Culture skills of Pelteobagrus fulvidraco in four key periods

Pelteobagrus fulvidraco culture in lakes, reservoirs, ponds, rivers and other water bodies can make effective use of water bodies and obtain higher economic benefits. it is an effective way for farmers to adjust their planting and culture structure and increase their income. However, due to the miscellaneous feeding habits of Pelteobagrus fulvidraco, it is difficult to cultivate parent fish, and it is a scale-free fish, so there are different requirements for feed and culture management in different growth stages. in order to achieve high yield and high efficiency, we must master the culture skills of four key periods.

I. the period of parent fish cultivation

1. The collection of parent fish as parent fish requires its bright color, plump figure, strong physique, disease-free and injury-free, aged more than 2 winter age, male above 14.8cm, female above 11.7cm, and the ratio of female to male is 1 ∶ 1.50. when selecting male and female parent fish, pay attention to reasonable identification, the best time to collect parent fish is in the winter of the previous year.

two。 Parent fish collected by parent fish cultivation can be sterilized by 2% to 3% salt water for 10 to 15 minutes and then put into a special pond for cultivation. The area of the pond is more than 2 mu, and the water depth should be about 1.5m, which requires that the bottom of the pond is flat, the water quality has a certain degree of fertility, and the transparency of the pond water is about 30cm. Plants such as gathering grass and verticillium verticillata can be planted in the pond to provide bait organisms and habitats for parent fish, and some green shrimp can also be cultured to make full use of the water body and provide bait organisms for Pelteobagrus fulvidraco. During the breeding period of parent fish, you can feed small fish, shrimp or ground snails, clams, etc., or feed eel feed with snails, clams and other animal bait. In the process of parent fish culture, flush once every 2 to 3 days to promote the gonadal development of parent fish.

II. Fish fry cultivation period

Pelteobagrus fulvidraco fry can meet the summer flower specification of body length 2cm~3cm after 20 ~ 30 days in the breeding pond. In the period of fish fry cultivation, the pond area is 1 mu ~ 2 mu, the water depth is about 1 m, pH7~8, dissolved oxygen is above 5mg/L, and the pond water is required to be strictly disinfected. Rotifer, nauplius or small cladocera are the best palatable food organisms for fish fry in the first pond, so the fry should be sprinkled with manure 150kg/ mu ~ 300kg/ mu before entering the pond. When the fry reaches the body length 0.9cm~1.0cm, it can be fed with a small amount of compound feed twice a day, accounting for 3%-5% of the total body weight of the fish, but timely fertilization is required to ensure that the fry always have plenty of palatable food organisms.

III. Fish fingerling cultivation period

Fish fingerling cultivation is a large size fish species which can grow summer flowers about 2cm in body length to 5cm~6cm in body length. It is required that the area of the cultivation pond is more than 2 mu, the water source is sufficient, the water quality is good, and the stocking density is 10 tails / square meter ~ 15 tails / square meter. In the process of cultivation, first, it is necessary to feed scientifically, because Pelteobagrus fulvidraco has the habit of feeding in groups, so we should set up a feed table in the pond and put the feed on the feed table, feeding 2 to 3 times a day, the daily feeding amount is about 5% of the total body weight of the fish, and the content of crude protein in the feed is more than 40%. The second is to transfer water timely, regularly add water, change water, and apply fertilizer reasonably to ensure fresh water quality, sufficient dissolved oxygen, abundant bait organisms, and, if necessary, open an aerator to increase oxygen; the third is to disinfect regularly and disinfect the feed table with quicklime or bleach every half a month. Antibiotics and other drugs can also be added to the feed to ensure the survival rate of fish.

1. Pond main culture

The main results are as follows: (1) the pond chooses a scattered small pond with an area of 2 mu ~ 5 mu, which requires sufficient water source, and the water quality meets the standard of aquaculture water. The pond is easy to enter and drain, and the bottom of the pond is flat, which can ensure the depth of 1.5m~2.0m. At the same time, sandy soil is the best in the bottom of the pond, and the bottom silt is controlled around 10cm, and the water and fertilizer conservation is good. Finally, each pond must be equipped with mechanical equipment such as aerators and pumps.

(2) Disinfection and fertilization before seedling stocking, both new and old ponds must be cleaned and disinfected. The old pond should remove too much silt, keep only 10cm, and clean the pond with 150kg/ mu of quicklime dry method to thoroughly kill parasites, pathogens and wild fish. After one week of drying, the water storage reaches 80cm depth, and the inlet should be filtered with 30 mesh sieve silk to prevent wild miscellaneous fish and fish eggs from entering. Apply fermented organic manure fertilizer and water, the dosage is 150kg/ mu ~ 200kg/ mu, wait until there are a large number of zooplankton in the pond water before releasing fish species.

(3) large-size commercial fish are popular in the market, so large-size fish with about 30g/ tail should be put into adult fish breeding. The stocking quantity of fish species can be flexibly controlled according to pond conditions, management level, feed supply and fish species specifications. The general specification is that the stocking density of 30g/-tailed yellow carp is about 1500 / mu, and can be matched with 200 silver carp with 50g/ tail. The stocked fish species are required to be neat in specification, bright in color, smooth in body surface, disease-free and injury-free, fin-free and physically strong, and should be soaked in 5% salt water for 10 minutes before entering the pond. The species of Pelteobagrus fulvidraco are generally released in late April every year, and the silver carp species should be released half a month after the fish enters the pond to facilitate the growth of Pelteobagrus fulvidraco.

