Control of concave and convex disease of farmed eel

Pathogen: eel worm is the pathogen of eel concave and convex disease, belonging to the order microsporidia. The spores are small and the structure is simple. The eel worm parasites in the lateral muscles of the body, and the spores are scattered inside and outside the muscle tissue, at the same time, the surrounding tissue is dissolved, the body surface is sunken, showing uneven, so it is called concave-convex disease. There is no special restriction on the epidemic period of the disease. It can be infected in the water of 15 ℃ ~ 30 ℃. The higher the temperature is, the faster the spore development is, but the course of the disease is very slow below 25 ℃. Both young and adult eels can be infected. White eels get sick in heated eel ponds. The disease is particularly harmful to young eels, even if it does not die, it can not be bred into adult eels of commercial value, and it is easy to spread. Spores in water or mixed into feed can cause infection.

The sick eel has no loss of appetite at the initial stage, and it still has a certain ability to ask for food with the development of the disease, and it takes quite a long time to find special external lesions. Although it still grows slowly, it has lost its commercial value, and once it is infected with other germs, it will invade and weaken the muscles of the whole body and die. Japanese eel, European eel and American eel can all be infected with the disease.

Prevention and control: carefully observe the fish in the process of acquisition to avoid buying sick eels. Avoid excessive density when raising and keep the water quality good. Diseased eels found in capture and sorting should be picked out and destroyed immediately to prevent infection. It is appropriate to turn the soil to dry before stocking, and thoroughly clear the pond with a large dose of quicklime.