The Guangxi Aquatic Breeding Breeding Center has been introduced into the Apium Aquaculture Research Center of the Chinese Academy of Fishery Sciences since 2003. After years of breeding and promotion at the center, AOpen has become a favorite among farmers. In order to satisfy farmers' needs for Jianjian seedlings, and to extend the production season and regularly raise seedlings, in a few years of seed breeding, we constantly explored and innovated, summing up a set of ponds combined with industrial plants and ponds to cultivate broodstock. The in-house tanks are used for efficient human reproduction techniques for inducing hatching. The method is reported below.
First, materials and methods
1. material
(1) Broodstock pond cultivation Broiler broodstock is bred with two large fish ponds, and 4.5 hectares of male fish ponds are used to cultivate 300 male winter males, 4.5 hectares of female fish ponds are used to cultivate 300 female fish, and winter peanut cakes and bean cakes are used. Such as intensive cultivation, gonad maturation when the male is 2 ~ 4 kg / tail, female fish is 3 ~ 5 kg / tail.
(2) Spawning hatchery pool Spawning and hatching pool selection center The industrialized plant nursery pond has been put into use. It is a brick-concrete structure, and the bottom of the pool is covered with ceramic tiles, and is surrounded by paint. Each of the four small ponds forms a field font. There are a total of small ponds. 8 groups. Each tank is 4.6 meters high and 2.2 meters high and 0.8 meters high. Each pair of pools is drilled and nailed on opposite sides of the pool. Each side is 6 and 6 layers of nylon rope are pulled from the pool surface. Six air stones are fixed on each rope and all the pools are supplied with a 1.5-kilowatt blower.
(3) Auxiliary tools for oxytocin injection, two for long-handle fishing, two for short sea fishing, one set for water spray pipe, six-point 0.8 meter X6. On polyethylene nets or other waste polyethylene nets. The drainage pipe is 2 meters long and 5 centimeters in diameter. Put one end into a plastic basket with a mesh opening, 0.28 meters in diameter, and 0.28 meters in height. Put a small stone in the basket and wrap it in a 80 mesh polyethylene mesh bag.
(4) Oxytocinergic hormone is an oxytocin for high-efficiency fish for injection. In February and March, the use dose was 25 kg/10,000 active units for females and 50 kg/10,000 units for males; the temperature was higher in May and June, and the gonad maturation of broodstock was poor. The use dose was 20 kg/million for females. Unit, male 40 kg/10,000 units of activity. Pectoral fin injections are used to induce labor.
(5) Incubation water is used for pumping deep groundwater, the water quality meets the aquaculture water standard, and the well water temperature does not change with the season and remains at 23. C around.
2. method
(1) In the afternoon of moving the fish to hatch, the selected broodstock will be moved back to the workshop pool. The male and female are separated, and the appropriate amount of flushing water is used to stimulate and inflate the blower.
(2) Spawning ponds are provided with a 0.2-o. 3. a. Use a rope to tie the sides more than one point, and hang the polyethylene collection net on the nylon rope so that it hangs vertically in the pool. Three polyethylene gathering nets or a number of other waste polyethylene nets are hung in each pool, which are appropriately increased or decreased according to the density. When in use, the water is injected from one side of the pool and the other side is drained. The drain can adjust the water level in the pool. Inflate while changing the water.
(3) The oxytocin production and spawning time is 8-9 p.m. and the maximum number of fish per group is 6 groups. About 3 o'clock in the morning began to rear-end, this time appropriate to increase the amount of water spray, about 6 o'clock in the morning, spawning into the peak period, when the egg density on the egg collection network is very high, you can collect, side shop a new set of eggs.
