High Temperature Affects Prawn Foraging and Molting in Summer

In the high temperature season in midsummer, hot weather, strong light, high water temperature and poor water quality affect the foraging and molting of prawns. Key points of shrimp culture in South America in midsummer:

Shrimp culture

First, use water to control temperature and regulate oxygen.

With the increase of water temperature and the growth of prawns, the water depth increases continuously, especially in the middle and later stages of shrimp culture, the water level must be increased to 1.8-2 meters, and the high temperature period should be kept above 2.2 meters. To this end, in the spring tide, it is necessary to drain once a day; in low tide and low water periods, mechanical drainage and irrigation is required, and the daily water exchange is about 50%. In the high temperature period, full discharge and full irrigation can effectively control the water temperature within 30 ℃, the transparency of pond water is 35cm, the dissolved oxygen content is about 5 mg / L, and shrimp can grow quickly, high quality and high yield. However, when changing water, it is best to install a 60-mesh mesh to filter water at the inlet in order to prevent the introduction of tiny living organisms carrying shrimp fulminant epidemic virus.

Second, scientific bait in stages.

When prawns grow above 4cm, they are mainly fed with low-value shellfish bait such as Corbicula, 6-8 kg per 10, 000 shrimp per day, 50 kg per 10, 000 shrimp per day for body length 8cm, and 100 kg per 10 000 shrimp per day for body length 12cm. In case there is not enough bait for shellfish, it can be fed with formula feed. When the body length is 4cm, it is fed 1.5kg per ten thousand prawns per day, and when the lower body length is increased by 0.5cm, the dosage is increased by 0.3kg to 0.5kg, and when the body length is 10cm, the dosage is increased by 0.7kg to 0.8kg. For example, with chilled fish, 1 kg formula feed is discounted with 2.5 kg chilled fish. Prawns lie dormant during the day and go out at night, with frequent nocturnal activities and a strong appetite; latent during the day, the appetite is weakened. So feed before sunrise and after sunset, throw 1UBG 3 in the morning and 2UX 3 in the evening. The bait is placed on the platform around the shrimp pond so that all prawns can be eaten. When casting bait, stick to "four less and four more", that is, less in the early stage and more in the later stage; less in the morning and more in the evening; less in the low tide and more in the spring tide; less in the molting of prawns and more in the normal growth. "two do not cast", that is, do not cast bait, ring ditch and deep water.

Third, beware of shrimp disease harm.

In the high temperature season in midsummer, shrimp has poor appetite and activity, and the metabolic level decreases, coupled with the deterioration of pond water and the breeding of pathogenic organisms, which is easy to cause shrimp disease. For this reason, first of all, the feeding amount of shrimp should not be too much and too concentrated, so as not to deteriorate the bait and pollute the water quality. In particular, fresh bait is easy to deteriorate in high temperature weather, and prawns are easy to be poisoned to death. In order to reduce water pollution, water should be changed frequently. Secondly, we should pay attention to dredging. In the high temperature season in midsummer, the density of prawns should be adjusted reasonably to make prawns have some active water bodies.

Fourth, prevent the floating head of prawn.

At midnight and before dawn, there is less oxygen in the pond, which is the time when floating heads of prawns are most likely to occur. If the floating heads of prawns and white prawns are found, small miscellaneous fish gather to the edge of the pool, start the aerator in time or change water constantly to increase the amount of dissolved oxygen in the pond. Usually, it is also necessary to remove silt debris from shrimp ponds to ensure fresh and good water quality to prevent shrimp floating head.