Culture technique of channel catfish (channel catfish)

Spotted cross-tailed catfish, also known as catfish, clamp fish, etc., is a large freshwater fish of the family Catfish, which has the advantages of miscellaneous diet, rapid growth, wide adaptability, strong disease resistance and excellent meat quality. it originated in North America and was introduced from the United States in 1985 for domestication. It was successfully bred in 1989. Let's take a look at the culture technology of Channel catfish.

Growth habits of channel catfish

Channel catfish can lay eggs under rock protrusions in rivers, lakes, reservoirs and ponds, or in caves of submerged trees, tree stumps, tree roots or river channels. They like to feed in groups under dark light conditions, and have the habit of eating at night and daytime. The water temperature is 4: 5 ℃, and stop feeding at 39 ℃. The growth temperature is 5 ℃, and the optimum growth temperature is 18 ℃. More than 3 mg / L of dissolved oxygen was better, floating head appeared at 0.8 mg / L and asphyxiation died at 0.34 mg / L. The pH value of normal growth is 6.5-8.9. Under the condition of pond culture, it grew to 13,35cm in the first year, 35cm in the second year and 4557cm in the third year.

Water quality requirements of channel catfish

1. Water source requirements: the common water sources for channel catfish breeding are groundwater and surface water. Generally speaking, groundwater is the best source of water for channel catfish breeding and hatching, because there is usually no suspended matter, no pollution, no pathogens, and the water temperature and hydrochemical composition are relatively stable. Surface water includes streams, rivers, ponds, lakes and reservoirs. Pollution-free surface water is better than groundwater as a source of water.

2. Water temperature requirements: the suitable temperature for fish egg hatching and fry cultivation is 26-28 ℃. If the water temperature is too low, the hatching period of fish eggs will be prolonged, and fungi will multiply in large numbers at low temperature, affecting the normal development of eggs. If the water temperature is too high, the deformity rate of fish fry will increase, and if the water temperature exceeds 28 ℃, fish eggs and fry are very prone to bacterial and virus diseases, so the hatching water temperature should be controlled at about 27 ℃.

3. Dissolved oxygen requirements: the amount of dissolved oxygen in the water used for incubation should be kept above 4 mg / L. in addition to full aeration before the source of water enters the incubator, inflatable facilities should be set up in the incubator to keep the water in the incubator circulating.

Cultivation of parent fish of channel catfish

1. Parent fish selection: during the parent fish cultivation period, 4-5-year-old channel catfish with strong physique and good growth performance should be selected as parent fish, which should be matched according to the ratio of male and female 1 ∶ 1. The area of the parent fish pond is 3 mu ~ 5 mu, with 60,80 parent fish per mu, about 150,200kg, and a small amount of silver carp and bighead carp species, in order to improve the water quality of the pond.

2. Overwintering management: before overwintering, intensive cultivation measures should be taken to make parent fish accumulate certain nutrients, which is not only the material basis for parent fish to conceive eggs, but also enable parent fish to survive the winter smoothly. In winter, as long as the water temperature is above 10 ℃, the parent fish can still eat a small amount of food, so it is necessary to feed some feed.

3. Prenatal cultivation: the most important thing is the pre-partum cultivation, that is, to strengthen feeding and careful management after the beginning of spring. First of all, replace part of the pool water, add new water, after the water temperature rises, parent fish intake is increasingly exuberant, so it is necessary to gradually increase the amount of feeding, and appropriately increase some animal feed, such as livestock and poultry viscera, small fish and shrimp, and so on. In order to increase the water temperature in the parent fish pond, the water level can be lowered appropriately, and attention should be paid to strengthening flushing.

Cultivation of channel catfish fry

1. Temporary culture management: Channel catfish fry can be temporarily reared 2 ~ 3 days after emergence. The cement pond with an area of 1 square meter is better, and 1 ~ 15000 fish fry can be temporarily reared per square meter. There is micro-running water in the pond, and some palatable feed should be fed after 2-3 days, of which rotifer is the best, and artificial powdered compound feed can also be fed when insufficient.

2. Summer flower cultivation: Channel catfish fry can be transferred to a special pond to cultivate summer flower fry after 5 days of temporary culture. Summer flower cultivation can be cultivated in cement ponds with running water or smaller soil ponds with a water depth of 0.7 meters. The zooplankton were disinfected by conventional methods and the zooplankton were cultivated with base fertilizer after the drug toxicity disappeared. Before entering the pond, the fish fry were bathed with 8 g / m3 copper sulfate solution for 10 minutes for 20 minutes and disinfected.

