CATDOLL : CATDOLL: How about breeding mandarin fish?

At present, the breeding of mandarin fish can be divided into three stages: fry cultivation stage, fish fingerling cultivation stage and commercial mandarin fish breeding stage. The fry cultivation stage is about 3-20 days after hatching, and the fish grow into 3 cm summer flowers. This stage is completed in the seedling farm. The fish fingerling cultivation stage is to cultivate the 3 cm summer flowers into large-sized fish of about 6-8 cm, and the cultivation time is 7-15 days. This stage is the key to commercial mandarin fish breeding. In our area, earth pond cultivation and cage cultivation are commonly used.

1. Cultivation in earthen ponds

The pond area is generally about 1 mu, the water depth is 2 meters, and about 10,000 3 cm summer mandarin fish are stocked per mu.

(1) Feeding cultivation method: Feeding bait fish according to the daily food intake (or the number of fish ingested per day) of mandarin fish. In this cultivation method, the density of summer mandarin fish can be higher, and generally 12,000 fish are released per mu. Before stocking, the pond should be cleaned and disinfected with quicklime, and a filter mesh should be set up when the water is entering to prevent ferocious fish from entering. When summer mandarin fish are just put into the pond, the water level is shallow, preferably 60 cm. As the individual fish grows, the water level gradually increases to about 1.5 meters. When feeding bait fish, regular positioning should be achieved. When the mandarin fish fry are 3-6 cm long, 4-8 bait fish are fed per day, and the body length of the bait fish does not exceed 55-60% of the body length of the mandarin fish; after 6 cm, 4-5 bait fish are fed per day, and their body length does not exceed 50-55% of the body length of the mandarin fish. Seven days after the pond is filled, spray the entire pond with 0.7 PPM of copper sulfate and ferrous sulfate mixture (5:2) once to mainly prevent and control wheelworms and tricholoma.

(2) Intermediate breeding method: refers to the method of first cultivating suitable bait fish before stocking summer mandarin fish, and then stocking mandarin fish fry, so that mandarin fish and bait fish grow in the same pond. This breeding method generally stocks 8,000 to 10,000 3 cm mandarin fish per mu, and the stocking amount of bait fish is about 700,000 per mu, and the body length of bait fish is strictly controlled not to exceed 55-60% of the mandarin fish. This breeding method should pay attention to water quality management, with a water level of 60 cm at the initial stage of stocking, and water injection every 3 days after stocking, with a water injection volume of about 25 cm each time. Finally, the pond water is maintained at 1.5-1.8 meters. Disease prevention and control is the same as above.

2. Cage cultivation

The area of ​​the cage is 2-6 square meters, and its length, width and height are 2 meters × 1 meter × 1 meter or 2 meters × 2 meters × 1 meter or 3 meters × 2 meters × 1 meter. It is fixed with bamboo or wood in a pond with good water quality or an open pond. The cage mouth is 20-30 cm above the water surface. The cage material is a 40-mesh nylon mesh. The stocking density is generally 400-800 per square meter. After 7-15 days, it will be cultivated into a large-sized mandarin fish of 6-8 cm. In the cultivation management, it is necessary to wash and change the cage frequently to keep the water quality in the cage fresh and the dissolved oxygen sufficient. The method and quantity of feeding bait fish are the same as those of earth pond cultivation. Disease prevention can be carried out by immersion in 3PPM copper sulfate or 3% salt water. It should be immersed once every 2 days before 4.5 cm, and once every 3 days above 4.6 cm.

Whether cultivating mandarin fish in earthen ponds or cages, the following issues should be noted: (1) Mandarin fish summer flowers about 3 cm in length should be soaked in 3PPM copper sulfate or 3% salt water for 5-10 minutes. (2) Oxygenation equipment should be equipped during the cultivation process, and oxygen should be added immediately when floating heads are found. (3) Every morning and afternoon, the feeding, growth and growth of mandarin fish and the changes in bait fish should be checked regularly, and the number of bait fish and their specifications should be supplemented at any time.

Ongrowing techniques

Mandarin fish adult farming is to raise 3 cm mandarin fish fry or 6-8 cm fish fingerlings into commercial fish weighing about 500 grams. This process takes about 180 days. The length of the breeding time depends on whether the bait fish is sufficient and palatable, whether the water quality is good, and whether the management is proper. At present, the main breeding methods include pond breeding, mixed breeding in adult fish ponds (small reservoirs), and cage breeding.

