Rainbow trout is a cold-water fish that normally inhabits in the rapid-flowing waters with clear water and water temperature of 20°C. It is suitable for high-density intensive aquaculture in flow-through ponds, and it is rapidly fed with artificial compound feed for high yields. Rainbow trout is rich in nutrients, delicious meat, less muscle stab, high food value, and is one of the world's major aquaculture species. Rainbow trout seed artificial propagation techniques are described below.
First, the choice of broodstock broodstock selection of non-abnormal, good shape, bright colors, fast swimming, not slow, fast growth and response to external stimuli sensitive individuals as well, the general use of 3 to 7-year-old fish as broodstock.
Second, the bred fish breeding pond water flow rate, dissolved oxygen 6 mg / l, water temperature 5 °C ~ 13 °C, 1 to 3 fish stocking broodstock. Feed the easily digestible minced fish or other animal feed, and feed 0.5% to 2% of the fish's body weight. One month before the breeding period, the male and female segregation pools were reared. To stimulate the production of sperm when dividing the pool, males can be kept in the pool downstream of the female pond.
Third, the broodstock maturity test Fully mature female abdomen enlargement, red, swollen reproductive holes, external protrusion, both sides of the ovary droop outline, gently squeezing the abdomen, gonadotropin outflow of eggs. The high-quality eggs are red, orange or orange, and the eggs are round and plump with uniform size. Males generally have mature semen throughout the breeding season, and good quality semen is bright yellowish liquid. Bad semen contains more water and is blue. There are fewer sperm and poor vigor.
Fourth, egg fertilization first squeeze the eggs of the female fish in enamel pots or plastic pots, fish eggs immediately after the semen directly squeezed on the eggs of the semen, usually 10,000 eggs squeezed into about 5 ml ~ 10 ml Semen. Since the life time of sperm in the water is very short, care should be taken during operation not to mix water into the semen. After the fish eggs are squeezed on the semen, they are immediately stirred with feathers or hands so that the semen and the eggs are fully connected, and then a small amount of fresh water is added to continue stirring for 1 minute, and the eggs are rapidly fertilized. Stir for several minutes after stirring, continue to change the water and stir several times, place the rinsed eggs in the basin of fresh water for about 1 hour to 2 hours, wait for the eggs to absorb enough water and inflate, and then transfer them to the incubator for counting after hatching. .
5. Water conditions for hatching Water quality for hatching should be clarified. The pH should be 6.5 to 7.4, the water temperature should be 7°C to 13°C, and the dissolved oxygen in water should be 7.72 mg/L to 10.15 mg/L. Under these conditions, it can be 24 days to 50 days. Hatched larvae.
6. Disinfection The fertilized eggs must be sterilized regularly from the start of incubation. They can be disinfected with 2% sodium chloride solution or 0.5% formaldehyde solution for 30 minutes each time.
7. Remove dead eggs. Oval clips made of iron wire. Sort dead eggs (white ones) one by one. Operate them lightly to avoid stimulating vibrations.
VIII. Incubation of larvae There is a large yolk sac under the abdomen of the larvae, which is not fed at this time. If the larvae gather into a heap and the water flow is not good, it can easily cause death due to lack of oxygen. Therefore, the larvae in this stage should be placed in a fluent environment. The larvae can be transferred into small indoor cement shallow pools with about 10,000 per square meter. The water temperature is 10°C. The flow rate of the pool water is maintained at 20 liters/minute to 30 liters/minute per 100 thousand. After 20 days, the yolk sac of the larvae was reduced, and they began to feed and ate.
9. Feeding of juvenile larvae into the floating larvae continues to develop until the yolk sac is completely absorbed, and it enters the juvenile fishery stage. At this point, hatching work will end.
First, the choice of broodstock broodstock selection of non-abnormal, good shape, bright colors, fast swimming, not slow, fast growth and response to external stimuli sensitive individuals as well, the general use of 3 to 7-year-old fish as broodstock.
Second, the bred fish breeding pond water flow rate, dissolved oxygen 6 mg / l, water temperature 5 °C ~ 13 °C, 1 to 3 fish stocking broodstock. Feed the easily digestible minced fish or other animal feed, and feed 0.5% to 2% of the fish's body weight. One month before the breeding period, the male and female segregation pools were reared. To stimulate the production of sperm when dividing the pool, males can be kept in the pool downstream of the female pond.
Third, the broodstock maturity test Fully mature female abdomen enlargement, red, swollen reproductive holes, external protrusion, both sides of the ovary droop outline, gently squeezing the abdomen, gonadotropin outflow of eggs. The high-quality eggs are red, orange or orange, and the eggs are round and plump with uniform size. Males generally have mature semen throughout the breeding season, and good quality semen is bright yellowish liquid. Bad semen contains more water and is blue. There are fewer sperm and poor vigor.
Fourth, egg fertilization first squeeze the eggs of the female fish in enamel pots or plastic pots, fish eggs immediately after the semen directly squeezed on the eggs of the semen, usually 10,000 eggs squeezed into about 5 ml ~ 10 ml Semen. Since the life time of sperm in the water is very short, care should be taken during operation not to mix water into the semen. After the fish eggs are squeezed on the semen, they are immediately stirred with feathers or hands so that the semen and the eggs are fully connected, and then a small amount of fresh water is added to continue stirring for 1 minute, and the eggs are rapidly fertilized. Stir for several minutes after stirring, continue to change the water and stir several times, place the rinsed eggs in the basin of fresh water for about 1 hour to 2 hours, wait for the eggs to absorb enough water and inflate, and then transfer them to the incubator for counting after hatching. .
5. Water conditions for hatching Water quality for hatching should be clarified. The pH should be 6.5 to 7.4, the water temperature should be 7°C to 13°C, and the dissolved oxygen in water should be 7.72 mg/L to 10.15 mg/L. Under these conditions, it can be 24 days to 50 days. Hatched larvae.
6. Disinfection The fertilized eggs must be sterilized regularly from the start of incubation. They can be disinfected with 2% sodium chloride solution or 0.5% formaldehyde solution for 30 minutes each time.
7. Remove dead eggs. Oval clips made of iron wire. Sort dead eggs (white ones) one by one. Operate them lightly to avoid stimulating vibrations.
VIII. Incubation of larvae There is a large yolk sac under the abdomen of the larvae, which is not fed at this time. If the larvae gather into a heap and the water flow is not good, it can easily cause death due to lack of oxygen. Therefore, the larvae in this stage should be placed in a fluent environment. The larvae can be transferred into small indoor cement shallow pools with about 10,000 per square meter. The water temperature is 10°C. The flow rate of the pool water is maintained at 20 liters/minute to 30 liters/minute per 100 thousand. After 20 days, the yolk sac of the larvae was reduced, and they began to feed and ate.
9. Feeding of juvenile larvae into the floating larvae continues to develop until the yolk sac is completely absorbed, and it enters the juvenile fishery stage. At this point, hatching work will end.