Fungus on Fish:

Fish in aquariums are often prone to fungal infections. The fungus, when present on the fish resembles or appears like fine white colored threads, passing through organic material and these may start growing on the fish, appearing like pieces of cotton wool. There are several types of fungi that might occur on fish. Fungus hyphae is the cotton like fungus which may grow anywhere on the body. There is also mouth fungus which is a grey colored filament that grows only around the mouth.

There are several types of fungi on fish. Some common fungal species in aquariums are achyla and saprolegia. These are present in almost all aquariums. They feed on organic material like the fish food that remains uneaten or the feces of the fish. Though fungal spores are present in aquariums, they usually do not harm the fish. They do invade living tissue and other organic material but are not able to harm the fish because of the thick upper membranes on the fish which prevent the fungi from affecting them.

Fungus will develop on the fish only if the thick tissue and the layer of mucus on the fish’s skin are broken or damaged. In such a case, fungus develops rather quickly. If you do not clean your aquarium regularly or handle your fish rather roughly, they may develop fungus. Fish may also often fight with each other and damage the fins or skin of each other. These open wounds are then not only an invitation to fungus, but could also foster other skin conditions like ulcers, itch, and others.

Characteristically, fish have an extremely weak immune response when they are not taken care of properly. If the water is cold or unclean, fish may develop a variety of diseases. It is therefore recommended that the quality of water should be good. It is also important to keep freshwater fish in water which has the right chemistry. If this is not done, the fish may develop fungal infections.

Fungus should ideally be treated immediately because once it starts to grow, it spreads rather quickly. Such a fungal attack makes the fish more susceptible to other secondary infections. If fungus is not remedied promptly, it may grow to a significant amount and then harm the fish. You can add a few drops of tea tree oil or a dash of salt to the fish tank to treat fungal infection on fish. Organic dyes with malachite green are also often used as treatment, but whatever you use it would be best to first consult your local aquarium, as salinity levels and even the dosage levels may vary greatly for different species.