What are the prevention and control methods for fish diplostomiasis?
Prevention and control methods for fish diplostomiasis
Main pathogens: Diplostomum spp., cercariae, metacercariae.
Affected species: silver carp, bighead carp, etc.
Optimal control period: May to August.
Identifying features: Diseased fish have a darkened body and are thin and weak. In the early stage of acute infection, diseased fish leap and struggle at the water surface, or swim rapidly in the water; when their energy is exhausted, they swim slowly, head down and tail up, losing balance, with the body bent or severe congestion around the head and eye sockets. In chronic infection, the cornea of the fish eye becomes cloudy and milky white; in severe cases, the lens falls out and the fish becomes blind.
Prevention and control methods: (1) The best option is to eliminate the first intermediate host, the pond snail (Lymnaea), and the final host, the gull, cutting off the life cycle of Diplostomum spp. to achieve a radical cure. (2) Apply 0.5 g of copper sulfate per cubic meter of water, dissolved in water and splashed over the whole pond; repeat once after 1 day. (3) Feed 0.25 g of dibutyltin oxide per kilogram of fish body weight mixed into feed, for 5 consecutive days. (4) Feed 0.2-0.3 g of bithionol per kilogram of fish body weight mixed into feed, for 3-5 consecutive days. (5) Tie aquatic plants (Vallisneria is best) or terrestrial grass into several bundles, place them in the water around the pond in the evening to trap Diplostomum spp., then retrieve them early the next morning and dry them in the sun to kill the parasites.
Affected species: silver carp, bighead carp, etc.
Optimal control period: May to August.
Identifying features: Diseased fish have a darkened body and are thin and weak. In the early stage of acute infection, diseased fish leap and struggle at the water surface, or swim rapidly in the water; when their energy is exhausted, they swim slowly, head down and tail up, losing balance, with the body bent or severe congestion around the head and eye sockets. In chronic infection, the cornea of the fish eye becomes cloudy and milky white; in severe cases, the lens falls out and the fish becomes blind.
Prevention and control methods: (1) The best option is to eliminate the first intermediate host, the pond snail (Lymnaea), and the final host, the gull, cutting off the life cycle of Diplostomum spp. to achieve a radical cure. (2) Apply 0.5 g of copper sulfate per cubic meter of water, dissolved in water and splashed over the whole pond; repeat once after 1 day. (3) Feed 0.25 g of dibutyltin oxide per kilogram of fish body weight mixed into feed, for 5 consecutive days. (4) Feed 0.2-0.3 g of bithionol per kilogram of fish body weight mixed into feed, for 3-5 consecutive days. (5) Tie aquatic plants (Vallisneria is best) or terrestrial grass into several bundles, place them in the water around the pond in the evening to trap Diplostomum spp., then retrieve them early the next morning and dry them in the sun to kill the parasites.