Rainbow trout, commonly known as trout, is a species native to California's Pacific coast. Rainbow trout meat is delicate, delicious, nutritious, and high in aquaculture production. It is one of the most widely cultivated species in the world today.
Rearing
Juvenile rearing. At this stage, the body length of the fish can reach about 3cm. The activity and feeding capacity of juveniles are gradually enhanced. The depth of the fish pond is 40-50cm, and the stocking density is about 1000 tails per square meter. After 25-30 days of feeding, the fish is sieved according to the growth speed of the young fish. Divide the pool.
The juveniles are fed with wild fish and liver of livestock. They are twisted 2-3 times with a meat grinder to make a paste. They are put on a thin iron gauze and hung in the water. The daily feed accounts for 6% of the total weight. 12%, feeding 4 times a day.
Fish breeding. Up to 6 cm in body weight, fish weight of about 3g digestibility similar to adult fish. The water depth is 80cm, and the soil level of the earthen pond can be increased appropriately, with a stocking density of 200-300 tails per square meter.
The fingerling stage should be fed artificial pellet feed. Feed ratio: 50% for animals and plants. Animal feedstuffs include fish meal, meat meal, small trash fish, cocoon and livestock, and livestock viscera, etc.; vegetable feedstuffs include bean cake flour, bran, sugar, green vegetables and eucalyptus leaves. The particle size is generally 2-4mm in diameter and is fed 3-4 times daily. Feeding accounts for 6% of the total weight of the fish.
Feeding of adult fish. The rearing method of the fingerlings of the adult fish and the tail is similar. The stocking density is 1-3 tails per square meter and the water depth is 1-2m. In animal feed, animal feed accounts for 60%-70%. The particle size is palatability, usually 4-8mm in diameter; it is fed twice a day and the amount fed is 1% of the total fish.
Reproduction
Rainbow trout are generally mature for 3 years and have spawned for 2 years. The females are close to the spawning period, with fresh sidelines, loss of appetite, and caudal fins swimming at the bottom of the pool. Males bite each other, chasing females, and the waves that evoked by diving are often seen in the water.
Select mature broodstock, male and female, respectively, into the cage, keep the water temperature 5 °C -12 °C. Male and female fish in the appearance of the main differences: body color: during the spawning period male body melanin significantly increased body color black; female fish melanin increase is not obvious, body color is slightly darker. Head: The male has a large head and a large mandible that flexes upwards to cover the upper jaw. Females have smaller heads and smaller mouths. Cloaca: Male fish vent holes are prominent, showing red; females are not prominent, no color change.
Egg collection method: One person grasps the male fish with its head up, its abdomen down, and is aligned with the ovulation basin. One person holds the clean basin and gently presses the posterior edge of the ovary in the direction of the excretory hole. The fish eggs flow into the basin. The egg-squeezing process should be light and fast to avoid broodstock injury; then the same method gently squeeze the back of the abdomen of the male, squeeze the sperm into the basin, stir with feathers for 30 seconds, so that the two are in full contact, then add a small amount of fresh water After stirring, allow to stand for 1-2 minutes, then add a lot of fresh water, wash off the excess body solution and semen, and then add the appropriate amount of fresh water to stand, absorb water for 4 hours, and then fertilize the fertilized egg into the hatchery tray for incubation. Need to be shading.
Fish Disease Prevention
When the red snapper appears to be weak in swimming, lying at the bottom of the pool, the body is dark, white or partially white, and the food intake is reduced, it is an external manifestation of the incubation period of fish disease, and diagnosis and treatment should be promptly conducted.
Bacterial rickets: One of the major diseases, the weight of about 100 grams is the most susceptible. Symptoms: Inactive fish, no appetite, hemorrhage at the beginning of the disease, and excessive mucus. Prevention: Use 0.5% copper sulfate bath for 1-2 minutes, or 1ppm copper sulfate bath for 1 hour.
Vibriosis: a disease that is extremely endangered and is prone to late spring and autumn. The base of the body surface and fins gradually darkens at the onset of the disease, and the anal surface of the base of the fin has bleeding. In severe cases, the epidermis collapses and exposes necrotic muscles. Treatment: 75-100mg of sulfa drugs per kg, fully mixed with feed and fed continuously for one week.
Kidney disease: A disease unique to carps. The pathogen is Gram-negative double bacilli. Symptoms: Prominent eyes, red and yellowish pus in the affected side of the body, and white bulge in the necrotic area. The prevention and control method is to sulfa drugs.
