Columnaris (Mouth Fungus)
Frequently mistaken for a fungal infection (Cotton Fin) due to its mold-like lesions, this is a common bacterial infection in aquarium fish.
It’s highly contagious and the outcome is often fatal.
- Frayed and ragged fins
- Ulcerations on the skin
- Epidermal loss
- White or cloudy, fungus-like patches. Particularly on the gill filaments
- Mucus on the gills, head, and dorsal regions
- Gills will change color. Becoming light or dark brown
- Breathing rapidly and laboriously
- Loss of appetite
Columnaris is common where high bioloads or stressful conditions exist. These can be due to overcrowding, injury, inadequate diet, poor water quality, and unstable pH.
The bacteria can stay active in your tank for up to 32 days if the hardness is 50 ppm or more.
The disease does not survive in salt solutions of 1% or higher. So salt can be a great initial treatment if the case is less severe.
The use of a separate treatment bath can be great for infected fish, but, in severe cases, treatment of your entire tank is a must.
Another option would be to buy an antibiotic that treats gram-negative bacterial infections. Oxytetracycline is regarded as a very effective option.
To prevent the spread, remove any dead fish ASAP. This will stop surviving fish from picking at the infected fish, which can result in internal infection.Author – modestfish