In recent years, there has been an increase in the demand for commercial fish from the sea bream, and the demand for pod flowers has also increased. Although alfalfa blossoms naturally reproduce in flowing or still water, most of them are spawned sparingly due to environmental conditions, and fish eggs and fry are often swallowed by fish or other predators, resulting in a low survival rate. Artificial breeding can cause spawning of pupa spawns to concentrate spawning, increase the fertilization rate, hatching rate, and survival rate of fry, and achieve planned production. Artificial breeding techniques are described in detail as follows:
First, the choice of broodstock First, the brood brood broodstock must be purebred; followed by broodstock should be robust, plump and disease-free, no serious injuries; Third, the proportion of male and female should be appropriate, generally 1:1; fourth, female broodstock should 3rd to 4th ages above, weight 1.5 kg, male and female fish 2 in 3 years of age and above, weighing more than 1 kg; Fifth, it is best to store broodstock one year prior to hatching, do not temporarily collect during the spawning season, pond cultivation The broodstock is the best.
Second, broodstock breeding
1. The development of gonads and the amount of eggs laid by pods have a great relationship with the quality and quantity of bait used by the broodstock. Feeds for rearing broodstock must be diversified, and vegetal foods and animal foods should be taken into account to meet the needs of broodstock for various essential amino acids. Long-term feeding of single feeds must be avoided.
2. The mature process of gonadal development of the broodstock broodstock also requires a certain ecological environment. During the entire breeding process of broodstock, special attention must be paid to the regulation of water quality, and the oxygen level should always be ensured. Especially in the autumn, pool water is often accompanied by the tendency of aging. Always change the water and pay attention to maintaining a certain population of plankton in the water. To ensure the comfort of the broodstock environment, to maximize the accumulation of fish fat, to ensure the smooth production of eggs in the coming year.
3. The broodstock cultivation process should pay attention to the broodstock breeding in the previous year, because the broodstock has completed the growth phase of the egg cell in the winter, and it is only necessary to feed a small amount of refined baits in the spring to help the broodstock restore its physique. If the broodstock was not cultivated the previous year, the gonads were immature, or because the plumpness was low and the physique was thin, the effect of artificial reproduction would be very poor.
Third, spawning
1. The pond area is 0.2 mu - 1 mu, the water depth is about 1 meter, the bottom of the pool is less silt, the water injection and drainage are convenient, the environment is quiet, and the sunshine is sufficient. Before the pond is used, it is required to be disinfected by Qingchi. The water should be filtered strictly.
2. Fish nest production, set-up and management The materials for making fish nests include palm skins, aquatic plants, grasshoppers and artificial fibers. The fish nests are required to be dispersed as soon as they are filled with water. The ecological requirements for spawning are easy to use and must be sterilized before use. According to the number of spawning broodstocks, a corresponding number of fish nests are laid out, which are generally arranged at shallow water 1 meter away from the shore. The common arrangements are suspension-type and flat columns, with the best distribution in flat columns. Management of fish nests should pay attention to the following points: correctly estimate the time of spawning and put fish nests in time; nests should not be put in too much, generally 4 to 5 tufts per female are used; Replace, spawning should be promptly removed after 1 hour, and replace the new fish nest into the pool.
3. Aphrodisiac spawning measures can be used with high-efficiency fish oxytocin injection No. I or No. II aphrodisiac, the amount of female fish 0.5 ml / kg body weight, male and female 1/3-1/4 of the above dose can be.
IV. Incubation
1. Pond hatching There are two kinds of earth ponds and cement pools. The area of ​​the earthen pond is 0.5 mu - 1 mu, and the water depth is 1 meter. The concrete pool area is 20 - 50 square meters and the water depth is 50 - 80 cm. The hatching density is generally 3000 grains/m3 - 5000 grains/m3.
2. Drenching water incubation Drenching water incubation is to put the fish nest with fish eggs on the shelf in the indoor or plastic shed, and use artificial watering or water spray to keep the fish nest moist and control the proper temperature. The hatching hatch should pay attention to the following matters: The room temperature is controlled between 20°C and 25°C during the incubation period; often use a jug to pour water, evenly spread all the fish nests, keep the fish eggs moist, must not make it dry; indoor should maintain saturation Humidity, to properly grasp the incubation time, at any time to move the fish nest hatching hatch.
3. Incubation of defoaming water Incubation of defoaming water is the removal of viscous eggs from fertilized eggs after fertilization, and then hatching equipment is used to carry out water hatching. Detacking methods mainly include mud debonding method, talcum powder debonding method, and water debinding method.
V. Emergence
1. If the fish fry can be fed in parallel and the yolk sac disappears, they should be fed immediately.
2. Regulate the water quality. Always refill the new water, but the water temperature difference before and after changing the water must not exceed 3°C. Do not add water while feeding to prevent the top of the fry from eating.