Rearing
Juvenile rearing. At this stage, the body length of the fish can reach about 3cm. The activity and feeding capacity of juveniles are gradually enhanced. The depth of the fish pond is 40-50cm, and the stocking density is about 1000 tails per square meter. After 25-30 days of feeding, the fish is sieved according to the growth speed of the young fish. Divide the pool.
The juveniles are fed with wild fish and liver of livestock. They are twisted 2-3 times with a meat grinder to make a paste. They are put on a thin iron gauze and hung in the water. The daily feed accounts for 6% of the total weight. 12%, feeding 4 times a day.
Fish breeding. Up to 6 cm in body weight, fish weight of about 3g digestibility similar to adult fish. The water depth is 80cm, and the soil level of the earthen pond can be increased appropriately, with a stocking density of 200-300 tails per square meter.
The fingerling stage should be fed artificial pellet feed. Feed ratio: 50% for animals and plants. Animal feedstuffs include fish meal, meat meal, small trash fish, cocoon and livestock, and livestock viscera, etc.; vegetable feedstuffs include bean cake flour, bran, sugar, green vegetables and eucalyptus leaves. The particle size is generally 2-4mm in diameter and is fed 3-4 times daily. Feeding accounts for 6% of the total weight of the fish.
Feeding of adult fish. The rearing method of the fingerlings of the adult fish and the tail is similar. The stocking density is 1-3 tails per square meter and the water depth is 1-2m. In animal feed, animal feed accounts for 60%-70%. The particle size is palatability, usually 4-8mm in diameter; it is fed twice a day and the amount fed is 1% of the total fish.
Reproduction
Rainbow trout are generally mature for 3 years and have spawned for 2 years. The females are close to the spawning period, with fresh sidelines, loss of appetite, and caudal fins swimming at the bottom of the pool. Males bite each other, chasing females, and the waves that evoked by diving are often seen in the water.
Select mature broodstock, male and female, respectively, into the cage, keep the water temperature 5 °C -12 °C. Male and female fish in the appearance of the main differences: body color: during the spawning period male body melanin significantly increased body color black; female fish melanin increase is not obvious, body color is slightly darker. Head: The male has a large head and a large mandible that flexes upwards to cover the upper jaw. Females have smaller heads and smaller mouths. Cloaca: Male fish vent holes are prominent, showing red; females are not prominent, no color change.
Egg collection method: One person grasps the male fish with its head up, its abdomen down, and is aligned with the ovulation basin. One person holds the clean basin and gently presses the posterior edge of the ovary in the direction of the excretory hole. The fish eggs flow into the basin. The egg-squeezing process should be light and fast to avoid broodstock injury; then the same method gently squeeze the back of the abdomen of the male, squeeze the sperm into the basin, stir with feathers for 30 seconds, so that the two are in full contact, then add a small amount of fresh water After stirring, allow to stand for 1-2 minutes, then add a lot of fresh water, wash off the excess body solution and semen, and then add the appropriate amount of fresh water to stand, absorb water for 4 hours, and then fertilize the fertilized egg into the hatchery tray for incubation. Need to be shading.
Fish Disease Prevention
When the red snapper appears to be weak in swimming, lying at the bottom of the pool, the body is dark, white or partially white, and the food intake is reduced, it is an external manifestation of the incubation period of fish disease, and diagnosis and treatment should be promptly conducted.
Bacterial rickets: One of the major diseases, the weight of about 100 grams is the most susceptible. Symptoms: Inactive fish, no appetite, hemorrhage at the beginning of the disease, and excessive mucus. Prevention: Use 0.5% copper sulfate bath for 1-2 minutes, or 1ppm copper sulfate bath for 1 hour.
Vibriosis: a disease that is extremely endangered and is prone to late spring and autumn. The base of the body surface and fins gradually darkens at the onset of the disease, and the anal surface of the base of the fin has bleeding. In severe cases, the epidermis collapses and exposes necrotic muscles. Treatment: 75-100mg of sulfa drugs per kg, fully mixed with feed and fed continuously for one week.
Kidney disease: A disease unique to carps. The pathogen is Gram-negative double bacilli. Symptoms: Prominent eyes, red and yellowish pus in the affected side of the body, and white bulge in the necrotic area. The prevention and control method is to sulfa drugs.