1. The pond is mainly used to raise mandarin fish

(1) Pond conditions: The pond should have a hard bottom, little silt, be close to a water source, be easy to drain and irrigate, and have no domestic or industrial sewage flowing in. The area of ​​a pond without bait fish should not be too large, generally 1-3 mu. Under the condition of a pond equipped with bait fish, the area should be 2-5 mu. Before stocking, the pond should be cleaned and disinfected by conventional methods to kill various disease organisms and pathogens. After filling the water, 1-2 days before the mandarin fish fry are planted in the pond, use 0.7PPM copper sulfate and ferrous sulfate mixture (5:2) to spray the entire pond once to kill water parasites and improve the survival rate of mandarin fish (especially summer flowers).

(2) Disinfection of fish species and bait fish: The stocked mandarin fish species and temporary storage containers should be immersed in 3PPM copper sulfate solution, 3% salt water or 20PPM potassium permanganate solution for 5-10 minutes. The bait fish fed regularly should also be disinfected in this way to prevent pathogens from being brought into the breeding pond from the stocked fish species and bait fish.

(3) Stocking method: There are three commonly used stocking methods:

① Directly stock 3 cm mandarin fish fingerlings. The local mandarin fish summer flower is cultivated for one year and becomes a commercial fish. The Guangdong mandarin fish summer flower can be put on the market in the same year. The stocking density is about 2,000 per mu. The initial breeding method is the same as that of cultivating mandarin fish fingerlings in earthen ponds, and then feeding mainly with bait fish. This method is simple to work, saves labor and ponds, but due to the small size of the fish fingerlings, the survival rate is generally only 50%, and the control is poor.

② Stocking 6-8 cm large-sized mandarin fish fingerlings. This method is suitable for farmers with larger aquaculture scales, generally 1000-1200 fish per mu. The advantage is that the survival rate is high, generally 85-90%, and the production is highly controllable.

③ Release one-year-old mandarin fish fingerlings, with a size of 50-100 grams per fish, and release about 500 fish per mu. The stocking specifications are basically the same. About 200 silver carp and bighead carp, and about 200 old silver carp are raised per mu. It is not suitable to raise grass carp, black carp, carp, etc. Purchase small fish fingerlings in winter and temporarily raise them in ponds.

(4) Feeding method: The sources of feed fish for feeding mandarin fish include artificial breeding and wild fish collection. The requirements for bait fish are: 1. They must be alive; 2. They must be of a palatable size; 3. They must be free of hard spines; and 4. They must be supplied in a timely manner. The above requirements must be met as much as possible to achieve good results.

① As for the varieties of feed fish, any small fish, shrimp and loach without hard spines can be used as bait fish for mandarin fish. However, considering the source, economy and food preference, it is better to choose dace, crucian carp, silver carp and bream seedlings.

② The specifications of feed fish should be based on the different growth stages of mandarin fish. (See the table below)

Specifications of bait fish for mandarin fish farming

Body length of mandarin fish (cm)

3-14

15-20

21-25

26-30

31-35

Feed fish body length (cm)

1.5-5

3-6.5

4.5-7.5

6-9

7.5-15

③ The amount of feed fish fed: to grow a 3 cm mandarin fish (weight 0.5 g) into a commercial fish of about 500 g, the daily feed fish feeding amount starts from 70% of the body weight and gradually decreases to 8-10%, and the annual feed coefficient is about 4. When stocking a mandarin fish seed pond with 1 order, the daily feed fish feeding amount is gradually reduced from 8% to 5%, and sufficient feed fish is fed from the beginning of autumn to the white dew. The annual feed coefficient is about 5. The monthly feeding plan of feed fish can refer to the following table:

Monthly feeding plan for 1-year-old mandarin fish breeding feed fish

month

4

5

6

7

8

9

10

11

% of annual planned feeding amount

4

8

10

12

18

30

10

5

④ Feeding technology: According to the breeding method and scale, production indicators and harvest schedule, formulate the production and ordering plan of feed fish in advance, including the supply time, variety, specification and quantity; according to the growth needs of mandarin fish, feed fish are fed regularly, generally replenished every 3-5 days, so that the feed fish in the pond can always maintain a certain density to ensure that the mandarin fish can eat enough every day. Under the premise of not exceeding the carrying capacity of the pond, put as much feed fish as possible to let it consume and grow in the pond.

