Control methods of clonorchiasis in fish

Main pathogens: diplostomum, cercariae, metacercariae.

Harm species: silver carp, bighead carp, etc.

Control period: May ~ August.

Identification characteristics: The body of the sick fish is black and thin. In the early stage of acute infection, the sick fish makes jumping struggle on the water surface, or swims rapidly in the water. When the physical strength is exhausted, it swims slowly, head down and tail up, loses balance, the fish body bends or the head and orbit are severely congested; in chronic infection, the cornea of the fish eye is cloudy and milky white, and in severe cases, the lens falls off and becomes blind.

Control methods: (1) The best plan is to kill the first intermediate host and the final host, cut off the life cycle of the trematode, and achieve the goal of radical control. (2) Sprinkle 0.5 g of copper sulfate into the whole pool for each cubic meter of water, and repeat once after 1 day. (3) Dibutyltin oxide 0.25 g/kg fish weight mixed with feed for 5 days. (4) 0.2~0.3 g of thiobischlorophenol per kilogram of fish weight was mixed and fed for 3~5 days. (5) Tie water grass (best bitter grass) or dry grass into several bundles, stack them in the water around the pond in the evening to trap the trematode, fish them up the next morning, and put them in the sun to kill them.