3. Stocking density: Channel catfish can release 8000 seedlings per cubic meter of water in cement ponds and 50-80 000 seedlings per mu in soil ponds. Fish fry 2-3 days after the pond, because there is a wealth of natural bait in the pond, generally do not need bait, and then feed artificial feed. The main ingredients of artificial formula feed are fish meal, corn meal, soybean meal, vitamins and minerals, and the protein content is required to be 35-40%.

4. Feeding management: the daily feeding amount of channel catfish should be determined according to the weather, water temperature and fish feeding, and it is appropriate to finish it within half an hour after feeding. During the whole fry feeding period, new water should be injected frequently, the influent water should be filtered, and the dissolved oxygen in the water should be kept above 4 mg / L. After about 20 days of cultivation, the fry can grow into summer fry with a body length of about 4 cm.

Rearing of channel catfish species

The main results are as follows: 1. Fish breeding: the stage of fish breeding is to raise the summer flower into a large size and strong fish species after a period of time. The suitable fish pond is 3 mu ~ 5 mu and the water depth is 1.3 m ~ 1.5 m. The stocking mode is divided into two types: main culture and mixed culture.

2. Stocking mode: 6000 ~ 8000 summer flowers per mu and about 1000 summer flowers in silver carp. There are 1000 ~ 2000 summer flowers per mu, 2000 silver carp, 500 bighead carp and 1000 ~ 1200 grass carp. It is usually better to use mixed culture, because silver carp and bighead carp staple food plankton, mixed culture with channel catfish can not only avoid the proliferation of plankton in the pond and affect the water quality, but also improve the utilization rate of water body and increase the total yield of fish species.

3. Bait feeding: artificial feed is the main feed, and a small amount of organic fertilizer is applied. The feed should be processed into fine particles with a crude protein content of about 35%. The daily dosage is generally 3%-5% of the total body weight of fish, and should be fed once in the morning and once in the afternoon. During the feeding period, we should pay attention to the appropriate amount of water injection or change of water, in order to improve the water quality and keep the dissolved oxygen in the pool water above 3 mg / L.

Adult feeding of channel catfish with channel catfish

1. Pond culture: the survival rate of channel catfish culture is high, the time is short, and the requirements for culture conditions are not very strict, mainly pond culture, with an area of 3 mu and a water depth of 1.5 meters. It can be either monoculture or mixed culture, and the effect of general mixed culture is better. The main fish suitable for mixed culture with channel catfish are silver carp, bighead carp, grass carp, carp and tilapia.

2. Feed configuration: the feed formula and feeding technology in channel catfish culture are very important to its growth. There are in-depth studies at home and abroad, and a variety of different feed formulations have been designed. The raw materials of feed processed in China are mainly fish meal, soybean meal, wheat flour and corn meal, with a crude protein content of between 25,35%.

3. Feed feeding: Channel catfish feed is best processed into two kinds of pellets: sinking and floating. When the water temperature is above 15 ℃, the floating feed is fed. When the water temperature is lower than 15 ℃, the channel catfish feed is fed with sinking feed. Feed twice a day, that is, once in the morning and once in the afternoon, the feeding range should be expanded as much as possible. Observe the feeding situation of fish every day and adjust the feeding rate in time.

4. Water quality management: Channel catfish has relatively poor tolerance to hypoxia. In order to prevent floating head and flooding pond, the pool water should be changed frequently to maintain fresh water quality, and the dissolved oxygen in fish pond should always be kept above 3 mg / L.

Net cage culture of channel catfish

1. Cage setting: select water with thin water quality and transparency of about 100 cm. The specification of the cage is 3.0cm 4.0m 2.5m, the effective depth is 2m, the double layer open structure, the outer layer is made of knotted mesh, the mesh is 2cm, the inner layer is made of 7 mesh rubber mesh, the four corners of the cage are each hung with 5kg sandbags, the top of the cage is covered with sunshade cloth, there is a feeding port, and the cage is equipped with a feeding frame for floating feed.

2. Fish fry stocking: after the cage is set up, soak the net coat 7 days before releasing the fry. 21900 fish are kept in each cage, and the fish are soaked in 3% salt water for 5 minutes before entering the box, and the fish are inflated with an air pump. The fish have been domesticated and fed with floating expanded feed before purchase.

3. Feed feeding: fish fry will be fed in the evening of the same day, and full-price granules will be fed. During the domestication period, a wooden stick is used to make a sound, so that the fish species form a feeding condition reflex. The feed size was adjusted according to the growth of fish species, the feeding amount was changed from 1012% to 60.8% in the first two weeks, and the feeding times were transferred from the first 4 times / day to 2 times / day.

4. Daily management: persist in inspecting the cage every morning and evening, cleaning up the residual feeding and dead fish, and when the rat trace or food intake is suddenly reduced, the suitcase should be checked in time to prevent the escaping fish. If the disease is found in time, wash it in time if the mesh is clogged, ensure the exchange of water in the cage, and record the water temperature and feeding amount.

