Artificial breeding technology

Channel catfish, also known as channel catfish, channel catfish, and American catfish. This fish has the characteristics of strong adaptability, fast growth, easy to raise, easy to catch and delicious meat. It is a world-famous culture species and sport fishing target. This fish is a large warm-water freshwater fish. It is an omnivorous fish that mainly feeds on plant food. In natural waters, its main food objects are benthic organisms, aquatic insects, zooplankton, rotifers, organic debris and large Algae.

Under artificial breeding conditions, it can eat all kinds of compound feeds, especially pellet feeds made from fish meal, soybean cake, corn, rice bran, wheat bran and other raw materials. Due to its extremely fast growth rate, feeding and management must keep up with it during different breeding periods to ensure the improvement of breeding efficiency.

1. Broodstock breeding period

During the broodstock breeding period, 4- to 5-year-old fish with strong physique and good growth performance should be selected as broodstock, and the ratio of male to female should be 1:1. Group. The broodstock pond covers an area of ??3 to 5 acres, and each acre is stocked with 60 to 80 broodstock, weighing about 150 to 200 kilograms. At the same time, a small amount of silver carp and bighead carp species are raised to improve the water quality of the pond.

Before the broodstock overwinters, intensive breeding measures should be taken to allow the broodstock to accumulate a certain amount of nutrients. This is not only the material basis for the broodstock to conceive eggs, but also enables the broodstock to survive the winter smoothly. In winter, as long as the water temperature is above 10°C, the broodstock can still eat a small amount, so it is necessary to feed some feed in an appropriate amount. Prenatal cultivation is the most important, that is, strengthening feeding and careful management after spring.

First, replace part of the pool water and add new water. After the water temperature rises, the parent fish will eat more and more vigorously. Therefore, it is necessary to gradually increase the feeding amount and appropriately add some animal feed, such as livestock and poultry offal, Small fish and shrimp etc. In order to increase the water temperature in the broodstock pond, the water level can be appropriately lowered, and at the same time, attention should be paid to increasing flushing.

2. Fry cultivation period

Temporary cultivation can be carried out 2 to 3 days after the fry emerge. The temporary breeding pond is preferably a cement pond with an area of ??1 to 2 square meters. Each square meter can temporarily raise 10,000 to 15,000 fry. There needs to be micro-flowing water in the pool. After 2 to 3 days, some palatable feed should be fed, with rotifers being the best. If insufficient, artificial powdery compound feed can also be fed. After the fry are temporarily raised for 5 to 6 days, they can be transferred to a special pond to cultivate summer flower fingerlings.

Summer flowers can be cultivated in a cement pool with running water or a smaller earthen pool with a water depth of 0.7 to 1 meter, and can be disinfected using conventional methods. After the drug toxicity disappears, apply base fertilizer to cultivate zooplankton. Before entering the pond, the fry should be bathed in 8 g/m3 copper sulfate solution for 10 to 20 minutes for disinfection. The running water cement pond can hold 8,000 seedlings per cubic meter of water, and the earth pond can hold 50,000 to 80,000 seedlings per acre.

Two to three days after the fry enter the pond, since there is abundant natural bait in the pond, there is generally no need to feed the fish, and artificial feed will be fed later. The main ingredients of artificial compound feed are fish meal, corn meal, soybean meal, vitamins and minerals, etc., and the protein content is required to be 35% to 40%. The daily amount of feeding should be determined according to the weather, water temperature, and the feeding situation of the fish. It is appropriate to eat it within half an hour after feeding.

During the entire fry raising period, new water should be injected frequently, the incoming water should be filtered, and the dissolved oxygen in the water should be maintained above 4 mg/L. After about 20 days of cultivation, the fry can grow into a summer flower fingerling with a body length of about 4 cm.

3. Fish breeding period

This stage is to raise the summer flowers for a period of time to cultivate them into large-sized and strong fish species. The suitable size of the fish pond is 3 to 5 acres, with a water depth of 1.3 to 1.5 meters.

The stocking methods are divided into two types: main breeding and mixed breeding. In the main breeding area, 6,000 to 8,000 summer flowers are placed in the main breeding area, and about 1,000 summer silver carp are placed in the mixed rearing area. There are about 2,000 silver carp summer flowers, 500 bighead carp summer flowers, and 1,000 to 1,200 grass carp summer flowers.

Polyculture is usually the best method, because silver carp and bighead carp mainly eat plankton. Polyculture with catfish species can not only prevent the plankton from multiplying in the pond and affect the water quality, but also improve the utilization rate of the water body and increase the number of fish. Total fish production. The feed is mainly artificial feed, with a small amount of organic fertilizer applied.

