Key techniques of mandarin fish culture in pond

1. Mandarin fish living habits: bottom fishes live in still water and rivers, lakes and reservoirs with certain flowing water, especially in shallow lakes with abundant water plants. It generally lurks at the bottom of the water during the day, looks for food everywhere at night, has the habit of burrowing, and does not like to live in groups. The suitable water temperature for life is 1532 ℃, and it is inactive and ingested when the water temperature is below 7 ℃. In pond culture, mandarin fish often lie at the bottom of the water and hide in shallow holes.

2. Food habits of mandarin fish: ferocious carnivorous fish, eating on the fry of other fish after hatching, like to eat live bait, cannibalize each other when hungry, the fry stage can swallow fry equivalent to 70% of its own length of other farmed fish, the specification of the feed fish can only be swallowed according to its caliber, regardless of the length of the fish body. Under the condition of artificial culture, when the kinds of bait are various and abundant, fish with slender body, soft fins and small individuals are often selected as food. The length of the largest food fish easily swallowed by mandarin mandarin is 60% of its own length, but the palatability is better when it is 26-36%.

3. The growth rate of mandarin fish: under the condition of artificial culture, the bait is palatable, sufficient and grows fast. The average body length of 1 winter-old mandarin fish raised in cage is 31.68 cm, which is equivalent to that of 3-winter-old mandarin fish in natural water. The growth of mandarin fish before 2 years old is faster than that of old fish, and that of 1 year old fish is faster than that of 2 years old fish. Mandarin fish did not stop feeding completely in winter and continued to grow, but the feeding intensity and growth rate slowed down.

4. The pond area of mandarin fish culture is 4 mu, the minimum is not less than 1 mu, the maximum is not more than 10 mu, the pond area is too small, the water quality changes quickly, and it is difficult to control; the pond area is too large, and the bait fish is relatively scattered, which is not conducive to the feeding of mandarin fish. The pond leeward to the sun, east-west direction, length-width ratio 3:2, the bottom is flat, sandy loam, little or no silt of the newly excavated pond, water depth of about 1.8 to 2.5 meters, adequate water source, fresh water quality, convenient access and drainage, river and lake reservoir water is the best, preferably micro-flow water. Before entering the pond, the mandarin fish fry should be thoroughly cleaned and disinfected and an aerator should be installed.

5. The production of bait fish in this pond: 15 days before the mandarin fish was released, the fish pond whose toxicity disappeared after disinfection was put into 60 ~ 800000 bait fish / mu per mu, and the bait fish in the pond was cultivated to 1.2~2.0cm/ tail.

6, mandarin fry under the pond time: when the bait fish in the pond is cultivated to the 1.2~2.0cm/ tail, it just provides sufficient and palatable pre-feed fish for mandarin fish after release, and appropriate amount of water peanuts and water hyacinth are put around the pond for mandarin fish to perch. After that, the body length of the bait fish was controlled to be the body length of mandarin fish.

7. Stocking density and specification of mandarin fish: 1000,1200 fry of mandarin fish with 3~5cm/ tail per mu.

8. matching production of bait fish: the bait fish in the main culture pond of mandarin fish can be fed by mandarin fish within one month under normal circumstances. Through one month of feeding, the body length of mandarin fish can generally reach 11cm. In accordance with the requirement of mandarin fish feed coefficient 1 / 4 / 5 in the equipped bait fish pond (3 / 4 times that of mandarin fish culture pond), taking advantage of multiple ponds, the feeding methods of different densities, multiple fishing and gradual thinning are adopted to raise bait fish, and the body length of bait fish is about 50% of that of mandarin fish in the same period, so as to ensure the synchronous growth of bait fish and mandarin fish so that mandarin fish can eat.

9. The optimum water temperature for mandarin fish growth: the growth water temperature of mandarin fish is 18-30 ℃, and the optimum water temperature is 23-28 ℃. In this range, the food intake increases and the growth rate increases with the increase of water temperature.

10. feeding of bait fish: during the period of culture, the method of feeding bait fish at intervals can be adopted according to the change of water temperature, once in the early and late 7-10 days, and once every 5-7 days in the middle stage (high temperature in July, August and September). Feed fish need appropriate amount, the density is too thin, mandarin fish to chase bait fish will consume too much physical energy, which is disadvantageous to growth; too dense, will increase the total oxygen consumption, will cause anoxic floating head of mandarin fish, which is not conducive to the growth of mandarin fish.

11. Feeding amount of bait fish: each feeding amount is 810% of the total amount of mandarin fish, and the ratio of mandarin fish to bait fish is 1Ru 5mm 10. After the bait fish is put into the mandarin fish pond, there is still a period of growth time, and a small amount of concentrate can be fed as appropriate.

12. Water quality management: mandarin fish like fresh water quality, but their tolerance to hypoxia is poor, so it is very important to strengthen water quality management. Before the mandarin fry is released, half of the pond water should be drained, then poured into the pond to make the water clear, and then put in the mandarin fish fry. Mandarin fish are very sensitive to acidic water quality. From June to October, 20 jin of raw calcareous water per mu was sprinkled in the whole pond every 15 to 20 days, keeping the pH value 7 to 8, which was beneficial to the feeding and growth of mandarin fish.

13. Water injection and water change by stages: at the initial stage of stocking, fresh water is injected once every 7 to 10 days, and each time the amount of water injected is 10: 20% of the water volume of the pool. In the first and middle of July, the pool water is gradually deepened to more than 1.5 meters. From mid-July to September, the water is changed as much as possible every two weeks with the increase of water temperature. Master the transparency of the water body in 30~40cm, and when the water is less than 30cm, the pool water should be changed. It is better to keep the circulating water regularly, so that the dissolved oxygen in the water is always more than 4 mg / L.