, which affects the aquaculture efficiency. The author believes that in order to improve the survival rate of fry, we should grasp the following ten points:
First, the fish fry pool selection of fry pool area of ​​20 square meters to 30 square meters, water depth of 1 meter to 1.5 meters, the pool embankment is solid, does not leak water, adequate water, convenient injection and drainage, fish pond to leeward, rectangular, east-west direction. The fry pool should not be too big, the water body should not be too deep, and it is easy to form wind waves. The fry will collide with the wall of the pool, affecting the survival rate, and it is difficult to increase the temperature of the deep water. When the area is too small, the water temperature changes quickly, and the living conditions of the fry are difficult. control.
Second, fry before stocking completely clear pond fry 10 days before stocking, pumping pool water, remove weeds, digging too much silt, with 1500 kg of chunks of lime per hectare after the whole pool spilled to kill bacteria, parasites And predator creatures. When entering the water, the inlet should be filtered with a double-layer dense net to prevent wild fish from entering the pool. After the fish pond is filled with water, it is necessary to regularly inspect the pond every morning to find the frog eggs and aquatic plants.
Third, the scientific quality of fish fry fry, directly affect the survival rate of fry, identify the quality of fry are:
1. In the hatching tank, the water body is stirred into a swirl, and the fry can swim against the water in the swirling edge as a good seedling.
2. Take a small amount of fry into the dish, the fry are lively and lively, the body is clean, the mouth blows the water, and the fry can swim against the water. After the water is drained, the fry is left in the bottom of the pan and is struggling. The head and tail are bent into loops as good seedlings.
Fourth, fry stocking to do the following:
1. "Test the water" After the stocking in the pond 1 day before the stocking, take a few fish fry in the fish pond cage, observe for 1 day, if the fish activity is normal, you can put the seedlings.
2. Fertilizer Pond The criterion for the fertilizer pond is that the zooplankton (rotifer) is in the peak of breeding period. After the fish is admitted into the pond, there is a natural food with sufficient palatables, which can improve the survival rate of the fry. After 6 to 7 days of fertilization in general fish ponds, rotifer breeding reaches a peak period, so the fertilization time should be 7 days to 8 days before the fry. If the water temperature is low, it can be 2 days to 3 days in advance, applying 200 kg to 300 kg of organic fertilizer per acre.
3. When feeding under the pond fish pond, two to three yolks are fed to each 10,000 fry, by placing the egg yolk into a slightly larger plastic basin, diluting the egg yolk with water, and filtering through a 40 mesh polyethylene mesh cloth. Afterwards, sprinkle evenly in the basin and wait for 20 minutes before putting it into the pool.
4. When the temperature of the pond fish seedlings is transferred to the pool mouth, note that the temperature of the oxygen bag and the fish pond can not be different by 3°C. If the temperature difference is too large, the oxygen bag should be placed in the fish pond until the water temperature in the bag approaches the temperature of the fish pond water, and then the fish fry slowly. Mixed into the pool. In case of storms, they should choose to lay their seedlings 2 to 4 meters offshore.
Fifth, the reasonable density of stocking fry cultivation of a general breeding pond only one species, not polyculture, fry 80,000 to 100,000 per acre of fry. Density is too low, can not fully use the water and bait; too high, the breeding process can easily lead to fry head or due to lack of food, inhibit the growth of fry.
Sixth, cast enough food, timely fertilization of fish fry cultivation mainly to soy milk, supplemented by fertilization. The amount of soymilk spilled was more than a few times, and evenly spilled. Every day, the bait should be “three times and two full ponds†(that is, three times a day, three times in which the whole pond should be splashed, and the whole pond should be splashed around once). Freshly ground, not to be put on hold for too long. Each kilogram of soybeans needs 3 kilograms to 4 kilograms per day. Five days later, in addition to the slurry, additional bean dregs, bean cakes and other fine ingredients are required. Fertilization can increase water nutrients and promote the growth and reproduction of natural food organisms. When the water quality of the fish pond is light and the natural food is not enough, it is necessary to top-dress fertilizers in time. General fish fry 5 days into the pool, every 2 to 4 days topdressing 1 times, each time organic fertilizer applied per acre 80 kg to 100 kg, to ensure that the fish pond has a certain natural food organisms for fish feeding.
