CATDOLL : CATDOLL: Rainbow trout is an important cold-water fish that is widely farmed in the world. What are the techniques for farming rainbow trout?

Rainbow trout is an important cold-water fish that is widely farmed in the world. What are the rainbow trout farming techniques?

Aquaculture of rainbow trout

1. Parent fish breeding: water depth 1-1.5 meters, gravel bottom, water temperature 10-14℃, density 1-3 per square meter, male-female ratio 1:1. Change the water every day in the early stage of egg collection. Rainbow trout are afraid of light, so the light exposure is less than 12 hours a day. Feed vegetables in autumn and winter, animal feed accounts for 20%-30% of the total amount each year, plant feed accounts for 55%-70%, and some fresh small fish are fed before egg collection and sperm collection.

2. Artificial egg collection and fertilization: About one month before spawning, male broodstock can be seen fighting and chasing female fish. Female fish use their tail fins to dig pits and build nests in shallow water. Their body color gradually darkens, their cloaca is red and prominent, their abdomen is large, and they feel free eggs when touched. This means they are mature. The male fish's body color turns black, the mucus decreases, the cloaca is soft, and white semen flows out when the fish abdomen is lightly pressed. Stop feeding before dawn three days before egg collection. Eggs should be collected first and then semen. After egg collection, they should be rinsed with isotonic solution, and then the semen should be squeezed out. Stir gently with a feather for half a minute, add a small amount of fresh water, let the eggs be fully fertilized, stir slightly, add more fresh water, rinse the excess semen, and then add more fresh water. Let it stand for 30 to 60 minutes. After fertilization, pour it into the hatching tray for incubation. Avoid vibration during the period, and all operations should be carried out under light-shielding conditions.

2. Raising rainbow trout

1. Breeding farm: It must have ponds for fry, fry, fingerlings, adult fish and broodstock. Except for broodstock ponds which should be made of earth, cement ponds are preferred for other ponds.

2. Feeding and management: The key lies in dissolved oxygen, water temperature and feed. The dissolved oxygen should be above 6.4 mg/L and the water temperature should be 10-18℃. The newly hatched fish mainly absorb egg yolk. After 20 days, they start to eat by sprinkling broad bean milk on the upper reaches of the pond. They should eat small meals frequently. Two months after the start of feeding, crush the animal bones and liver and mix with a small amount of bean cake powder to feed. At the end of the year, it is the middle stage of the fish, when the food intake is large and the growth is the fastest. In the second year, it is the adult stage, and commercial feed is mainly used. In addition, the stocking density and water inflow and outflow should be adjusted according to the size of the fish.

3. Prevention and treatment of common diseases

1. Saprolegniasis: It occurs during the hatching period of fish eggs. Saprolegniasis grows on dead eggs, and the hyphae surround and infect healthy eggs. After 20 hours, the eggs suffocate and die.

2. Microcariasis: It is a common parasitic disease, and many small white spots can be seen on the body of sick fish.

3. Trichodiniasis: It parasitizes on the skin and gills and causes diseased fish to have difficulty breathing, gather at the bottom of the pond, and move slowly.

4. Trichodina disease: This disease attacks the skin and fins of fish species. Sick fish become extremely restless and struggle desperately from time to time.

5. Enteritis: Adult fish are prone to this disease. The intestines become inflamed, congested, red and swollen, and yellow mucus flows out when the abdomen is pressed lightly.

Pay attention to the water quality when breeding rainbow trout, pay attention to the water temperature, and try to keep it between 14 and 18 degrees. When the temperature is too low, do not feed the rainbow trout. Also, change the water in time to ensure sufficient oxygen. The water level should not be higher than 22 degrees, otherwise it will cause the death of rainbow trout. Once dead fish are found, clean them up and change the water in time.

This fish is a cold water fish. A cement pond should be built for this fish. This pond is very beneficial for the growth of fish. It has very high requirements for water quality, is resistant to nitrates and likes the bottom of the water. It is an omnivorous animal. It can be fed with some small fish and shrimp. It is bred by artificial insemination.

The water source must be broad, the breeding pond must be large, the water temperature must be suitable for the dispersion of fish, oxygen must be injected in time, sterilization and disinfection must be carried out regularly, and some fertilizers that fish like to eat must be fed, and scientific management must be carried out.

To choose a suitable temperature, the water temperature should be between 12 and 18 degrees Celsius. Pay attention to the clarity of the water, which should be pollution-free and free of sediment.

Do rainbow trout eat malachite green?

Rainbow trout generally do not eat malachite green alone, because rainbow trout is a carnivorous fish, so malachite green can be placed next to it and carefully mixed into the meat before feeding it to rainbow trout.

In the larval stage, rainbow trout mainly feed on zooplankton, benthic animals, and aquatic insects; adult fish feed on fish, crustaceans, shellfish, terrestrial and aquatic insects, and also eat aquatic plant leaves and seeds.

Malachite green, with the molecular formula of C23H25ClN2, is a synthetic organic compound and a toxic triphenylmethane chemical. It is not only a dye, but also a fungicide, bactericide, and parasiticide. It is effective against Saprolegniasis in fish and fish eggs. Currently, there is no effective drug on the market that can cure Saprolegniasis in a short time.