Techniques of single culture of mandarin fish in ponds

Mandarin fish is also known as mandarin fish. Compared with ordinary "domestic fish," Mandarin fish has a low yield per unit area, but its output value is high. In recent years, by the majority of farmers of all ages, become famous excellent fish hot spots. The technical points of pond single culture mandarin fish are as follows.

1. Pond conditions. Choose the leeward sunny, sufficient water, fresh water without pollution, convenient irrigation and drainage places to build mandarin fish pond, loam bottom, less silt or newly excavated pond is ideal. The area is 600-3000 square meters, and the water depth is about 2.0 meters. Aerator and bait fish cultivation pond are equipped, and some submerged aquatic plants, such as duck tongue grass and verticillata, are planted around the pond to serve as a hidden place for mandarin fish and absorb excessive fertilizer in the pond.

2. stocking specifications. The fish size is 5-6 cm. Because mandarin fish have the habit of eating each other, it is required to stock the fish species in order.

3. stocking density. The stocking density is closely related to pond environment, feed fish supply and culture technology, generally 800-1200 fish/mu is appropriate.

4. Feeding fish. The area ratio of mandarin fish pond to bait fish pond is about 1:4. Feed fish should adopt the breeding method of multi-pond, different density feeding, multi-catch and step-by-step thinning to ensure the synchronous growth of feed fish and mandarin fish. Generally, crucian carp, carp and bighead carp, which are easy to catch and like to eat, are selected as bait fish. Meanwhile, carp and crucian carp that have not been eaten can absorb residual bait or rotten matter at the bottom of the pool to prevent water quality from deteriorating and facilitate the cultivation of mandarin fish. In order to ensure that the feed fish specifications are appropriate, the feeding and growth of mandarin fish should be checked frequently. The growth and specification of bait fish are controlled by adjusting the density and feeding amount. The breeding density is 6-8 times that of conventional fish, usually about 1 million fish/mu, and artificial feed can be added.

V. Baiting. 15-20 days before stocking mandarin fish, pre-bait fish are cultivated in the pond so as to have palatable bait when fingerling is placed in the pond. After stocking, bait fish should be put into the pond in time. The palatable length of bait swallowed by mandarin fish is 1/4-1/3 of its own length, and its body height should be less than the caliber of mandarin fish. Mandarin fish usually preys on active prey by sneak attack at night, and the maximum amount is swallowed at about 8 o'clock in the evening. Feed once a day, feeding amount to meet the mandarin fish 4-5 days food intake is appropriate, otherwise the fish body is easy to cause a large number of deaths. 7-9 Month is the peak season for mandarin fish growth, so it is necessary to increase the feeding amount in due time; in winter, the feeding intensity and growth rate of mandarin fish slow down, so the feeding amount can be reduced appropriately. It is best to regularly detect the growth rate of mandarin fish month by month. If it is found that the bait is insufficient or not palatable, it should be adjusted in time. The ratio of mandarin fish to bait fish is 1:5-10. In order to ensure the normal growth of uneaten bait fish, appropriate rapeseed cake should be fed at the same time.

VI. Water quality management. Mandarin fish has poor tolerance to hypoxia and high requirements for dissolved oxygen in water. According to the determination, under the same conditions, the asphyxiation point of mandarin fish fry is 3.1 times that of silver carp, 5.1 times that of carp and 12.5 times that of crucian carp. Once the water is oxygen-deficient and the fish floats, mandarin fish will die first. Therefore, the cultivation water of mandarin fish should be fresh, pollution-free, high dissolved oxygen, rivers, lakes and reservoirs with less pathogenic organisms. If it is other water sources, it should be precipitated and filtered to avoid harm to the pond by harmful organisms. In the breeding process, good water quality can be ensured by controlling stocking density, flushing, turning on oxygenator and regularly sprinkling quicklime. It's best to keep the pool water flowing. If the dissolved oxygen is above 6 mg/L, the transparency is 30-40 cm, the pH is neutral or slightly alkaline, etc., it can play a positive role in the growth and disease prevention of mandarin fish.

VII. Prevention and treatment of diseases. Disease control of mandarin fish, like other aquatic products, must implement the policy of "prevention first, prevention more important than cure, early cure if there is disease, prevention first if there is no disease." Requirements: (1) Strictly clear the pond according to conventional methods before stocking fish species, and the stocked fish species (including bait fish) shall be healthy and disease-free, and shall be soaked in 2% salt water for 10 minutes before entering the pond;(2) Try to avoid fish body injury when moving fish species;(3) Check immediately when inspecting the pond and finding abnormal feeding and action of mandarin fish, and take corresponding measures;(4) Take measures such as regularly sprinkling 30mg/L quicklime or feeding bait during the epidemic season of fish disease (May to October) to prevent fish disease. For bacterial and parasitic diseases, 0.7 mg/L copper sulfate and ferrous sulfate (5:2), 0.2-0.4 mg/L B type mirex, 1 mg/L bleaching powder or 10 mg/L formalin can be used respectively.