The parasite
Ichthyophthirius causes the
fish disease commonly known as Ick, which can infect and damage the
skin,
gills, and/or
eyes of many species of fish.
The parasite's life cycle is simple: trophozoites are found in pustules on the fish and escape when the pustules rupture. The trophozoites settle to the substrate, form a cyst, and reproduce asexually. The cyst, now containing hundreds of "swarmers" (or tomites), breaks open, and the swarmers search for a new host. The swarmer burrows into the new host's tissue and grows into a new pustule.
This parasite is found on many species of fish under natural conditions, but it is a particularly serious parasite under conditions of confinement and high population density (i.e., fishponds and aquariums).
Symptoms:
Ick first appears as a few small white dots on the fins or body. As the disease spreads, the fish will appear to have been sprinkled with salt. Other symptoms may include fish scratching against gravel, rapid breathing, cloudy eyes, cloudy fins and fin deterioration.
How To Avoid Ick:
Stress lowers the fish’s immune system which can lead to various diseases, including Ick. A healthy aquarium is subject to Ick when a new fish (directly from the pet shop) introduces it to a healthy tank. Live foods can bring about Ick. Unclean water conditions, an improper diet, or overcrowding, can also contribute to the spread of this disease.
How To Treat Ick:
It is always best to remove the infected fish and place in a smaller "hospital" tank. If this is not possible, it is necessary to medicate the main tank.
The most common external parasitic control drugs packaged for use are Aureomycin, Malachite Green, Benzaldehyde, quinine hydrochloride, and quinine sulfate. Turn off all aquarium lights and keep the aquarium as dark as possible. Increase aeration to ease breathing problems, and increase tank temperature slowly to about 85 degrees, at the rate of one degree every five hours. Maintain conditions for at least ten days.