7. Rehabilitation of water quality In the early stage of watering into the pond, the water depth is controlled between 40 cm and 60 cm, which is conducive to raising the water temperature and growth of the food organisms. After 7 days, water injection is conducted every 2 days to 4 days, each time 10 cm to 15 cm. , can expand the growth of fish fry, keep the pool water "fat, live, cool, tender". Water injection should pay attention to the flow of water into the pool straight, the water injection time can not be too long, so as not to prolong the flow of fish, consume physical strength, affecting growth or triggering the racehorse disease.
Eight, regular patrol ponds Each morning and evening patrol ponds one by one, observe the water quality conditions to determine the number of feeding and fertilization, observation of fish activity and growth, found that the disease should be promptly treated and removed.
Nine, do fish disease prevention and control work fry summer flower stage, the main fish diseases are horse disease, whitehead white mouth disease, white skin disease. During the cultivation period, lime water is splashed once every 5 days to 7 days. Each time, 15 kg of lime are used per acre to clarify the water quality and prevent fish diseases. When the racehorse disease is onset, it is possible to cut off the fry mad swimming route and stop the water injection, and increase the amount of feeding and fertilizer appropriately. When whitehead white beetle disease and white skin disease occur, 1 g/m3 of bleaching powder or 0.2 g/m3 of “strong chlorine†is sprayed per acre to disinfect the pool water for 2 days, and the pool is divided in time to reduce the pool density.
Ten, timely fry fish by 20 days to 25 days of cultivation, grow to more than 30 cm, the pool should be promptly divided, reduce the density of the pool to promote summer flower growth and improve summer flower out of the pool specifications. Before the summer flower goes out, it takes 2 days to 3 days to pull the net to exercise. Before pulling the net, it is necessary to stop for 1 day. The operation should be light and the speed should be slow.
First, the fish fry pool selection of fry pool area of ​​20 square meters to 30 square meters, water depth of 1 meter to 1.5 meters, the pool embankment is solid, does not leak water, adequate water, convenient injection and drainage, fish pond to leeward, rectangular, east-west direction. The fry pool should not be too big, the water body should not be too deep, and it is easy to form wind waves. The fry will collide with the wall of the pool, affecting the survival rate, and it is difficult to increase the temperature of the deep water. When the area is too small, the water temperature changes quickly, and the living conditions of the fry are difficult. control.
Second, fry before stocking completely clear pond fry 10 days before stocking, pumping pool water, remove weeds, digging too much silt, with 1500 kg of chunks of lime per hectare after the whole pool spilled to kill bacteria, parasites And predator creatures. When entering the water, the inlet should be filtered with a double-layer dense net to prevent wild fish from entering the pool. After the fish pond is filled with water, it is necessary to regularly inspect the pond every morning to find the frog eggs and aquatic plants.
Third, the scientific quality of fish fry fry, directly affect the survival rate of fry, identify the quality of fry are:
1. In the hatching tank, the water body is stirred into a swirl, and the fry can swim against the water in the swirling edge as a good seedling.
2. Take a small amount of fry into the dish, the fry are lively and lively, the body is clean, the mouth blows the water, and the fry can swim against the water. After the water is drained, the fry is left in the bottom of the pan and is struggling. The head and tail are bent into loops as good seedlings.
Fourth, fry stocking to do the following:
1. "Test the water" After the stocking in the pond 1 day before the stocking, take a few fish fry in the fish pond cage, observe for 1 day, if the fish activity is normal, you can put the seedlings.
2. Fertilizer Pond The criterion for the fertilizer pond is that the zooplankton (rotifer) is in the peak of breeding period. After the fish is admitted into the pond, there is a natural food with sufficient palatables, which can improve the survival rate of the fry. After 6 to 7 days of fertilization in general fish ponds, rotifer breeding reaches a peak period, so the fertilization time should be 7 days to 8 days before the fry. If the water temperature is low, it can be 2 days to 3 days in advance, applying 200 kg to 300 kg of organic fertilizer per acre.
