Carp is a carnivorous rare fish species, and the seedling cultivation generally has the problem of low survival rate. The author engaged in the artificial propagation and nursery of eel for more than ten years. He realized that in order to increase the survival rate of eel breeding, attention must be paid to the following issues:
1. Seedling opening to develop the embryonic development of the seedlings until the disappearance of the yolk sac, just a swim you must eat a suitable bait fish. Therefore, synchronous breeding of open bait fish is the key to the success of breeding. In general, the head bait is used as a bait for the seedlings, and the head lice of the pueraria are used 24 hours after the puerpera are culled. In this way, when the seedlings are swimming flatly, the head seedlings that have been stripped soon become just suitable for the seedlings of the seedlings. Due to the seedlings swimming and opening lasting about 30 hours, the feeding of open bait should be carried out in the ring for 2 to 3 days. The daily amount of bait is 8 to 10 times that of the seedlings in order to increase the chance of predation.
2. Nursery ponds and seedlings Density nursery ponds can use hatchery loops and cement pools, with an area of ​​20 to 100 meters 2 and a water depth of 1 to 1.2 meters. They are equipped with inlet and outlet pipes, and overflow ports. The seedlings can be released into the pond within 3 days after opening, and the density of the seedlings is 2,000 to 3000 tails per meter of water. During the cultivation period, individual differences in seedlings are relatively large, and they should be kept thin according to the specifications to prevent the seedlings from killing each other. The density of seedlings about 2 cm is suitable for 800 to 1000 tails per meter of water.
3. Water Quality The quality of the nursery pond must be fresh and oligotrophic, with a dissolved oxygen level of 5 mg/l or more. During the cultivation period, due to large quantities of feed fish, dead fish residue and excrement perishable decomposition, resulting in deterioration of water quality, large consumption of oxygen, resulting in low dissolved oxygen syndrome, can easily cause seedlings ammonia nitrogen NH3-N poisoning and death. Therefore, nursery ponds are best to maintain micro-flowing water and mechanical oxygenation to avoid deterioration of water quality.
4. The bait fish should be fed to ensure that the bait fish is adequate and palatable. Except for the first 2 to 3 days of feeding the head of the head, 8 to 10 times, the third day to the 7th day is to feed the grass, oysters, and oysters. The daily amount of bait is 5-8 times of the seedlings. The fish of the family will be fed on cages for several days in the 8th to the 12th days. The amount of bait is 3 to 5 times that of the seedlings. After the 12th day, Miao Miaoda About 2 centimeters, you can feed about 1 centimeters of home fry "scorpion", the daily amount of bait for the seedlings can be 2 to 3 times. After about 20 days of cultivation, the seedlings can reach the summer flower specifications of about 3 cm.
5. Fish disease prevention and control During the entire nursery stage after the opening of carp, it is very easy to infect trichophathriasis and larval tuberculosis, and in severe cases, it causes a large number of dead seedlings in batches. Preventive measures: During the opening stage, daily use 80-100 mg/L formalin or 1.4 mg/L copper sulfate (microfluidic), and the nursery tank is soaked with potassium permanganate 10 mg/L for 48 hours, when the seedlings are in the pool. Disinfect the pot with a 100 mg/liter formalin bath for 5 minutes. During cultivation, adhere to daily observation with a microscope, every 1 to 2 days with 50 mg / liter of formalin or 1 mg / liter copper Quanchiposa (static water body requires mechanical oxygenation), have a better control effect. In the production of the above methods to do a good job of seedling cultivation and management of fish diseases, the survival rate of up to 80%.
1. Seedling opening to develop the embryonic development of the seedlings until the disappearance of the yolk sac, just a swim you must eat a suitable bait fish. Therefore, synchronous breeding of open bait fish is the key to the success of breeding. In general, the head bait is used as a bait for the seedlings, and the head lice of the pueraria are used 24 hours after the puerpera are culled. In this way, when the seedlings are swimming flatly, the head seedlings that have been stripped soon become just suitable for the seedlings of the seedlings. Due to the seedlings swimming and opening lasting about 30 hours, the feeding of open bait should be carried out in the ring for 2 to 3 days. The daily amount of bait is 8 to 10 times that of the seedlings in order to increase the chance of predation.
2. Nursery ponds and seedlings Density nursery ponds can use hatchery loops and cement pools, with an area of ​​20 to 100 meters 2 and a water depth of 1 to 1.2 meters. They are equipped with inlet and outlet pipes, and overflow ports. The seedlings can be released into the pond within 3 days after opening, and the density of the seedlings is 2,000 to 3000 tails per meter of water. During the cultivation period, individual differences in seedlings are relatively large, and they should be kept thin according to the specifications to prevent the seedlings from killing each other. The density of seedlings about 2 cm is suitable for 800 to 1000 tails per meter of water.
3. Water Quality The quality of the nursery pond must be fresh and oligotrophic, with a dissolved oxygen level of 5 mg/l or more. During the cultivation period, due to large quantities of feed fish, dead fish residue and excrement perishable decomposition, resulting in deterioration of water quality, large consumption of oxygen, resulting in low dissolved oxygen syndrome, can easily cause seedlings ammonia nitrogen NH3-N poisoning and death. Therefore, nursery ponds are best to maintain micro-flowing water and mechanical oxygenation to avoid deterioration of water quality.
4. The bait fish should be fed to ensure that the bait fish is adequate and palatable. Except for the first 2 to 3 days of feeding the head of the head, 8 to 10 times, the third day to the 7th day is to feed the grass, oysters, and oysters. The daily amount of bait is 5-8 times of the seedlings. The fish of the family will be fed on cages for several days in the 8th to the 12th days. The amount of bait is 3 to 5 times that of the seedlings. After the 12th day, Miao Miaoda About 2 centimeters, you can feed about 1 centimeters of home fry "scorpion", the daily amount of bait for the seedlings can be 2 to 3 times. After about 20 days of cultivation, the seedlings can reach the summer flower specifications of about 3 cm.
5. Fish disease prevention and control During the entire nursery stage after the opening of carp, it is very easy to infect trichophathriasis and larval tuberculosis, and in severe cases, it causes a large number of dead seedlings in batches. Preventive measures: During the opening stage, daily use 80-100 mg/L formalin or 1.4 mg/L copper sulfate (microfluidic), and the nursery tank is soaked with potassium permanganate 10 mg/L for 48 hours, when the seedlings are in the pool. Disinfect the pot with a 100 mg/liter formalin bath for 5 minutes. During cultivation, adhere to daily observation with a microscope, every 1 to 2 days with 50 mg / liter of formalin or 1 mg / liter copper Quanchiposa (static water body requires mechanical oxygenation), have a better control effect. In the production of the above methods to do a good job of seedling cultivation and management of fish diseases, the survival rate of up to 80%.