(4) the food fed to Pelteobagrus fulvidraco in natural waters is mainly small fish and shrimp, fish eggs and some aquatic insects, aquatic plants, etc. Artificial culture can be fed with fresh animal bait, such as small fish and shrimp, livestock and poultry processing leftovers, etc. Bean cake, peanut cake, wheat bran and so on can also be fed. Generally, compound feed is used for domestication and feeding, and the feed is made of imported fish meal, meat and bone meal, blood meal, soybean meal, rapeseed meal, dried fish and insect, etc., and the protein content is more than 35%-45% in the early stage of culture. the crude fat content is 5%-8%; small miscellaneous fish can be used to replace some imported fish meal in the later stage of culture, with a protein content of 30% and a fat content of about 6%. The reference formula is: fish meal 25%, bean cake 20%, vegetable cake 30%, @ # @ 245 powder 20%, corn meal 3%, minerals 2%, vitamins 0.2%.

(5) to adjust the water quality in order to prevent the aging of the water body, water was injected once a month in May and June, and the fresh water was changed once a month from 30cm to June to September. The water was changed about 15cm every time, and the water depth was kept at 1.2m~1.5m. At the same time, insist on regular disinfection and sprinkle the whole pool with 15ppm quicklime once a month to purify and disinfect the water quality. The aerator is used scientifically according to the determination of dissolved oxygen and the weather and water quality to keep the dissolved oxygen above 3mg/L.

(6) Pelteobagrus fulvidraco has strong disease resistance, as long as the water quality is controlled strictly in accordance with the requirements and routine disinfection and prevention are done, diseases rarely occur. Once the disease occurs, it is necessary to make timely and accurate diagnosis and accurate drug treatment. As Pelteobagrus fulvidraco is a scaleless fish, its tolerance to common drugs is not as strong as that of domestic fish, so it is necessary to give priority to prevention and use efficient and low-toxic drugs as far as possible. It is recommended that regular bait be given as a means of prevention, and monthly use of oxytetracycline and traditional Chinese medicine such as rhubarb and Radix Isatidis with an addition of 0.1% to 0.4% for 3 to 5 days. Try to avoid fish injury in fishing, stocking and transportation, so as to prevent fish from being infected with water mold in early spring, autumn and winter.

two。 When there is no special feed for Pelteobagrus fulvidraco and sufficient supply of small miscellaneous fish and shrimp in ponds, winter slices of Pelteobagrus fulvidraco can be cultured in ponds with a stocking density of 80 / mu ~ 150ind / mu. After 5 ~ 6 months of culture, the winter slices of about 15g/ can grow to 100g/ and produce about 10kg per mu of Pelteobagrus fulvidraco.

3. Cage culture

(1) the first condition of culture is the elaborate production of cages. The cage is made of polyethylene, the mesh of the net is generally required in 2.0cm~3.0cm, the mesh at the bottom of the net is 1.5cm, the specification of the cage is 12 square meters ~ 24 square meters, the shape of the cage is square or rectangular, the depth of the box is 2.0m; the second is to place the cage reasonably. The water quality of the water area set up by the cage requires live, cool and high dissolved oxygen. Put the cage into the water one week before fish stocking to make the cage wall adhere to algae and reduce fish body abrasions. The cage spacing is 2m~3m, and sunshade covers should be added above the cage in areas with strong sunshine. Third, pay attention to the water quality of the source, which requires that the water source is sufficient, stable and free of any pollution, the water depth of the cage is more than 2.5m, and maintain good water quality, the transparency of the water body is above 30cm, and the water exchange capacity is not large.

(2) the first is that the source of fish breeding must be a regular breeding farm, with neat specifications, bright color, no damage to the body surface, strong physique, lively swimming, excellent and pure fish, and it is best to use artificially propagated fish; second, the release time of Pelteobagrus fulvidraco in cage culture generally begins to release fish fry before and after the Spring Festival, and the fish fry should be washed with 5% salt water before entering the box. Third, the stocking density is generally 100 tails / square meter ~ 150 tails / square meter. In addition, some blunt snout bream and fine scale oblique jaw can be properly raised to make full use of bait organisms and purify the water quality of the cage.

(3) first, the feed must be fresh, mildew-free and rancidity-free, and it is best to choose the full-price feed produced by regular manufacturers, and the feed had better be powdery, and the feed should be adjusted into paste and put on the feed table of the cage; second, to do a good job of domestication and feeding, manual domestication and feeding will be adopted 2 days after the seedlings are put into the box, and can be fed normally after 5 ~ 7 days of patient domestication. Third, reasonable feeding, feeding 2 ~ 3 times a day, the amount of feeding is 3% or 5% of the total body weight of the fish.

(4) the daily management is to standardize the operation, regularly check the growth of the fish, carefully observe and analyze the fish situation, deal with the problems in time, make a good log of cage culture, and record the daily water temperature, feeding, feeding, dead fish and diseases, in order to accumulate experience; second, regularly scrub the dirt and algae on the cage, so that the water body can be fully exchanged. Third, often check the cage and find that it is damaged and repaired in time to avoid escaping fish or ferocious fish into the box; fourth, with the fluctuation of the water level of the reservoir, the cage must be adjusted to a suitable position of water depth in time; fifth, according to the market situation and the growth of fish, timely rotation of catch and release, as far as possible to give play to the best economic benefits. Cage culture of Pelteobagrus fulvidraco generally began to catch in batches in early August.