How to raise osmanthus fish

From 65438 to 0987, the culture of osmanthus fish began in the South China Sea. Up to now, it can be said that the breeding area has been expanding and the breeding level has been improving. It reflects consumers' welcome and love for osmanthus fish, reflects the good economic benefits of osmanthus fish culture, and conforms to market rules.

First, create a good breeding ecological environment.

1, pond conditions

Water source, water quality, soil quality and surrounding environmental conditions should meet the requirements of pollution-free farming. Pond area and water depth: 4-8 mu, water depth 2-2.5 meters, with minimum sludge.

2. Strictly clean and disinfect the pond.

One of the key techniques for raising osmanthus fish is strict cleaning and disinfection of ponds. Cleaning and disinfection of the pond should be carried out 8- 10 days after breeding "baitfish" and osmanthus fragrans in Tang Qian, and it is best to advance about half a month if possible. After cleaning and disinfection, the bottom of the pond can be exposed to the sun. Disinfectants for pond cleaning include quicklime, bleaching powder, chlorine dioxide, sodium dichloroisocyanurate, trichloroisocyanuric acid, dichlorohydantoin, bromochlorohydantoin and tea residue. It is suggested to use 20kg quicklime+1 bag/mu in the pond cleaning at the beginning of the year.

① quicklime: freshly baked or well-preserved ash blocks need to be cleaned by dry method, and the dosage per mu is 125- 150kg. The pond cleaning effect of quicklime disappeared for 7- 10 days.

② Tea residue: Wash the tea residue with water. Tea residue is crushed and soaked for 6- 12 hours, then mixed with water and sprinkled all over the pond. Tea cake has no sterilization and disinfection effect, so it should be used with sterilization and disinfection drugs. 40-45 kg of tea residue per mu of water surface and 0/3.5 kg of bleaching powder/kloc-,or 2500 g of trichloroisocyanuric acid or 300 g of dibromohydantoin.

Second, raise healthy and high-quality fish with appropriate specifications.

1, the standard of healthy and high-quality osmanthus fry:

① Non-inbred seedlings; One-ripe or two-ripe seedlings in that year;

② The specifications of seedlings in the same batch and pool are neat and consistent;

3 satiety;

④ The body is wide, with large and obvious stripes on the side, and the body color is bright and harmless;

⑤ In the natural state, it is clustered underwater and in droves; In addition to preying, it does not swim to the surface, rarely moves, and stands still underwater; At rest, the head is slightly tilted downward and the tail handle is bent. If it is picked up in a basin, it will move lively at first, then it will be still and will not lie on its side at the bottom of the pool;

⑥ The deformity rate is less than 3%.

2. Appropriate inventory specifications

It is most suitable to buy 2.5-3.5cm sweet-scented osmanthus seedlings. This kind of sweet-scented osmanthus seedlings can be directly raised in the pond, or can be thick, with high cost performance, convenient transportation, low transportation cost and high survival rate. Bought back 2.5-3.5cm osmanthus species should be cultivated in the pond after the standard thickness is about 10cm or 40-50g.

2.5-3.5cm osmanthus fragrans seedlings are cultivated to 10- 12cm, the cultivation density is 6000-8000 plants/mu, and the cultivation time is 25-30 days.

2.5-3.5 cm to 40-50g, the culture density is 4000-5000 strips/mu, and the culture time is 40-50 days.

Technical points:

① Cultivate enough palatable bait fish before osmanthus seedlings go down to the pond, and strictly disinfect and kill the pond water and bait fish. Insecticides should be carried out 1-2 days before stocking osmanthus fragrans seedlings, and each set of ginger+cellulose should be sprayed 1 day in advance or on the day of sowing, so as to disinfect and kill insects and reduce stress reaction.

② Timely supplement palatable feed fish. The size of feed fish should be small under the premise of palatability, and it is appropriate to eat it for about 5 days at a time. Before each feeding, the fed fish must be disinfected and killed by drug immersion bath.

(3) When the culture standard reaches the predetermined specifications, fish in the pond in the cool morning.

(4) The fish species passed the Tang Qian sorting standard, and the weak and deformed individuals were eliminated. The dosage of 1 mu/ mould package and ginger spraying can be used to reduce the complications of secondary infection.

