Several key periods of Pelteobagrus fulvidraco culture

I. the period of parent fish cultivation

1. Parent fish collection

As a parent fish, it is required that its body color is bright and plump, strong, disease-free and injury-free, the age is more than 2 winter years old, the male individual is above 14.8cm, the female individual is above l1.7cm, and the ratio of female to male is 1.5. When selecting male and female parent fish, pay attention to reasonable identification. The best time to collect parent fish was in the winter of last year.

2. Parent fish culture

The collected parent fish can be sterilized by 2% to 3% salt water for 10 ~ 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 2-3 days to promote the gonadal development of parent fish.

II. Fish fry cultivation period

The fry of Pelteobagrus fulvidraco can meet the summer flower specification of body length 2~3cm after 20-30 days in the breeding pond. In the period of fish fry cultivation, the pond area is 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 of 50 ~ 300kg/ mu before entering the pond. When the fry reaches the body length 0.9~1.0cm, 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 cultivate summer flowers with about body length 2cm to reach body length 5~6cm. 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: 15 tails / m2.

In the process of cultivation, one is 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 cattle, and, if necessary, open an aerator to increase oxygen; the third is to disinfect regularly and disinfect the feed table with quicklime or bleach powder every half a month. Antibiotics and other drugs can also be added to the feed to ensure the survival rate of fish species.

IV. Adult fish culture period

1. Pond culture

(1) Pond selection

A scattered small pond with an area of 2 to 5 is selected, which requires an adequate source of water 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 guarantee the water depth of 1.5 to 2.0m. At the same time, it is required that the sediment of the pond is the best, the bottom silt is controlled around l0cm, and the water and fertilizer retention is good. Finally, each pond must be equipped with mechanical equipment such as aerators and pumps.

(2) Disinfection and fertilization

Both new and old ponds must be cleaned and sterilized before the seedlings are released. The old pond should remove too much silt, keep only l0cm, and clean the pond with l50kg/ mu of quicklime dry method to thoroughly kill cattle worms, 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 amount is l50~200kg/ mu, wait until there are a large number of zooplankton in the pond water before releasing fish species.

(3) stocking of fish species

Large-size commercial fish are popular in the market, so large-sized fish species about 30g/ 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 stocking density of fish fingerling with 30g/ tail is about 1500 fish / mu, and can be matched with 50g/ tail silver carp species / mu. The stocked fish are required to have neat specifications, bright color, smooth body surface, no disease, no injury, no defective fins and strong physique. They should be washed with 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) Feed feeding

The food of Pelteobagrus fulvidraco in natural waters is mainly small fish and shrimp, fish eggs and some aquatic insects, aquatic plants, etc., artificial culture can be raised with fresh animal bait, such as small fish and shrimp, scraps of livestock and poultry processing, and can also be fed with bean cake, peanut cake, wheat bran and so on. 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. the protein content in the early stage of culture is more than 35%-45 ‰. The crude fat content is 5%-8%; small miscellaneous fish can be used to replace part of the 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%, wheat meal 20%, corn meal 3%, minerals 2%, vitamins 0.2%.

(5) regulating water quality

In order to prevent the aging of the water body, the water was injected once a month in May and June, and the fresh water was changed once a month from June to September. The water was changed about l5cm every time, and the water depth was kept at 1.2-1.5 m. At the same time, insist on regular disinfection and sprinkle the whole pool with l-5ppm quicklime once a month to purify and disinfect the water.

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) Disease control

Pelteobagrus fulvidraco has strong disease resistance, as long as the water quality is controlled strictly in accordance with the requirements, routine disinfection and prevention are done, diseases are rarely occurred. Once the disease occurs, it is necessary to make timely and accurate diagnosis and accurate drug treatment.

As Pelteobagrus fulvidraco is scaleless fish, the tolerance to common drugs is not as good as domestic fish, so prevention should be abundant, and high-efficient and low-toxic drugs should be used as far as possible. It is recommended to take regular bait as a means of prevention, using oxytetracycline and traditional Chinese medicine such as rhubarb and Radix Isatidis every month with an addition of 0.1%-0.4% for 3-5 days. Try to avoid fish body injury in fishing, stocking and transportation, so as to prevent fish body from infecting water mold in early Chung, autumn and winter low temperature season.

2. Pond culture

Under the condition that there is no special feed for Pelteobagrus fulvidraco and there is no sufficient supply of bait organisms such as small miscellaneous fish and shrimp, the winter slices of yellow decadent fish can be cultured in the ponds where other fish are mainly cultured. the stocking density is 80,150 pieces / mu. After 5-6 months of culture, the winter slices of about 15g/ can grow to l00g/ and produce about 10kg per mu.

3. Cage culture

(1) Culture conditions

First, carefully crafted cages. The cage is made of polyethylene, the mesh of the net is generally required in 2.0~3.0cm, the mesh at the bottom of the net is 1.5cm, the specification of the cage is 12~24m2, the shape of the cage is square or rectangular, and the box depth is 2.0m.

Second, the platform manager placed the cage. The water quality of the cage is required to be alive, cool and high dissolved oxygen. Sink the cage into the water one week before fish stocking to make the cage wall adhere to algae and reduce fish abrasions. The distance between the cages is 2cm. Sunshade covers should be added above the cages in areas with strong sunshine.

Third, pay attention to the water quality of the source. The water source is required to be adequate, stable and free of any pollution, the water depth of the cage is required to be more than 2.5m, and the water quality is good, the transparency of the water body is above 30cm, and the water exchange capacity is not large.

(2) Fish stocking

First, the source of fish must be a regular seedling farm production, neat specifications, bright color, no damage to the body surface, strong physique, swimming lively, excellent and pure, it is best to use artificially propagated fish.

Second, the timing of cage culture of Pelteobagrus fulvidraco generally begins to release fish before and after the Spring Festival, and the fish needs to be washed with 5% salt water before the fish is put into the box.

Third, the stocking density is generally 100 million 50 tails / m2. 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) Feed feeding

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

(4) Daily management

The first 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 cage culture log, and record the daily water temperature, feeding, feeding, dead fish and diseases, so as to accumulate experience; the second is to often scrub the dirt on the cage and attach algae to make the water exchange fully; the third is to often check the cage and find damage and repair it in time to avoid escaping fish or ferocious fish into the cage. Fourth, with the fluctuation of the water level of the reservoir, it is necessary to timely adjust the cage to a suitable position of water depth; 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.

Pelteobagrus fulvidraco cultured in cages generally began to be caught and sold in batches in early August.