It's good to put the fish in the box in autumn.

After fattening in the pond in autumn, the fish species are generally strong and easy to adapt to the cage environment. At the same time, when the caisson overwintered with large water surface, not only the body weight consumption of the fish species overwintering was less than that in the pond, but also the fish began to eat earlier after overwintering in spring, and the growth period was about one month longer than that of the fish in the box in spring. The growth rate of fish is faster and the yield is significantly increased. Compared with the species in the box in spring, the caisson overwintering species grow about 30% faster and the size out of the box is about 35% larger. Therefore, the overwintering of fish in the box in autumn is a more scientific release mode. Its operating technical requirements are as follows:

1. Time to get into the box. Generally, it can be carried out from late September to mid-October, and it is suitable when the water temperature is 15 ℃ ~ 18 ℃, but not when the water temperature is below 10 ℃.

two。 Disinfect the fish. Disinfection before entering the box can be combined with fish transportation, that is, 20 to 30 minutes before the transportation arrives at the destination, the medicine is melted and put into the transport canvas basket or fish bucket. Generally, methylene blue or erythromycin for aquatic products can be chosen, and the drug usage should be accurately calculated and can not be estimated at will.

3. Prepare the cage. The complete and undamaged double-layer cage was put into the water 7 to 10 days before the fish was put into the box, so that a layer of algae or sedimentary material could be attached to the surface of the cage, and then the fish seed was put in to reduce the scratch of the new cage on the fish.

4. In-box management. The fish species should be given bait for a period of time after entering the box, so that the injured parts of the fish species can be recovered in time in the process of fishing and transportation, so as to reduce the probability of fish disease caused by infection.

5. Management in front of caissons. The caisson must be fed with bait until the fish are not eaten before overwintering. The water temperature is about 5 ℃ ~ 6 ℃ in order to keep the fish physically strong before overwintering and not to cause the fish physique to be weak because of stopping eating prematurely.

6. Master the water temperature of the caisson. The water temperature in the caisson should be about 4 ℃, when the water temperature in the upper and lower layers is basically the same, the convection between the upper and lower layers ends, and the physiological state of fish sinking is stable and will not be disturbed by the change of the water layer.