The fork tail is native to North America and is a large-scale freshwater fish. It is also the main target of freshwater aquaculture in the United States. Its output accounts for more than half of the United States' freshwater fish production. China introduced channel catfish from the United States in 1984. , to be successful. It has the advantages of eating habits, fast growth, high yield, easy catching and raising, strong disease resistance, wide adaptability, superior meat quality, and it is worth promoting the cultivation.
Fry cultivation
The fry is cultivated to raise the fry into 4-5cm fish species, and the length of time is determined by the breeding technical conditions. Usually takes 25-30 days. Fry cultivation can be performed using stream cement ponds or general ponds, the former being generally used in small scale production. The latter is used in large-scale production. The following focuses on the method of cultivation of fertilizer ponds.
(1) The selection of fish nursery ponds and the conditions for clearing and disinfecting fish nursery ponds directly affect the rearing effect of the fry, so the fry ponds should be convenient for water injection and drainage, with topographical regularity, solid pool floor, good soil quality, no water leakage, and flat bottom , adequate amount of silt, well-lit fish pond. The area is suitable for 1-3 mu, and the water depth is 0.8-1m. In the first fifteen to twenty days prior to the fry hatching, the flocks must be cleared and disinfected to completely remove wild fish and other predators, and to create excellent environmental conditions for the fry to facilitate the survival and growth of the fry. When carrying out this work, the pool water should be drained first, wild wild fish and other predator creatures should be caught, the bottom of the pool should be leveled, debris in the pool and pool weeds should be removed, the pool pool should be reinforced, and the loopholes should be blocked. 5 days, backwater 3-5cm depth before pond disinfection. Commonly used disinfection drugs and dosages are: quicklime 50-75kg/mu, teacup 20-30kg/mu or bleaching powder (containing more than 30% efficiency) 5-10kg/mu, among which quicklime has the best effect.
(B) after the release of the base fat fish pond clearing and disinfecting, a week or so before the fry under the pool. In order to cultivate natural bait, base fertilizer should be applied in the pool by filling the pond first with water 70-80cm. Then the whole pool should be splashed with excrement or green manure be applied at the corner of the pool. 300-500kg of manure or 300-500kg of green manure can be applied per acre. It is advisable to control the mung bean green or yellowish green.
(3) After fry release and laying of basal fertilizer for 7-8 days, if the weather is normal, fish fry can be prepared. Clear fry insects, frog eggs, cockroaches and miscellaneous fish breeding in the rear pond of the pond should be cleared with dense eyes before stocking. , And then put a few live fish to test the water, only after confirming that the toxicity has indeed disappeared before the fry can be released. When ponds are under temperature, the temperature difference between the container and the water temperature should be less than 2°C. If the temperature difference is too large, the water temperature of the container should be adjusted so that it is close to the pool water temperature, and then the fry is released. Stocking density should be based on fry, water quality, fish pond conditions, feeding techniques and other conditions. The fish fry has good constitution, convenient water supply, adequate feed supply, good fish pond conditions, and high feeding technology, and the stocking density may be appropriately larger. It is generally more appropriate to stock 20-250 thousand per acre.
(D)Fry feeding and daily management
1. Feeding fry under the pond for 2-3 days, because the pool is rich in natural food, so do not need to feed, and later with the reduction of natural food and the growth of fish, artificial feed must be fed. The main ingredients of artificial compound feed are fish meal, corn flour, soybean flour, vitamins and minerals. The protein content is required to be 35% to 40%. Feed 3 to 4 times a day. The amount of daily feeding should be properly adjusted according to the weather, water temperature, and the fish’s feeding conditions. It is advisable to eat within half an hour after feeding. To reduce feed wastage, it is best to feed before feeding. Mix the powdered feed with water first and then feed it.
2. Daily management During fry keeping, we must strengthen daily management. We should constantly observe the activities of pond fish and the changes in water quality. We must take timely measures to prevent any unexpected problems. During the entire fry rearing period, the pool of dissolved oxygen should be kept at 4 mg/L. Above, staged water injection is an effective measure to improve the survival rate and growth rate of fry. Two to three days after the fry hatch, when artificial feeding is started, 10-15 cm of water must be injected into the pond. After every other week, water is injected once, each time the water injection is about 10cm, and finally the water is kept at a water depth of about 1.2m. When the water is injected, a dense net is used to filter wild fish and pests at the water injection port, and at the same time, water should be prevented from flowing directly into the bottom of the pool. Stir.