3, fish stocking time

The stocking time of fish species affects the growth rate, feed coefficient (production cost), disease frequency and market price of osmanthus fish. The stocking time is directly proportional to the growth rate and inversely proportional to the feed coefficient. Early sowing has fast growth rate and low feed coefficient. Usually, the seeds released before May grow very fast and the feed coefficient is low (between 3.5 and 4.5). After the middle of July, the released seeds grew slowly and the feed coefficient was high (5-8). The main reasons for this phenomenon are: (1) climate and water temperature conditions; (2) Germplasm factors of seedlings.

The third is the reasonable stocking density of adult fish and the fish suitable for feeding.

The stocking density of osmanthus fragrans is very flexible, and the stocking density of adult osmanthus fragrans should be 1.200- 1.500 fish/mu (refers to the large-sized fish with the thickness after culture, if the fish with the size of 2.5-3.5cm is stocked, the stocking density will be increased by about 20%, that is,1.500-). The main cultured osmanthus fish in the pond should be matched with bighead carp and crucian carp. And the requirements for fish culture are great, with bighead carp 200-500g/tail and 20-30/mu; Carassius auratus 40-50g/ tail, 100- 150/ mu.

Four, feeding management technology

1, feeding technology

Types of feed fish In order to make osmanthus fish eat balanced nutrition, a variety of feed fish should be fed. In Guangdong, herring, southern crucian carp and herring are all good feed fish, and silver carp, bighead carp, crucian carp and bighead carp are all suitable for feeding osmanthus fish.

② The specifications of feed fish are based on palatability. On the premise of palatability, the specifications should be slightly smaller but not larger, so that individuals of different sizes can eat them. The developed products have neat specifications and high commodity value.

(3) Feed the feed fish in time, and there should be no disjointed feeding in the middle, otherwise it will cause diseases, especially gastrointestinal diseases, due to the impermanence of hunger.

(4) Feeding a small amount for many times, usually once every 5-7 days. In winter and early spring, the water temperature is low and the intake of osmanthus fish is low. It is advisable to take 7- 10 days each time.

⑤ Before feeding feed fish, feed fish must be disinfected and killed by drug immersion bath to prevent pathogens from being brought in by feed fish and cut off the transmission route of pathogens. Feed fish are disinfected and killed by the following methods: killing 50ppm with cellulose and soaking for 10- 15 minutes; Or soak in 3% ginger for 3-5 minutes.

Feed fish suffering from diseases such as sporozoosis, enteritis and hemorrhagic disease. It is not allowed to feed osmanthus fish, and the feed fish purchased from abroad must be cautious to prevent diseases caused by purchasing surplus feed fish in the sick pond.

2. Water quality management Water quality management is one of the key technologies for raising osmanthus fish.

① The pond with osmanthus fish is moderately fat. The growth rate of poor water quality is slow and diseases are frequent. Overfertilized water is rich in organic matter and oxygen consumption factors, and the water quality is easy to deteriorate. The water body with medium fertility has high plankton content, high oxygen production by photosynthesis and rich dissolved oxygen; When there are many microorganisms, the beneficial bacteria are often dominant, which inhibits the reproduction of diseased microorganisms, so there is little disease. In addition, the water with medium fat water is opaque, which is suitable for osmanthus fish to inhabit and has a sense of security. Medium fat water is transparent, the transparency is about 30cm, and the water quality is refreshing and oily green.

If the water quality is too fat, it is advisable to pump out some old water and replenish some new water. However, it is not advisable to change too much water at one time. Generally, a water level of about 30cm is appropriate. If the primary water quantity is too large, the water environment in the pond will change dramatically, which will cause stress reaction of osmanthus fish and cause diseases.

