Costia or Ichthyobodo
Ichthyobodo or Costia parasites are protozoa, a single-celled moving organism of the flagellate category. Ichthyobodo parasites can proliferate very quickly on the skin of fish. In the initial stage the disorder is difficult to recognize, because the parasites involved are tiny organisms. Their size varies between 15 and 20 μm. Just compare the thickness of a human hair is about 50 μm (=0,05 mm). Sometimes grey patches will form on the skin of fish attacked. Besides they may start swinging in the water and start rubbing. A Ichthyobodo parasite is one of the most dangerous protozoa for koi. Increase in number of Costia can proceed incredibly quickly, whereas symptoms may fail to appear for a long time.
Treating Costia or Ichthyobodo
Ichtyobodo may spread very quickly in water an attack other fish. It is wise to put diseased fish in quarantine outside the pond. Quick treatment is necessary to avoid massive death of fish. This is possible, applying a fast acting means against single-celled parasites. Additional feed should administered, using quality feed, whereas pond water should be filtered, using a filter provided with activated carbon. This is important to prevent Ichthyobodo .