Goldfish White Spot Disease
Symptoms of Goldfish White Spot Disease
Small white spots (giving the disease it's name) which look like nodules of salt attached to the fish on the skin, gills and fins. Fish can sometimes be observed rubbing against hard or sharp objects, whilst trying to dislodge the parasitic nodules. In the latter stages the fish may be observed gasping for oxygen. This is because severe infection of the gills will reduce the fishes ability to absorb oxygen naturally.
Causes of Goldfish White Spot Disease
White spot or whitespot disease (also known as ich) is severely contagious and is caused by the protozoan parasite - ichthyophthirius multifiliis. This parasite attaches itself to fish as part of its lifecycle, burrowing underneath the skin to feed on the fish, forming the characteristic white spots or cystic nodules at each place of infection. The parasitic nodules eventually fall off the fish but the parasite continues to multiply inside the nodule. The nodule eventually bursts releasing free swimming infectious parasites into the water which attach themselves to new host fish. White Spot is often introduced with new unquarantined fish which are already carrying the disease. It is widely believed that fish become prone to white spot infection when water temperature fluctuates widely or when temperatures dip below the normal.
Treatment of Goldfish White Spot Disease
When treating white spot it is recommended to increase the water temperature as this accelerates the life cycle of the parasites which can only be treated during the free swimming stage of the life cycle. Increased temperature reduces disolved oxygen levels so try to make sure the water is well aereated. For coldwater goldfish it is not recommended to raise the temperature beyond around 25oC (77oF).
The main treatment types for curing white spot are usually based on malachite green, formalin, copper or aquarium salts. As with all things opinions vary on which is the more effective. We recommend promptly treating with a commercial anti-parasite medication. Commercial remedies are Maracide by Mardel Labs and Protozin by Waterlife. Some resistant strains of the white spot parasite seemed to have developed, which can be difficult to treat. If the treatment used is not effective within 7-10 days then you will need to try an alternative treatment method.