Mouth Fungus Disease in Marine Fish

The first symptoms of mouth fungus is a grey or white line around the lips of the fish. This line gives way to gray and white patches that form around the mouth. If left untreated, mouth fungus will appear as tufts of grey and white material that stick out of the mouth. It is important to treat mouth fungus as soon as it is detected since the disease can be fatal to fish.
    • Beta Fish

    Bacteria

    • Mouth fungus is not actually caused by a fungus. The condition is actually caused by the columnaris bacteria.

    Toxicity

    • The bacteria that causes mouth fungus is toxic to fish and can lead to problems with the fins, gills and internal organs in addition to the mouth.

    Starving

    • If not treated right away, mouth fungus will become severe enough to prevent the fish from eating.

    Treatment

    • Mouth fungus can usually be effectively treated with penicillin.

    Always Present

    • It is impossible to completely eliminate the columnaris bacteria from an aquarium or waterway; however, poor water quality and environmental changes can increase the likelihood of a fish contracting mouth fungus.