Ornamental Fish Production and Management

10.1.4 Fungal diseases

Fungus (Saprolegnia)

Symptoms: Tufts of dirty, cotton-like growth on the skin, can cover large areas of the fish, fish eggs turn white.

Fungal attacks may lead to other health problems like parasitic attack, injury, or bacterial infection. The symptoms are a gray or whitish growth in and on the skin and/or fins of the fish. Eventually, if left untreated, these growths will become cottony looking. The fungus, if left untreated, will eventually eat away on the fish until it finally dies.

Treatment: Use a solution of phenoxethol at 1% in distilled water. 10 ml of this solution to be added per liter of aquarium water. The treatment should be repeated after a few days if needed. If the symptoms are severe the fish can be removed from the aquarium and swabbed with a cloth that has been treated with small amounts of povidone iodine or mercurochrome. For attacks on fish eggs, most breeders will use a solution of methylene blue adding 3 to 5 mg/l as a preventative measure after the eggs are laid.