(Flexibacter columnaris, Cytophaga columnaris, Bacillus columnaris)
Columnaris is flexibacter and used to be called chondrococcus or cytophaga before being changed to flexibacter by Leadbetter in 1975.
Columnaris (Flexibacter columnaris) or Cotton Wool Disease is a bacterial infection.
Columnaris flexibacter and Cytohaga columnaris bacteria can cause greyish white growths, similar to fungus on the head area of fish, the gills and the fins. These fist appear as whitish marks before the tufts appear, accompanied by red sores. Eventually the internal organs can be infected.
Columnaris is better known as fin rot or fungus.Columnaris is also known as bacterial cold water disease and bacterial gill disease. These are myxobacters (bacteria that form colonies in self-produced slime; inhabit moist soils or decaying plant matter or animal waste) in their common forms. Its name is derived from columnar shaped bacteria, which are present in virtually all pond environments. When looking down a microscope, run to the end of the cover glass and you will see what looks like very small tubular worms - Columnaris does not like the light.
Do not confuse it with the spores of saprolegnia (Saprolegnia is a genus of freshwater mould often called a "cotton mould" because of the characteristic white or grey fibrous patches it forms) the cotton wool ball seen on damaged fish.
Columnaris needs to be confirmed by using a microscope as to the naked eye it looks like saprolegnia and is often treated as fungus with no result.
Symptoms
white tufts around mouth initially
spread of tufts to body and fins
ulcers
thin appearance
Transmission
Transmission of Columnaris is through wounds and it favours the mouth and head regions attacking the fins when the bacteria has invaded the fish body wall. The bacteria is present in all bodies of water no matter how clean and well run the system and is a fan of cool conditions spring and autumn.
As in most disease and parasite problems the bacteria are most likely to infect fish that have been stressed by such conditions as inferior water quality, inadequate diet, inexpert handling and shipping.
Columnaris can enter the fish through the gills, mouth, or via small wounds on the skin. The disease is highly contagious and may be spread through contaminated nets, specimen containers, and even food. Therefore it is important that all equipment is kept scrupulously clean and seperate nets etc used on quarantine tanks.
Treatment
Treatment with anti bacterial medicine such as Acriflavine is usually effective. Acriflavine is safe to use with Sturgeon.
However, Columnaris requires treatment at the onset or it cannot be controlled with ANY method including heat and antibiotics.