3. When feeding under the pond fish pond, two to three yolks are fed to each 10,000 fry, by placing the egg yolk into a slightly larger plastic basin, diluting the egg yolk with water, and filtering through a 40 mesh polyethylene mesh cloth. Afterwards, sprinkle evenly in the basin and wait for 20 minutes before putting it into the pool.
4. When the temperature of the pond fish seedlings is transferred to the pool mouth, note that the temperature of the oxygen bag and the fish pond can not be different by 3°C. If the temperature difference is too large, the oxygen bag should be placed in the fish pond until the water temperature in the bag approaches the temperature of the fish pond water, and then the fish fry slowly. Mixed into the pool. In case of storms, they should choose to lay their seedlings 2 to 4 meters offshore.
Fifth, the reasonable density of stocking fry cultivation of a general breeding pond only one species, not polyculture, fry 80,000 to 100,000 per acre of fry. Density is too low, can not fully use the water and bait; too high, the breeding process can easily lead to fry head or due to lack of food, inhibit the growth of fry.
Sixth, cast enough food, timely fertilization of fish fry cultivation mainly to soy milk, supplemented by fertilization. The amount of soymilk spilled was more than a few times, and evenly spilled. Every day, the bait should be “three times and two full ponds†(that is, three times a day, three times in which the whole pond should be splashed, and the whole pond should be splashed around once). Freshly ground, not to be put on hold for too long. Each kilogram of soybeans needs 3 kilograms to 4 kilograms per day. Five days later, in addition to the slurry, additional bean dregs, bean cakes and other fine ingredients are required. Fertilization can increase water nutrients and promote the growth and reproduction of natural food organisms. When the water quality of the fish pond is light and the natural food is not enough, it is necessary to top-dress fertilizers in time. General fish fry 5 days into the pool, every 2 to 4 days topdressing 1 times, each time organic fertilizer applied per acre 80 kg to 100 kg, to ensure that the fish pond has a certain natural food organisms for fish feeding.
7. Rehabilitation of water quality In the early stage of watering into the pond, the water depth is controlled between 40 cm and 60 cm, which is conducive to raising the water temperature and growth of the food organisms. After 7 days, water injection is conducted every 2 days to 4 days, each time 10 cm to 15 cm. , can expand the growth of fish fry, keep the pool water "fat, live, cool, tender". Water injection should pay attention to the flow of water into the pool straight, the water injection time can not be too long, so as not to prolong the flow of fish, consume physical strength, affecting growth or triggering the racehorse disease.
Eight, regular patrol ponds Each morning and evening patrol ponds one by one, observe the water quality conditions to determine the number of feeding and fertilization, observation of fish activity and growth, found that the disease should be promptly treated and removed.
Nine, do fish disease prevention and control work fry summer flower stage, the main fish diseases are horse disease, whitehead white mouth disease, white skin disease. During the cultivation period, lime water is splashed once every 5 days to 7 days. Each time, 15 kg of lime are used per acre to clarify the water quality and prevent fish diseases. When the racehorse disease is onset, it is possible to cut off the fry mad swimming route and stop the water injection, and increase the amount of feeding and fertilizer appropriately. When whitehead white beetle disease and white skin disease occur, 1 g/m3 of bleaching powder or 0.2 g/m3 of “strong chlorine†is sprayed per acre to disinfect the pool water for 2 days, and the pool is divided in time to reduce the pool density.
Ten, timely fry fish by 20 days to 25 days of cultivation, grow to more than 30 cm, the pool should be promptly divided, reduce the density of the pool to promote summer flower growth and improve summer flower out of the pool specifications. Before the summer flower goes out, it takes 2 days to 3 days to pull the net to exercise. Before pulling the net, it is necessary to stop for 1 day. The operation should be light and the speed should be slow.
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