How to prevent and treat ichthyophthiriasis in freshwater pomfret during overwintering?

Ichthyophthiriasis is the second most common disease of freshwater pomfret during overwintering. Its incidence rate is lower than that of saprolegniasis, but the mortality rate per unit area is higher than that of saprolegniasis, and it can also lead to concurrent saprolegniasis.

1. Pathogen

Ichthyophthirius multifiliis.

2. Symptoms

Many dot-like cysts are visible to the naked eye on the body surface and gill filaments, covered with a layer of white mucus; microscopic examination of these white-spot mucus can reveal the presence of Ichthyophthirius multifiliis. The tissue at the parasitic site becomes inflamed and necrotic, and the gills sometimes bleed and appear dark red. When the cornea is parasitized, it sometimes causes cloudy eyes; diseased fish have reduced appetite, become emaciated, swim at the water surface, and have difficulty breathing, which can cause mass mortality of fish.

3. Prevention and treatment methods

(1) Soak the fish in 150 ml of formalin solution per cubic meter of water for 15-20 minutes, once every other day, with 2-3 treatments per course.

(2) Splash formalin throughout the pond at 15-30 ml per cubic meter of water to make the pond water a concentration of 20 mg/L, use once every other day, for 2-3 consecutive times.

(3) For each mu of water surface, use 0.5 kg of ginger mashed, 0.25 kg of chili powder, add 10 kg of water, boil in a pot into spicy ginger soup, then add 15 kg of cold water to dilute, and splash throughout the pond. Once a day, for three consecutive days.