② Dissolved oxygen is the most important water quality factor, and ensuring rich dissolved oxygen in pond water is an important water quality management content. Osmanthus fragrans is a kind of benthic fish with high oxygen consumption rate and weak hypoxia tolerance, so it is necessary to use an aerator in the pond to raise Osmanthus fragrans. The standard for pond equipped with aerator is 0.4-0.5 kW/mu impeller aerator. Dissolved oxygen in the pool should be kept above 4.5mg/L, and not less than 3mg/L at the lowest. If it is lower than 2mg/L, "floating head" will appear. Generally, the startup time is from around midnight to the day after the sun comes out, and the noon is 10- 12 hours. If the weather is bad, you should start it earlier and extend the start time. Oxygen not only affects fish's breathing and life safety, but also affects fish's water quality factors such as ingestion, digestion, absorption, growth and development. When the dissolved oxygen in the water is rich, the fish eat more, the utilization rate of digestion and absorption is high, the growth rate is fast and the feed coefficient is low. In the case of oxygen enrichment, many harmful poisons are oxidized. For example, when dissolved oxygen is abundant, hydrogen sulfide in water cannot be produced and accumulated. When dissolved oxygen is sufficient, beneficial aerobic bacteria have strong reproductive ability, accelerate the decomposition of macromolecular organic substances and harmful poisons, and accelerate the material circulation ability of the pond, thus improving the productivity of the fish pond.

It is better for osmanthus fish to be equipped with a generator set and prepare some chemical oxidants, such as calcium peroxide [CaO2], sodium perborate [NabO3 4h2o] and sodium percarbonate [2naco3 3h2o2], in case of emergency.

(3) Eliminate and control harmful and toxic substances in pond water. Osmanthus fragrans has a high feeding density, a large appetite and a lot of excrement. Especially in the middle and late period of food intake, metabolic excreta is decomposed by bacteria to produce a large number of harmful and toxic substances such as nitrite [NO2- 1-N], ammonia nitrogen [NH3-N], methane [CH4], hydrogen sulfide [H2S], and the organic oxygen consumption is also large, which affects the food intake and H2S of osmanthus fragrans. Red-billed ophthalmopathy induced by water quality deterioration is an obvious example.

At present, microbial agents have been widely used in the control and improvement of pond water quality, such as nitrosamines, algae, nitrifying bacteria, photosynthetic bacteria, EM bacteria and so on. The so-called microbial preparation, also known as microecological preparation, is made by screening out some beneficial bacteria and artificially cultivating them. Microbial agents are generally composed of many kinds of bacteria, but there are also a single kind of bacteria. There are four main functions of microbial agents: first, microbial agents multiply in pond water and sediment after application, and inhibit the growth of disease microorganisms; Second, the bacteria in the microbial preparation decompose harmful toxic substances and macromolecular organic substances in the pond water and sediment, decompose harmful toxic substances into harmless and nontoxic substances, and decompose macromolecular organic substances into small molecular inorganic nutrients, thus accelerating the material circulation in the pond; Thirdly, photosynthetic bacteria, especially photosynthetic pigments, can carry out photosynthesis under anaerobic and light conditions, and use solar energy to obtain energy, but do not produce oxygen. In aquaculture water, hydrogen sulfide or small molecular organic matter can be used as hydrogen donor, at the same time, small molecular organic matter can be used as nitrogen source, and ammonium salt and amino acid can be used as nitrogen source, which can eliminate harmful substances such as ammonia nitrogen, hydrogen sulfide and organic acid and reduce oxygen consumption of water body. Fourthly, mixing microbial agents with feed, feeding or spraying them on crop leaves can promote the digestion and absorption of feed by raised animals and promote plant growth. Microbial preparations are generally applied once every half month, and once a month when the water temperature is low in winter. Microbial preparations cannot be used together with antibiotics and sterilization drugs, otherwise the bacteria in microbial preparations will be killed and will not work.

Use drugs to regulate and control water quality. Nuo Min+algae 3 mu/bag, applied in the morning, once every half a month. Zeolite powder is 20-25kg/ mu, which is used to adsorb heavy metal ions and other harmful poisons. Polyaluminum chloride can also purify water, and the dosage is 5-7 kg/mu. M, stirred with water and splashed all over the pool. Alum has the function of coagulation and precipitation, which can make dissolved and suspended organic and inorganic particles coagulate and precipitate, make water clear, eliminate ammonia nitrogen and nitrite, and reduce the pH value of water. When the water quality of source water is poor or changing water may lead to diseases and infections, closed culture without changing water and treatment of water quality with drugs have very obvious effects.

④ When the temperature is high in summer, raising the water level in the pond as much as possible can effectively reduce the occurrence of diseases; In winter, the water level in the pond should also be appropriately deepened to help osmanthus fish overwinter safely and prevent frostbite.