Two species breeding
When the fry is raised to 4-5 cm, the body weight has increased several dozen times. If it is still cultivated in the original pool, it will affect the further growth of the fish body because the density is too large. Therefore, separation must be carried out, and since the fish body is still small at this time, the defensive ability to enemy pests is still weak. If the fish is directly fed into large water surface or adult fish ponds, the survival rate will be reduced. Therefore, it is necessary to cultivate summer fish species. For large-scale fish species, it can then be used to provide cultured adult fish.
(I) Preparation of fish ponds The requirements of the fish ponds are similar to those of the fry ponds, but the area requirements are larger. The ideal area is 3-5 mu, the water depth is 1.3-1.5 m, and the clearing of the fish ponds is similar to the fry ponds. The fish species in this rearing stage are mainly artificially fed. Therefore, it is not necessary to apply basal fertilizer. The clearing and disinfection of fish ponds should be completed one week before the summer fishes are out of the pond.
(b) Summer flowering The stocking time of summer fish species is generally from July to August. There are two kinds of stocking methods, namely single-cultivation and eel breeding. It is better to use polyculture because the drawfish are mainly floating. The use of organisms for food and polyculture with channel-tailed fish can not only prevent large amounts of plankton in ponds from affecting water quality, but also increase the utilization rate of ponds. If long-distance transportation of summer flower species requires 1% to 3% brine treatment before stocking, then the pond can be depoted. The stocking density should be determined according to the expected pond size and pond conditions, and the required size of the pond should be small. In addition, if the production conditions are good, such as oxygen-increasing equipment, etc., the stocking density can be appropriately increased. On the contrary, the stocking density should be appropriately reduced. According to the experiment, 5000-7000 tail flowers per acre are stocked, along with 500-1000 tail fishes with similar specifications, and good feeding effects can be obtained;
(III) Feeding and daily management
1. During the feeding of fingerlings, it is necessary to feed artificial feeds. In order to improve the feed utilization rate, the compound feeds should be processed into fine particles (floating or sinking). The daily feed for the various stages is generally 3% to 5%. On the afternoon, feed each time. However, the amount of bait should also be adjusted according to the water temperature, water and fish feeding conditions.
2. Routine management (1) Each tour in the morning or in the afternoon, observe the water quality and the activity of the fish, measure the water temperature and dissolved oxygen on time, and understand the feeding dynamics. (2) Inject water or change water to water quality at a proper time. Keep the pool dissolved in oxygen at 3m to prevent anoxic pans. (3) Do a good job of flood prevention and anti-escape work.
Fry cultivation
The fry is cultivated to raise the fry into 4-5cm fish species, and the length of time is determined by the breeding technical conditions. Usually takes 25-30 days. Fry cultivation can be performed using stream cement ponds or general ponds, the former being generally used in small scale production. The latter is used in large-scale production. The following focuses on the method of cultivation of fertilizer ponds.
(1) The selection of fish nursery ponds and the conditions for clearing and disinfecting fish nursery ponds directly affect the rearing effect of the fry, so the fry ponds should be convenient for water injection and drainage, with topographical regularity, solid pool floor, good soil quality, no water leakage, and flat bottom , adequate amount of silt, well-lit fish pond. The area is suitable for 1-3 mu, and the water depth is 0.8-1m. In the first fifteen to twenty days prior to the fry hatching, the flocks must be cleared and disinfected to completely remove wild fish and other predators, and to create excellent environmental conditions for the fry to facilitate the survival and growth of the fry. When carrying out this work, the pool water should be drained first, wild wild fish and other predator creatures should be caught, the bottom of the pool should be leveled, debris in the pool and pool weeds should be removed, the pool pool should be reinforced, and the loopholes should be blocked. 5 days, backwater 3-5cm depth before pond disinfection. Commonly used disinfection drugs and dosages are: quicklime 50-75kg/mu, teacup 20-30kg/mu or bleaching powder (containing more than 30% efficiency) 5-10kg/mu, among which quicklime has the best effect.
(B) after the release of the base fat fish pond clearing and disinfecting, a week or so before the fry under the pool. In order to cultivate natural bait, base fertilizer should be applied in the pool by filling the pond first with water 70-80cm. Then the whole pool should be splashed with excrement or green manure be applied at the corner of the pool. 300-500kg of manure or 300-500kg of green manure can be applied per acre. It is advisable to control the mung bean green or yellowish green.
