CATDOLL : CATDOLL: Can mandarin fish be raised in a pond area of ​​more than 30 mu?

1. Can mandarin fish be raised in a pond area of ​​more than 30 mu?

It is too big to be managed. Unless it is extensively raised, the yield is low.

2. How to use cement pond to breed commercial sweet-scented osmanthus fish

Breeding technology Parent fish selection and cultivation Mandarin fish likes flowing water to spawn. For artificial breeding, healthy and disease-free parent fish weighing 1 to 2 kg should be selected for breeding in a special pond. When feeding wild fish or commercial feed, artificial induction of labor can be performed, carp pituitary or HCG, LRH--A and other hormones can be injected, and the ovulation can be allowed to occur naturally. Mandarin fish eggs are slightly sticky, with a specific gravity greater than water, and are easy to sink to the bottom of the water. The flow rate should be increased when hatching in a loop, and should not be less than 0.2 meters per second. Fertilized eggs can hatch into fry after 3 to 4 days. More fry can be obtained by artificial insemination. Natural fry can also be caught for breeding. Cement pools are suitable for seedling cultivation, and the area should be several dozen square meters. The water quality should be fresh and there should be micro-flow. In addition, a small feed fry cultivation pool (other fish whose breeding period is basically synchronized with that of mandarin fish) should be attached to ensure the supply of live feed. Mandarin fish have the habit of the survival of the fittest. When there is a lack of feed, they will cannibalize each other, affecting the survival rate. Under the condition of sufficient feed, the fry can be raised for 10 to 15 days to grow into summer flower fish of about 3 cm. At this time, it can be transferred to adult fish breeding. The breeding method is mixed breeding in the adult fish pond and the other is to breed in the parent fish pond. Generally, about 3 cm mandarin fish are released around May. In the adult fish pond with more wild fish, 20 to 40 tails are released (the minimum size of the domestic fish released should be 1 times larger than that of mandarin fish), and 30 to 50 tails are released per mu of fish pond; more adult fish ponds with more tilapia and crucian carp can be released, 50 to 70 tails per mu; ponds with too many tilapias can release about 100 tails per mu. Ponds where mandarin fish are mixed should not be stocked with summer flower fish such as silver carp and bighead carp, because mandarin fish grow fast and will swallow small-sized domestic fish. Since mandarin fish consume more oxygen than domestic fish, the water quality of the pond where mandarin fish are mixed should not be too fertile, and new water should be injected at a regular period. Mandarin fish are sensitive to drugs. When applying drugs, the concentration should be calculated accurately. In the season with high water temperature, low dose or stop using drugs. Mandarin fish are raised in fish ponds, mainly using natural wild fish in the pond as feed, and some tilapia broodstock can also be raised to breed fry for food. Ponds near rivers and lakes with conditions can be filled with river fry and wild fish can be introduced as food. Mandarin fish can grow to commercial specifications of about 300 grams after 4 to 5 months of breeding, and 5 to 8 kilograms of mandarin fish can be produced per mu. Single breeding means breeding in a special pond. The pond area is about 1 mu, the water depth is 1.5 to 2 meters, the water quality must be fresh, and the water must maintain a slight flow. About 1,000 summer flower mandarin fish of about 3 cm are placed per mu, and wild fish such as tilapia, wheat ear fish, shrimp, or minced snails and clams are reasonably put in according to the fish inventory for mandarin fish to eat. Feeding amount is 3% to 5% of the total weight of the mandarin fish in the pond. Pond management and feeding technology ① Types of feed fish In order to make the sweet-scented osmanthus fish eat a balanced diet, a variety of feed fish should be fed. In Guangdong, dace, wheat ear carp, and wild dace are all very good feed fish. In addition, silver carp, bighead carp, crucian carp, and bream are all suitable as feed fish for sweet-scented osmanthus fish. ② Specifications of feed fish The standard for feed fish is palatability. Under the premise of palatability, the specifications should be slightly smaller rather than larger, so that sweet-scented osmanthus fish of different sizes can eat, and the specifications of the cultivated products are uniform and the commodity value is high. ③ Feeding feed fish should be timely, and there should be no interruption in feeding in the middle, otherwise it will cause diseases due to hunger and satiety, especially gastrointestinal diseases. ④ Feeding should be done in small amounts and multiple times, and it is generally appropriate to eat it all in 5 to 7 days. In winter and early spring, the water temperature is low, and the sweet-scented osmanthus fish eat less. It is appropriate to eat it all in 7 to 10 days each time. ⑤ Before feeding the feed fish, the feed fish must be disinfected and sterilized by drug immersion to prevent pathogens from being brought in by the feed fish and cut off the path of pathogen transmission. The following method is used to disinfect and sterilize the feed fish: soak in 100-150ppm (100-150ml/M3) formaldehyde solution for 10-15 minutes; or soak in 3% salt plus 8ppm (8g/M3) penicillin solution for 3-5 minutes. Feed fish with spores, enteritis, hemorrhagic diseases and other diseases must not be fed to sweet-scented osmanthus fish. The purchase of feed fish must be cautious to prevent the purchase of feed fish left over from the diseased pond and cause disease infection. Water quality management is one of the key technologies for raising sweet-scented osmanthus fish: ① The water quality of the pond for raising sweet-scented osmanthus fish is better with medium fertility. Thin water quality grows slowly and is prone to diseases. Over-fertilized water has more organic matter and oxygen-consuming factors, and the water quality is easy to deteriorate. Water with medium fertility has a large content of plankton, a large amount of oxygen produced by photosynthesis, and rich dissolved oxygen; there are many microorganisms, and beneficial populations are often dominant, which inhibits the reproduction of disease microorganisms, so there are fewer diseases. In addition, the transparency of water with medium fertility is not high, which is suitable for sweet-scented osmanthus fish to live in and feel safe. Water with medium fertility is specifically expressed by transparency, which is about 30cm. The water quality is refreshing and oily green. If the water quality is too fertile, it is advisable to extract some old water and add some new water, but the amount of water change each time should not be too much. Generally, the water level of about 30cm is suitable. If the amount of water change is too large at one time, the drastic change of the pond water environment will cause the sweet-scented osmanthus fish to have a stress response and cause diseases. ② Dissolved oxygen is the most important water quality factor. Ensuring that the pond water body is rich in dissolved oxygen is an important water quality management content. Sweet-scented osmanthus fish is a benthic fish with a high oxygen consumption rate and weak tolerance to low oxygen. It is essential to use an aerator in the pond for raising sweet-scented osmanthus fish. The standard for equipping aerators in sweet-scented osmanthus fish breeding ponds is an impeller aerator of 0.4~0.5KW/mu. The dissolved oxygen in the pool water should be kept above 4.5mg/L, and not less than 3mg/L during the lowest period. If it is less than 2mg/L, "floating head" will appear. The startup time is generally from around midnight to the next day after the sun comes out, and it should be started at 10-12 noon for 1.5-2 hours. If the weather is bad, it should be started earlier and the startup time should be extended.

3. The pond is the second year of raising mandarin fish, and it has not been disinfected. What should I do now?

As long as the water quality is good and there is no fish disease, it is okay not to disinfect. In the breeding process, EM bacteria, quicklime, etc. are often used to adjust the water quality, and water is changed when necessary, and there will be no problem.