Prevention and treatment of channel catfish disease

1. Viral diseases

[symptoms] the diseased fish had bleeding at the base of the skin and fin, abdominal swelling and yellowish exudate (ascites). Gill pale or bleeding, unilateral or bilateral exophthalmos. Such as anatomical examination, we can see that there are hemorrhagic areas in muscle tissue, liver, kidney and spleen. The spleen is reddish and swollen, and the stomach is enlarged with mucous secretions. The intestines are gray and white and there is no food. The diseased fish swam in a spiral, sluggish and suspended vertically in the water. The disease is highly contagious. The disease occurs when the water temperature is 30 ℃, which mainly harms the fish species less than 10 centimeters, and the young fish of 3 ~ 4 months old will also be infected. The course of the disease is usually 3-7 days. The mortality rate can reach 95% to 100%, and the remaining fish grow slowly.

There is no effective drug treatment for channel catfish virus disease. Lowering water temperature can reduce mortality, but it is not practical in production. Therefore, we should start with prevention, pay attention to stocking density and strengthen feeding management.

2. Hemorrhagic decay

[symptoms] the diseased fish swims in dull convulsions in the water, stops feeding, there are round and sparse ulcers on the body surface (skin and muscle necrosis), abdominal swelling, exophthalmos, body cavity filled with bloody fluid, kidney softening and swelling, liver gray with small bleeding spots, intestines filled with bloody or reddish mucus, hindgut and anus often have bleeding symptoms and swelling. The disease often occurs in spring or early summer.

[prevention] use the oxytetracycline solution of 2PPM to sprinkle the pool water. Every kilogram of fish was fed with 50 mg of oxytetracycline per day or 0.5 kg of garlic and 0.1 kg of salt for 5 days.

3. Edward's disease

[symptoms] in the early stage, the chest fin side of the diseased fish had an injury of 3 mm to 5 mm in diameter, such as needle-like trauma, and deep into the muscle. Within 10-15 days, the damage area gradually expanded, bacteria frequently invaded the blood of diseased fish or infected kidneys, and sick adult fish had foul-smelling gases in the injured muscles. The dead diseased fish is obviously related to the weakness of kidney and liver function. It is difficult to treat in the later stage of the disease.

[prevention and treatment] refer to hemorrhagic corruption.

4. Columnar disease

[symptoms] at the initial stage, there are injuries to the head of the diseased fish, or gray spots on the fins and slight congestion. When the symptoms expand, they become gray-white ulcers. The skin is completely eroded and the muscles are exposed. As the infection deepens, fish die. In addition, after the fin of the infected fish is corroded, the pathogen spreads to other parts of the body. Usually there is brown necrotic tissue at the end of the Gill filament and develops to the base of the Gill filament. Fungi can be used as secondary pathogens to invade these lesions.

[prevention and treatment] Bath with 1: 3% salt until the fish is restless.

5. Water mildew

[symptoms] grayish-white cotton-like mycelia grow in any part of the body of infected fish. Injuries caused by fishing, spawning and other operations or lesions caused by other diseases usually cause water mold to invade infection. The disease can occur all year round.

[prevention and control] at present, there is no effective control method. Try not to injure the fish during fishing, transportation and release. Bathe with 2% salt water, 2% baking soda for 10-15 minutes or 3% salt water for 15-20 minutes.

6. Fish bean disease

[symptoms] parasitic on the Gill and body surface. The parasitic site forms a gray or blue membrane by secreting too much mucus. Sometimes there is a secondary infection of bacteria. The disease can occur all year round, but it is more harmful when the water temperature is low.

[control] 15~25PPM formalin or sprinkle with 0.7PPM copper sulfate and ferrous sulfate (5 ∶ 2) in the whole pool.

7. Trichomoniasis

Parasitic on the Gill. In severe cases, the Gill tissue is swollen, anemic and sometimes rotten. It can cause great harm to both species and adults.

[prevention] sprinkle with 0.7PPM copper sulfate and ferrous sulfate (5 ∶ 2) in the whole pool.

8. Cucumber disease

[symptoms] watermelon disease is the most harmful disease. If the environmental conditions are suitable for the disease, all fish can be killed within a few days. After the small melon worm invades the skin and Gill tissue of the fish, it forms small white spots the size of a big needle, which can be seen with the naked eye. The disease is seasonal and suitable for the growth and reproduction of cucurbit disease when the water temperature is 20-25 ℃ in spring.

[prevention and treatment] 15PPM formalin mixture or soup made from ginger and pepper was sprinkled in the whole pool, once every 2 days for 1 to 3 courses of treatment.