White Spot Disease or Ich (Ichthyophthiriasis )

KPD-57
Ich, also called white spot disease, is one of the most common protozoan infections affecting aquarium and pond fishes. This brief overview of the life cycle will help the aquarist and pond keeper understand more about the problem and assist them in properly treating their fishes. The term "Ich" comes from the generic name Ichthyophthirius of the species multifilis, which is the freshwater form of white spot disease. The marine protozoan causing white spot disease is Cryptocaryon irritans.

The most common way of diagnosing ich is by close observation of the infected fishes. The presence of small, (.5 to 1.0 mm) white dots scattered about on the fishes' skin. This is not always proof that the fish is infected with ich as several other infections can have a similar appearance. Proof positive can be obtained by removing one of the spots and observing it under a microscope. Ich has a small micronucleus and a prominant crescent-shaped macronucleus.

Ich is most often introduced into the aquarium or pond by adding new fishes or aquatic plants. Tomites which have only recently attached themselves to the host will not be readily visable. It is good aquarium and pond keeping practice to isolate any new fishes for at least four days under close observation. For tropical fishes, maintain a temperature of around 75° F (24° C). Check carefully for the presence of any tell-tale white spots appearing on the skin of the fishes and treat them accordingly. If no white spots are observed on tropical fishes within four days at this temperature, they can be moved from isolation. Remember, fishes maintained at cooler water temperatures (such as pond fishes) will require longer isolation times.

The visable stages of Ich are carried out within the host fishes' skin. The first stages are called trophozoites and are highly resistant to drug therapy. Trophozoites mature into trophonts and leave the host, falling to the bottom of the aquarium or pond.These mature trophonts release from 200 to 1,000 tomites. These tomites move about looking for a host, which they must find within 2 to 3 days at 75° F (24° C) or they will die. Cooler temperatures will lengthen this time. It is this free swimming stage that is most vulnerable to treatment. It is important to note that these intermediate stages may also attach themselves to plants and be accidentally introduced into an aquaruim or pond along with the new plants. Once the tomite attaches to the host, it matures and the cycle begins anew.


A= The trophozoites in the host's skin. B= Trophont leaving the host. C= The mature trophont with hundreds of maturing tomites. D= The realeasing of tomites that penetrate the skin of the host fish

The best treatment in the Kordon product line for either fresh or saltwater fishes is Rid-Ich+ followed by Malachite Green. Kordon products that are suitable for use in a separate bath to destroy the tomites of freshwater Ich are Formalin-3, Malachite Green, Methylene Blue and Permoxyn. For a bath, the fishes must be removed from the original aquarium or pond and placed in a separate aquarium or tank for a treatment time of a minimum of 6 days, or three days longer than the last observed spots. All of these treatments can be harmful to invertebrates and some are also harmful to the nitrifying bacteria of the biological filter bed, so appropriate precautions should be taken. Treatment instructions are given under the individual Product Data Sheets for each of the recommended products. Experiments have shown that the use of ultraviolet light (UV) filtration is effective in controlling the free swimming stages of freshwater Ich. The minimum lethal dose for the tomites is 100,000 microwatts per second per square meter.

NOTE: During the breeding season many male freshwater cyprinid fishes, such as carp, goldfish and barbs, will develop small lumps (often with whitish tips) on their gill covers and elsewhere on their heads. These are not signs of a parasite infestation, but a normal manifestation for these fishes

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