Fish White Spot

Fish white spot disease or Ich is the most commonly occurring disease in freshwater fish.



It results due to infection by a protozoan parasite. This parasite is round in shape and covered by hair-like extensions known as cilia. Understanding the life cycle of this parasite is important as this will help to determine which action needs to carried out to deal with the problem. The life cycle can be accelerated by regulating the temperature of the water in the tank.



There is an infecting phase and a free phase in the life cycle of the parasite. In the infecting phase, the parasite feeds on the host and cysts occur in the form of white spots. During this time the parasite grows and matures. Then it exits the host and reproduces asexually.



The offspring that result then go off in search for other hosts.

As the parasite burrows into the body of the fish, it begins to feed on its blood. It may also affect the gills of the fish. The infection is usually detected when small white spots on fish appear. The fish may also appear ill and may hold its fins close to the body. It may also try and rub and scratch against the sides of the aquarium or decorations in order to relieve the irritation caused by the burrowing of the parasite. If the gills become affected, the fish may also start gasping for air. Other fish white spot symptoms may also include lethargy, lying on the bottom of the tank, lack of response during feeding, remaining in a corner of the tank and swimming with clamps up.

Fish white spot treatment must be done during the free phase as this is the time when new parasites will be produced. The parasite cannot be killed during the infecting phase since it is encysted and remains unaffected by medication. This phase can continue for a few weeks even. It is advisable to speed up the infecting phase as this will reduce the amount of exposure of the host to the parasite. In the free phase, as many parasites as possible must be exposed to the medication. For optimal treatment, the water in tropical aquariums must be increased to about 30 degrees and in cold water aquariums, up to 22 degrees. This increase in temperature must be done gradually to make it easier for the fish. Fish white spot disease must be treated properly as if left untreated; it can contribute to secondary bacterial infections.