Saltwater Tank Fish Diseases

Saltwater aquarium fish diseases are caused by parasitic, bacterial, viral and fungal infections. If you have a fish showing signs of sickness, it should be quarantined immediately in a separate tank. Poor water quality, overcrowding and changes in temperature can also cause stress in fish, leading to illness.

  1. Marine Ich

    • Marine Ich is a common parasitic infection that spreads quickly among fish in captivity. It appears as tiny white spots on the fins and body. It may cause the fish to swim erratically, rubbing itself on ornaments. If untreated, the fish will likely die within two months.

    Marine Velvet

    • Marine Velvet is another common parasitic infection. It appears as light brown or grey areas of discoloration on the body. The fish may rub itself against tank ornaments and exhibit rapid gill movement. If untreated, this infection spreads to the respiratory system and is fatal.

    Uronema

    • Uronema is a parasitic infection that appears as a bloody sore. Cloudy eyes and sluggish movement are also symptoms. If the infection spreads to the gills, the fish will die immediately.

    Black Spot

    • Black spot is a flatworm that infects and deteriorates the body and fins of a fish. It appears as a series of black spots and may cause the fish to rub against aquarium ornaments. This disease is fatal if not treated.

    Fin Rot

    • Fin rot is a bacterial infection that eats away at the fins of a fish, causing them to split and appear tattered. If left untreated, this disease spreads to the gills and is fatal.

    Wasting Disease

    • Wasting disease is a bacterial infection that attacks the internal organs of a fish. There are few external symptoms in the early stages, but in the latter stages the fish may become emaciated and lethargic, exhibit rapid gill movement and show signs of physical degeneration. This disease is difficult to catch in time to effectively medicate. It is generally fatal.

    Cauliflower Disease

    • Cauliflower disease is the most common viral infection in saltwater aquarium fish. It appears as white, cauliflower-like lesions on the fins and body. This disease is not fatal. The fish should be quarantined and left to overcome it naturally.

    Whirling Disease

    • Whirling disease is a fungal infection that attacks the internal organs of a fish, causing death within a few months. The fish becomes emaciated and discolored, its scales protrude and it exhibits fin damage, external ulcers and a curved spine. You may notice that the fish begins to swim erratically. Early treatment can be effective.