Description

The symptoms correspond to those of gill worm infestation #51#. Similar to Dactylogyrus infestation, though, no worms are found when the gills are examined. Branchiomyces is a fungus for which there is presently no efficient medical treatment. Gill rot is highly infectious, but, fortunately, very rare and tends to be found in very silty water bodies used for fish farming.

The fungus settles in the blood vessels of the fish’s gills. Thus, the blood circulation is affected and the gills have a blotted aspect with brownish areas (due to hemorrhage) and whitish area (where the blood flow has been interrupted and the necrosis appeared). The regions with necrosis are often invaded by the protozoan Saprolegnia, which thus becomes a secondary infection.

The sick fish becomes first lethargic, its skin colour becomes bluish due to hypoxia, and if no treatment is applied, the infection spreads to other places of the fish’s skin, although usually the fish will die because of the hypoxia before the symptoms spread out.

The fish seem to suffocate and desperately try to swallow the air from the water surface. The gills look faded, having alternating areas with necrosis and with healthy tissues. If the disease is not treated as soon as possible, the fish will die because the affected gills cannot ensure the correct oxygenation of the fish’s body.

The fungi which cause branchiomyces reproduce in the infected tissues and the desquamation of the tissues with necrosis releases the spores of the fungi in the aquarium where can rapidly infect other fish.

The disease is often found in Eastern Europe and usually occurs in ponds, but also in the aquariums where there are improper living conditions.

Branchiomyces is caused by the fungus Branchiomyces sanguinis and the fungus Branchiomyces demigrans, which usually develop in the rotten organic matter from ponds and lakes. In the aquarium, the fungus develops if certain environment conditions are unfavourable: the level of the pH is between 5.5 and 6.5, there is low oxygen concentration, there are a lot of algae, there is a high level of nitrites and nitrates, there isn’t a proper water filtration and the aquarium isn’t cleaned in time. The fungus develops and temperatures raging between 14 and 35 °C, but it best proliferates between 21 and 29°C, exactly the necessary temperature in any aquarium.

Examined under the microscope, the fungus resembles a snowflake, unlike the majority of fungi which are made of long filaments.

The disease has a high rate of mortality, and certain aquarists recommend quarantine, while others the complete disinfection of the aquarium in order to stop the spread of the fungi.

Treatment

The infected fish can be saved if the disease is diagnosed in time. The sick fish must first be put into a quarantine aquarium. The main treatment solution is to then give the fish a 10 minutes bath in a water with 3% salinity. When it’s put back in the fresh water, it’s necessary to scrape off the infected tissues, followed by a disinfection with a cotton swab soaked in methyl blue. If the fungus cannot be easily eliminated, you should give the fish another bath in the saline solution.

Sometimes, the skin of the infected fish can break, but usually these wounds happen in the dead tissue. However, you should protect your fish against the risk of a secondary infection that may occur, using specific medication (like Neosporin, Polysporin or Panalog).

Then, move the fish into an aquarium where you have already diluted methyl blue in the right concentration for long term baths (see the instructions).

The potassium permanganate, the metaphen, the copper sulphate, the formaldehyde, the neosporin are all substances which can prove to be efficient against this fungus.

The fish that have been serious affected by the disease should be eliminated in order to prevent the spread of the infection.

Maintaining a clean aquarium, at temperatures not very high, ensuring optimal living conditions for the fish e.g. correct filtration and oxygenation of the water, a high pH, depending of the necessities of each fish species in the aquarium, it’s the surest way to prevent branchiomyces.