⑤ The production of feed fish: to grow one 500g mandarin fish, about 4,000-5,000 feed fish weighing 2-2.25kg are needed. To cultivate one mu of mandarin fish, 3-4 mu of feed fish are needed. The stocking density of feed fish is 1-2 times higher than that of conventional seedling cultivation. The method of high-density cultivation, gradual thinning, and phased feeding is adopted to ensure that the feed fish meet the requirements in terms of quantity and grow in size simultaneously.

⑥ Daily management: First, inspect the pond once in the morning and evening to check whether the fish have enough feed and feeding conditions and whether they float. If any floaters are found, rescue them in time. Second, check the transparency of the water body and keep it above 40 cm. Third, add and change water regularly to keep the water fresh. Fourth, apply quicklime regularly, 10 kg per mu each time, to adjust the pH of the water body.

2. Mixed culture of mandarin fish in fish ponds (small reservoirs)

Generally, 20-30 large-sized mandarin fish of about 6 cm or one ream of mandarin fish are placed per mu, and 100-200 old silver crucian carp are placed per mu (the seedlings produced by silver crucian carp are just the right feed for mandarin fish). This breeding method makes full use of the natural wild small fish in the pond. Generally, there is no need to feed bait fish specifically. It can produce about 10 kilograms of commercial mandarin fish per mu, which can improve the economic benefits of the pond. After the mandarin fish is raised in the pond, it should be noted that snakehead fish cannot be raised. When fish diseases occur, trichlorfon cannot be used for prevention and control, and water quality management should be further strengthened.

3. Cage culture of mandarin fish

(1) Location of cages: Reservoirs, lakes and rivers with fresh water quality and no pollution can be used to raise mandarin fish in cages. The water area where the cages are set up must be more than 40 cm transparent, more than 2.5 meters deep, and have a constant flow of water. The reservoir cannot be located in a bay, and there must be no submerged plants at the location where the cages are set up.

(2) Cage structure: The cage area is 5-20 square meters, made into a rectangular shape, 2 meters high, and is generally made of polyethylene. The mesh size is 1-2 cm and it is open. The cage is fixed around and at the four corners with bamboo and wooden stakes so that the cage is 30 cm above the water surface.

(3) Stocking size and density: For large-sized mandarin fish of about 8 cm in length, the stocking density is 20-25 per square meter; for one-year-old fish weighing about 50-100 grams, the stocking density is 15-20 per square meter.

(4) Time of entry: Large-sized mandarin fish should be entered into the box in early July if possible, and one-year-old mandarin fish should be entered into the box in March.

(5) Size and density of feed fish: The size of feed fish should match that of mandarin fish in cages, generally 5.5 cm or 5-7 g, with a stocking density of 800-1000 fish/m2. Feed fish are then released gradually in the same way as mandarin fish in ponds.

(6) Daily management:

① Adjust the water quality. Cage culture of mandarin fish should be equipped with oxygenation facilities or flushing equipment. When the weather is hot and humid or it is rainy continuously, the aerator should be turned on or the water should be flushed to increase oxygen.

②Inspect and clean the cages. Inspect the cages every morning, noon and evening, and clean them every 10-15 days to keep the cages in normal shape, ensure the water quality in the cages is fresh and smooth, and prevent the nets from breaking and escaping fish. ③Prevent floods, typhoons and storms. In seasons with frequent bad weather, pay attention to weather forecasts and do a good job in the safety and reinforcement of the cages in a timely manner.

④ Prevent fish diseases. Before the fish are put into the box, they should be soaked in 3-4% salt for 5-10 minutes. Usually, copper sulfate and ferrous sulfate (5:2) mixture or bleaching powder should be used in the net cage to prevent diseases. The medicine bag should be hung in the upwind. Wrap the net cage with plastic film every week, sprinkle salt water to make the concentration in the box 3-4%, and soak for 10 minutes. Feed fish should also be soaked in 4% salt water for 10 minutes before entering the box.

After 5-6 months of feeding, large-sized mandarin fish of the year are released, and they can grow to 0.4-0.5 kg at the end of the year, with a survival rate of 80%, and 1 kg of commercial mandarin fish can be produced per square meter. One-year-old mandarin fish weighing 50-100 grams are released, and each fish can reach 0.5-0.7 kg at the end of the year, with a survival rate of about 90%, and 1.5 kg of commercial mandarin fish can be produced per square meter.