The feed should be processed into fine particles with a crude protein content of about 35%. The daily dosage is generally 3% to 5% of the total weight of the fish, and is fed once in the morning and once in the afternoon. During the breeding period, attention should be paid to appropriate water injection or water change to improve water quality and keep the dissolved oxygen in the pool water above 3 mg/L.

4. Adult fish breeding period

The survival rate of adult channel catfish breeding is high, the time is short, and the breeding conditions are not very strict. Mainly pond farming, with an area of ??3 to 6 acres and a water depth of 1.5 to 2 meters is appropriate. It can be raised alone or in mixed culture. Generally, mixed culture has better results. Fish suitable for polyculture with channel catfish include silver carp, bighead carp, grass carp, bream and tilapia.

In breeding, feed formula and feeding technology are very important to the growth of catfish. In-depth research has been carried out at home and abroad, and various feed formulas have been designed. The raw materials for processed feed in China mainly include fish meal, soybean meal, wheat flour and corn meal, etc., with crude protein content between 25% and 35%.

It is best to process the feed into two types of particles: sinking and floating particles. When the water temperature is above 15℃, feed floating feed; when the water temperature is below 15℃, feed sinking feed. Feed twice a day, once in the morning and once in the afternoon, and the feeding range should be expanded as much as possible.

Observe the feeding status of fish every day and adjust the feeding rate in time.

Channel catfish have relatively poor tolerance to hypoxia. In order to prevent floating heads and pool flooding, the pool water must be changed frequently to maintain fresh water quality. The dissolved oxygen in the water in the fish pond should always be maintained at 3 mg. /liter or more. Channel catfish can also be cultured in cages, often using secondary stocking.

The first level is raised from 10 centimeters long to a tail weight of 150 grams, and the second level is raised from 150 grams to 750 grams to 1500 grams. It can also be raised directly from 50 grams of fingerlings to adult fish. The stocking density of 8 cm to 10 cm fingerlings is 350 to 400 fish per square meter, and the stocking density of 150 g fish fingerlings is 150 to 250 fish per square meter.

Channel catfish are docile, have swarming habits, and are easy to catch. As the fish continue to grow, in order to adjust the breeding density and improve efficiency, they can be caught and put on the market in batches or in rotation.

In addition, channel catfish have many diseases, especially viral diseases, which are more harmful. Therefore, prevention must be the main focus. In addition to paying attention to routine disinfection, we must also insist on not feeding spoiled feed and regularly administer drugs. prevention. Intestinal sepsis is a common disease, and fish of all sizes are susceptible to infection. It can be treated by adding 0.18 kg of oxytetracycline per 100 kg of feed.

In addition, filariasis and melonworms are caused by filariasis and melonworms parasitizing the skin and gill tissues of fish. To prevent these parasites, 8 grams/g/ml should be used when planting seeds. Soak the fish body with square meters of copper sulfate for 15 to 20 minutes.

Extended information

Aquaculture management

1. For cage setting, choose waters with thin water quality and transparency of about 100 cm. The size of the cage is 3.0 meters The cage is made of sewn plastic mesh. 5 kg of sandbags are hung at each of the four corners of the cage. The top of the cage is covered with sunshade cloth, leaving a feeding port. There is a feeding frame for floating feed in the cage.

2. Fish fry stocking

After the cage is set up, soak the net clothes 7 days before placing the fry. Each cage is stocked with 21,900 fish. The fingerlings are soaked in 3% salt water for 5 minutes before entering the cage. During soaking, they are inflated with an air pump. The fingerlings have been acclimated to floating puffed feed before purchase.

3. Feeding and management

(1) Feeding of fish fingerlings begins in the evening of the day when the fish are released, and full-price pellets are fed. During the taming period, beat the fish with a wooden stick to make a sound, so that the fish will form a feeding conditioned reflex. The feed particle size is adjusted according to the growth of the fish species, the feeding amount transitions from 10% to 12% to 6%-8% in the first two weeks, and the feeding frequency transitions from the first 4 times/day to 2 times/day.

(2) Daily management: Insist on inspecting the cages every morning and evening to clean up residual feed and dead fish. When mouse traces are found or food intake suddenly decreases, the cages should be checked in time to prevent fish from escaping. If the disease is discovered, timely prevention and treatment , if the mesh is clogged, clean it in time to ensure the exchange of water in the cage, and keep records of water temperature, feeding amount, etc.

4. Fish disease prevention and control

Adhere to the principle of “prevention first, combined with prevention and treatment”. If the condition is discovered, it should be diagnosed immediately and corresponding preventive and treatment measures should be taken. The use of fishery drugs should adhere to the principle of "correct diagnosis and prescribe the right medicine". Drugs cannot be abused, the dosage of drugs cannot be increased at will, and the time of drug use cannot be extended.

Baidu Encyclopedia - Channel Catfish