3. Prevention and cure disease hot weather is easy to get bubble disease, pay attention to change the water. At the same time to clear frogs, dragonflies and aquatic insects.
First, the choice of broodstock First, the brood brood broodstock must be purebred; followed by broodstock should be robust, plump and disease-free, no serious injuries; Third, the proportion of male and female should be appropriate, generally 1:1; fourth, female broodstock should 3rd to 4th ages above, weight 1.5 kg, male and female fish 2 in 3 years of age and above, weighing more than 1 kg; Fifth, it is best to store broodstock one year prior to hatching, do not temporarily collect during the spawning season, pond cultivation The broodstock is the best.
Second, broodstock breeding
1. The development of gonads and the amount of eggs laid by pods have a great relationship with the quality and quantity of bait used by the broodstock. Feeds for rearing broodstock must be diversified, and vegetal foods and animal foods should be taken into account to meet the needs of broodstock for various essential amino acids. Long-term feeding of single feeds must be avoided.
2. The mature process of gonadal development of the broodstock broodstock also requires a certain ecological environment. During the entire breeding process of broodstock, special attention must be paid to the regulation of water quality, and the oxygen level should always be ensured. Especially in the autumn, pool water is often accompanied by the tendency of aging. Always change the water and pay attention to maintaining a certain population of plankton in the water. To ensure the comfort of the broodstock environment, to maximize the accumulation of fish fat, to ensure the smooth production of eggs in the coming year.
3. The broodstock cultivation process should pay attention to the broodstock breeding in the previous year, because the broodstock has completed the growth phase of the egg cell in the winter, and it is only necessary to feed a small amount of refined baits in the spring to help the broodstock restore its physique. If the broodstock was not cultivated the previous year, the gonads were immature, or because the plumpness was low and the physique was thin, the effect of artificial reproduction would be very poor.
Third, spawning
1. The pond area is 0.2 mu - 1 mu, the water depth is about 1 meter, the bottom of the pool is less silt, the water injection and drainage are convenient, the environment is quiet, and the sunshine is sufficient. Before the pond is used, it is required to be disinfected by Qingchi. The water should be filtered strictly.
2. Fish nest production, set-up and management The materials for making fish nests include palm skins, aquatic plants, grasshoppers and artificial fibers. The fish nests are required to be dispersed as soon as they are filled with water. The ecological requirements for spawning are easy to use and must be sterilized before use. According to the number of spawning broodstocks, a corresponding number of fish nests are laid out, which are generally arranged at shallow water 1 meter away from the shore. The common arrangements are suspension-type and flat columns, with the best distribution in flat columns. Management of fish nests should pay attention to the following points: correctly estimate the time of spawning and put fish nests in time; nests should not be put in too much, generally 4 to 5 tufts per female are used; Replace, spawning should be promptly removed after 1 hour, and replace the new fish nest into the pool.
3. Aphrodisiac spawning measures can be used with high-efficiency fish oxytocin injection No. I or No. II aphrodisiac, the amount of female fish 0.5 ml / kg body weight, male and female 1/3-1/4 of the above dose can be.
IV. Incubation
1. Pond hatching There are two kinds of earth ponds and cement pools. The area of ​​the earthen pond is 0.5 mu - 1 mu, and the water depth is 1 meter. The concrete pool area is 20 - 50 square meters and the water depth is 50 - 80 cm. The hatching density is generally 3000 grains/m3 - 5000 grains/m3.
2. Drenching water incubation Drenching water incubation is to put the fish nest with fish eggs on the shelf in the indoor or plastic shed, and use artificial watering or water spray to keep the fish nest moist and control the proper temperature. The hatching hatch should pay attention to the following matters: The room temperature is controlled between 20°C and 25°C during the incubation period; often use a jug to pour water, evenly spread all the fish nests, keep the fish eggs moist, must not make it dry; indoor should maintain saturation Humidity, to properly grasp the incubation time, at any time to move the fish nest hatching hatch.
3. Incubation of defoaming water Incubation of defoaming water is the removal of viscous eggs from fertilized eggs after fertilization, and then hatching equipment is used to carry out water hatching. Detacking methods mainly include mud debonding method, talcum powder debonding method, and water debinding method.
V. Emergence
1. If the fish fry can be fed in parallel and the yolk sac disappears, they should be fed immediately.
2. Regulate the water quality. Always refill the new water, but the water temperature difference before and after changing the water must not exceed 3°C. Do not add water while feeding to prevent the top of the fry from eating.
3. Prevention and cure disease hot weather is easy to get bubble disease, pay attention to change the water. At the same time to clear frogs, dragonflies and aquatic insects.