(4) Incubation and management The collected meshes are moved to other pools, spread out and fixed to the nylon string on the pool surface with ropes to prevent the meshes from aggregating when inflated. Incubation pool mesh density should not be too high, each pool of eggs is generally 800,000 to 1 million. Before noon, the basic production of broodstock was completed. At this time, the water level in the spawning pool was reduced, and the long fish was used to operate on the pool. The broodstock was removed and the pond was cultivated. Spawning ponds have a lot of eggs sticking to the bottom of the pool and the wall of the pool, and the water level during incubation is controlled at 20-30 cm. Incubation pool changes the amount of water for 3 to 5 hours for the entire pool of water. During the incubation period, care should be taken to prevent the mesh from sticking out of the water. Attention should be paid to the adjustment of the amount of inflated air and the amount of water in the water to control the water level. After the hatching of the seedlings, the yolk is depleted and the fish is hunted for food. The mesh should be promptly removed and the egg yolk should be fed. The egg yolks were rubbed with 40 mesh nets and filtered in water for 4 meals/day. Observe each meal and observe adequate feeding. After 2 days of feeding, the fry ponds were routinely bred.
Second, the results from the Jian'ou breeding effect point of view, the spring maturity of females is good, each female has about 250,000 seedlings, hatching effect is ideal. The fertilization and hatching effects in summer are not ideal because the best maturation period of the broodstock has passed, and the persistent high temperature weather has a great influence on the gonads of the broodstock. The maturation of the female fish is not enough, and there is less male semen and the fertilization rate. Relatively low. The results are shown in Table 1.
Third, summary
1. One of the key prerequisites for the success of A. grandis breeding is the cultivation of broodstock in ponds. Winter broodstock should be separated from male and female and cultivated in deep pond after winter. The broodstock after spawning is kept in another pool and is not returned to the original pond. The original Jianshao broodstock breeding ponds were to remove debris from the pond and continue to cultivate immature broodstock. As the temperature rises, the water level of the pond is gradually deepened, and the deep water level is stored to 3 to 4 meters in the summer. The pond should be kept as low as possible to reduce irritation and cultivation should be continued. As long as the management is in place, broodstock can reproduce even in late summer and early autumn.
2. Another key factor in the success of the establishment of apiculture is the use of factory-plant water tanks for artificial oyster production and hatching. Factory production workshops have the following advantages:
(1) The temperature is constant, easy to hatch in different seasons, suitable for anti-season nursery. In the south, the gonad development of the broodstock that has been bred through the early spring has matured and can be bred by means of artificial oxytocin production, but the pond temperature is below 16 at this time. C. The temperature difference is large and the effect of spawning hatching is extremely poor. By the end of summer, the pond water temperature is 30-40. C. The gonads of broodstock that have not been produced have been partially absorbed. The gonads are not mature enough. The broodstock develop slowly at high temperatures and the hatching effect of ponds is poorer. However, in the factory workshops, deep well water is used, the water temperature is stable, and winter and spring 23 . C around, it is suitable for salmon hatching. In this way, Jianou can breed from the early spring to the late summer and early autumn, which greatly prolongs the time of reproduction compared to traditional squid breeding techniques.
(2) Less disease, high hatching rate and survival rate. Due to the use of deep well water, the water quality is fresh and pollution-free, and the amount of water exchanged is appropriate. There have been no diseases such as water mold.
(3) Flexible hatching, easy control of spawning and hatching of broodstock, reduced use of broodstock, improved fertilization rate and hatching rate, facilitated seed ordering arrangements and increased production efficiency.
(4) The egg-laying medium is directly sterilized with a good-quality polyethylene mesh sheet, which has good adhesiveness, simple drawing, simple operation, and small amount of labor, and is convenient for mass use.
(5) The cost of the opening of the splash flower is low, the body of the splendid flower is robust, and the survival rate after the pond is high. When waterflood feeds, it has a small area in a small pool, feeding more fully, uniform seedlings, can be fed according to the specific food intake of the seedlings, avoiding waste and reducing feeding costs.
After two consecutive days of adequate supply of egg yolks, the seedlings are stout and strong, and the outdoor ponds have been cultivated with good water quality. At this time, the survival rate is higher than that in the ponds.
3. Judging from practical experience, the artificial hatching of Jianou in the spring, summer and early autumn in the Nanning region is feasible. The cultivation of broodstock in ponds and the artificial production and incubation of pools in factory workshops can be further improved and promoted.
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