I. Preparation for breeding conditions
1. Reserve broodstock selection and cultivation after the beginning of autumn selection 1 + ~ 3 + age, body characteristics in line with species standards, swimming posture correct, moderate fullness, good quality goldfish as a reserve broodstock, into the cement pool or set of pot culture. The non-reproductive seasonal sign of goldfish is not obvious, and the issue of male-male ratio is not taken into consideration temporarily.
The stock of selected stocking broodstock is stocked, and the area of ​​2 to 10 square meters of culture pool is good, which is convenient for proper activities of goldfish, which is not only conducive to health but also not falling out due to too many activities. Stocking density 5 to 10/m2. The culture pool should have convenient drainage and drainage conditions, store 25 to 40 centimeters (depending on the size of the fish), and be equipped with aeration and oxygenation equipment.
Reserve broodstock feed high-protein low-fat feeds 2 to 3 times a day, each feeding amount can not be too large, 8 to 10 minutes to eat clean prevail. It is advisable to feed buoyant pellet feed and animal live bait (such as leeches, red worms, etc.) on each meal in order to ensure that the gonads and body development of goldfish are met.
Keep the water fresh and lively. It is best to light green oil. When the water quality is too rich, adjust the water. If the water color is old (such as dark brown or dark green with suspended particles), you need to turn the pool or change the water. Drop it. Open the air pump to supplement the oxygen in the pond at night or in rainy weather.
2. Preparation of the spawning pool 1 to 5 square meters, a depth of 40 centimeters, a smooth cement pool, or pots can be used. After cleaning and disinfecting, 25 cm of water shall be stored 2 to 3 days before the broodstock enters the pool. Then the plastic film is covered on the pool to increase the water temperature, and is equipped with inflatable equipment.
Second, breeding will be cold in autumn and winter season, after the water temperature of the reserve broodstock drops to 15°C, cover the fish pond with plastic film or move the reserve broodstock into the indoor fish pond so that the water temperature will rise. When the water temperature rises above 20°C, it can be carried out. Breeding breeding. Water temperature reduction and recovery are the key to this technology. The cold stimulation is conducive to the synchronization of the goldfish gonorrhea to phase IV, and the temperature rise is a necessary condition for spawning.
1. The choice of broodstock. The requirements for the selection of broodstock are basically the same as those for broodstock, except that it is easier to distinguish between genders. The selected broodstock is transferred to the prepared spawning pond at a ratio of 1:1.5 to 2 males or females, or enters the pool after injecting oxytocin.
2. Inject drugs. Using 0.65% physiological saline as a solvent, administrate the oxytocin at a concentration of LRH-A 25 micrograms + HCG 500 units/ml, and then inject at a dose of 1 ml per female 250 grams of female fish. The male dose is halved. Take a one-time injection method from the base of the pectoral fin to the abdominal cavity. Secondary injection can also be used, then the first needle only injected LRH-A, 12 hours after the injection of HCG, the better.
3. After the broodstock is moved into the spawning pool, the fish nest for spawning should be placed immediately. The fish nest can be made of goldfish, water hyacinth, brown silk, willow root, and even wool or plastic ropes. The key is to disinfect it cleanly. Second, softness does not hurt the fish, the third must be finely branched, and the fourth must not be too loose.
Third, hatching
1. General goldfish broodstock estrus spawning after 12 to 24 hours after the injection of the drug, the water temperature above 22 °C, the female fish will produce complete mature fish eggs within 24 hours. Therefore, the fish nests should be inspected on the second day of production, and the attached broods should be removed immediately, soaked in a solution of 20 mg/l methylene blue for 15 minutes, and then transferred to hatching ponds for hatching.
2. The hatching tank should be indoor or covered with plastic film to ensure that the incubation water temperature is not lower than 20°C. It is better if it can reach 25°C. 5 to 10 square meters of cement pool to do hatching pool is better, because the hatching pool is also a fry culture pool, too small water temperature changes in water quality, easy to induce disease, too much space is too large, affecting the shape of goldfish. The hatchery should be disinfected in advance and stored 20 to 25 centimeters in advance for 2 to 3 days.
3. The fertilized eggs were hatched at a density of 1000 grains per square meter and hatched in each hatching pond, and depending on the growth and density of the eggs after about 10 days of emergence, the hatching was considered again. It can also be hatched at the density of 10,000 grains per square meter. After the fishermen swim for 3 to 5 days, they are carefully pulled up by the dense net.
Fourth, fry breeding fry during hatching, can be a small number of times into the hatchery pond into the fertilizer water, until the hatching of the fry two days after the absorption of the yolk is complete, start swimming horizontally, the fry can take in the water of small zooplankton such as rotifers, Paramecium When the fish fry begin to swim, 150 to 200 mesh zooplankton nets are used to fish zooplankton wild, and after filtering with a 100 mesh filter, the fry is fed under the filter (ie, smaller individual zooplankton). However, usually in the cold season, zooplankton harvested in the wild tend to be dominated by large individuals, and is not suitable for feeding freshly-opened fish. A more realistic approach is to first feed 5 to 7 days with egg yolk, and then feed the collected zooplankton or mini-fry feed.
When fry can feed on artificial feed, its cultivation method is not much different from that of spring-grown goldfish seedlings. The only difference is that we should pay attention to insulation and do not let the water temperature of the fry pool be lower than 15°C. Otherwise, the fry will survive even if it is alive, constitution and shape. It will also be greatly affected.
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