Cast fish seeds in autumn and beware of "fish colds"

Autumn is the golden season for the massive application of silver carp, grass, green, bighead carp and other fish species to the reservoir. However, many households have found that within two or seven days after the release of fish fry, diseased and dead fish are often found on the surface of the store. these diseased fish lose luster and increase mucus on their body surface. in severe cases, they cause paralysis, stiffness and death.

The above symptoms are typical "colds", mainly due to sharp changes in water temperature, fish skin nerve endings have been strongly stimulated and internal organ activity disorders, the mortality rate is as high as 20% to 60%. The fish species are shipped from the fish pond to the edge of the reservoir and released directly to the reservoir. Due to the large difference in water temperature between the two places, even if the activity of the fish species is observed with the naked eye during stocking, they will still catch a cold and die after entering the reservoir. So, how to control it?

First, the temperature difference should be adjusted. 6 the cage should be placed in advance at the bay of the reservoir. When the difference between the water temperature of the fish fry pond and the water temperature of the reservoir is more than 3 ℃, the temperature difference should be adjusted gradually and wait for the fish species to adapt before entering the reservoir. The method is to gradually add reservoir water to the tank carrying fish fingers. when the water temperature of the tank to be loaded is close to the water temperature of the reservoir, keep it for 10 to 30 minutes, slowly pour the fish and water into the cage, so as to adjust the water temperature. let the fish species adapt to the new water quality environment, and the fish species can swim freely into the reservoir after 2 hours in the cage.

The second is drug prevention. According to the characteristics that the water temperature of the reservoir is often lower than that of the fish fry pond, garlic combined with urea can be used to prevent the "cold" of fish fingers. the effect is very good, and there are no side effects on fish species. In every 500 kg of water carrying fish fry, add 1.3 kg garlic paste, put the fish fry into the water tank, then wrap 2.5 kg urea in cotton cloth and let it sink into the bottom of the fish tank. When urea slowly dissolves, it absorbs the heat in the water and lowers the water temperature of the temporary fish culture. When the water temperature is close to the reservoir water temperature, it is put in.