Costia or Ichthyobodo

Costia or Ichthyobodo parasites are protozoa, single-celled moving organism of the flagellate category. Ichthyobodo parasites can multiply very rapidly on the skin of the fish. In the early stages, the disease is difficult to recognize because these parasites are very small. The size varies between 15 and 20 μm. Just compare, the thickness of a human hair is about 50 μm (= 0.05 mm). Sometimes gray spots appear on the skin of the fish. In addition, the fish may start rocking in the water and scrape along the shore or over the bottom. This parasite is one of the most dangerous protozoa for koi. The multiplication can be incredibly fast, while symptoms may not appear for a long time.

Treating Costia or Ichthyobodo

Costia – Ichtyobodo can spread very quickly in the water and affect other fish. It is wise to place the sick fish in a quarantine tank outside the pond. Prompt treatment is necessary to prevent mass fish deaths. This can be done with a fast-acting agent against single-cell parasites. Supplementary feeding, i.e. giving extra food, with a good quality food and filtering the pond water with a filter equipped with activated carbon is very important to prevent costia.