Fungal diseases of fish

Saprolegniasis (Water mold disease)

• The causative agent is Saprolegnia parasitic
• Develops in injured, weakened, diseased, or dead fish.
• External lesions open the way for the disease pathogen.

Disease symptoms

• Characterized by wooly, whitish, or lightly brown blotches on the skin, fins, eyes, mouth, gill, or unfertilized eggs the first indication is the dullness of body color.
• Ulceration of the skin, exposure of jaw bones, blindness, inflammation of the liver and intestine
• Infected fish rub their body against hard surfaces due to irritation.
• Fish show abnormal movement.

Control measures

• Treat primary injuries of fish.
• Use a 1:10 solution of iodine or 1% potassium dichromate for cleaning the affected part.
• Dip diseased fish in 0.3% common salt solution or 1:2000 solution of CuSO₄ or in 1:1000 KMnO₄ solution for 5-10 minutes.
• Treat fertilized eggs with 3-4% formalin or 1-5% salt for 10 minutes.
• Treat infected eggs in an ianncubation tank with malachite green @ 5g/L.