Fungal infection in aquarium fishes

Fungal infections are  the most common diseases seen in tropical fish. Because fungal spores are found in all fish tanks, they can quickly colonize and create problems in stressed, injured, or diseased fish. Initially, you’ll notice a gray or whitish growth in and on the skin and/or fins. Eventually, as fungus continues to eat away at the fish’s body, the fish will die. Most fungal infections have a characteristic white fluffy appearance and are commonly known as ‘cotton wool disease.’ 

Fungi are present throughout most aquariums, but certain conditions increase the possibility of fungal infections like poor water quality, poor hygiene, dead fish or large amounts of decomposing organic material in the tank and fish that are injured, old, or have other diseases. Keeping brackish water ( salt water and fresh water mixed together. It is saltier than fresh water, but not as salty as seawater) fish in freshwater conditions can also lead to fungal infections

Treatment for cotton wool disease includes salt baths or the antifungal agent. In some instances, the entire tank is treated, but if individual infections are present, treating the fish in a separate hospital tank is preferable. Individual topical application of the antifungal and antibacterial agent Gentian Violet is also a treatment option.

 If you see a fungal infection in your fish, make sure to check the water quality and insure that your tank is providing a healthy, safe, natural environment for all of your fish. Tanks with fish that have reoccurring fungal infections need to be examined for tank hygiene, filtration and water quality. Healthy tanks should rarely have fish with fungal infections. Fungus is easily prevented. Avoiding injuries to your fish is essential, and this means minimizing handling and taking care not to mix specimens that might damage one another.