(3) After fry release and laying of basal fertilizer for 7-8 days, if the weather is normal, fish fry can be prepared. Clear fry insects, frog eggs, cockroaches and miscellaneous fish breeding in the rear pond of the pond should be cleared with dense eyes before stocking. , And then put a few live fish to test the water, only after confirming that the toxicity has indeed disappeared before the fry can be released. When ponds are under temperature, the temperature difference between the container and the water temperature should be less than 2°C. If the temperature difference is too large, the water temperature of the container should be adjusted so that it is close to the pool water temperature, and then the fry is released. Stocking density should be based on fry, water quality, fish pond conditions, feeding techniques and other conditions. The fish fry has good constitution, convenient water supply, adequate feed supply, good fish pond conditions, and high feeding technology, and the stocking density may be appropriately larger. It is generally more appropriate to stock 20-250 thousand per acre.
(D)Fry feeding and daily management
1. Feeding fry under the pond for 2-3 days, because the pool is rich in natural food, so do not need to feed, and later with the reduction of natural food and the growth of fish, artificial feed must be fed. The main ingredients of artificial compound feed are fish meal, corn flour, soybean flour, vitamins and minerals. The protein content is required to be 35% to 40%. Feed 3 to 4 times a day. The amount of daily feeding should be properly adjusted according to the weather, water temperature, and the fish’s feeding conditions. It is advisable to eat within half an hour after feeding. To reduce feed wastage, it is best to feed before feeding. Mix the powdered feed with water first and then feed it.
2. Daily management During fry keeping, we must strengthen daily management. We should constantly observe the activities of pond fish and the changes in water quality. We must take timely measures to prevent any unexpected problems. During the entire fry rearing period, the pool of dissolved oxygen should be kept at 4 mg/L. Above, staged water injection is an effective measure to improve the survival rate and growth rate of fry. Two to three days after the fry hatch, when artificial feeding is started, 10-15 cm of water must be injected into the pond. After every other week, water is injected once, each time the water injection is about 10cm, and finally the water is kept at a water depth of about 1.2m. When the water is injected, a dense net is used to filter wild fish and pests at the water injection port, and at the same time, water should be prevented from flowing directly into the bottom of the pool. Stir.
Two species breeding
When the fry is raised to 4-5 cm, the body weight has increased several dozen times. If it is still cultivated in the original pool, it will affect the further growth of the fish body because the density is too large. Therefore, separation must be carried out, and since the fish body is still small at this time, the defensive ability to enemy pests is still weak. If the fish is directly fed into large water surface or adult fish ponds, the survival rate will be reduced. Therefore, it is necessary to cultivate summer fish species. For large-scale fish species, it can then be used to provide cultured adult fish.
(I) Preparation of fish ponds The requirements of the fish ponds are similar to those of the fry ponds, but the area requirements are larger. The ideal area is 3-5 mu, the water depth is 1.3-1.5 m, and the clearing of the fish ponds is similar to the fry ponds. The fish species in this rearing stage are mainly artificially fed. Therefore, it is not necessary to apply basal fertilizer. The clearing and disinfection of fish ponds should be completed one week before the summer fishes are out of the pond.
(b) Summer flowering The stocking time of summer fish species is generally from July to August. There are two kinds of stocking methods, namely single-cultivation and eel breeding. It is better to use polyculture because the drawfish are mainly floating. The use of organisms for food and polyculture with channel-tailed fish can not only prevent large amounts of plankton in ponds from affecting water quality, but also increase the utilization rate of ponds. If long-distance transportation of summer flower species requires 1% to 3% brine treatment before stocking, then the pond can be depoted. The stocking density should be determined according to the expected pond size and pond conditions, and the required size of the pond should be small. In addition, if the production conditions are good, such as oxygen-increasing equipment, etc., the stocking density can be appropriately increased. On the contrary, the stocking density should be appropriately reduced. According to the experiment, 5000-7000 tail flowers per acre are stocked, along with 500-1000 tail fishes with similar specifications, and good feeding effects can be obtained;
(III) Feeding and daily management
1. During the feeding of fingerlings, it is necessary to feed artificial feeds. In order to improve the feed utilization rate, the compound feeds should be processed into fine particles (floating or sinking). The daily feed for the various stages is generally 3% to 5%. On the afternoon, feed each time. However, the amount of bait should also be adjusted according to the water temperature, water and fish feeding conditions.
2. Routine management (1) Each tour in the morning or in the afternoon, observe the water quality and the activity of the fish, measure the water temperature and dissolved oxygen on time, and understand the feeding dynamics. (2) Inject water or change water to water quality at a proper time. Keep the pool dissolved in oxygen at 3m to prevent anoxic pans. (3) Do a good job of flood prevention and anti-escape work.
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