Costia- Costia is liable to affect goldfish. Costia (Ichthyobodo) is a microscopic protozoan flagellate. A microscope is needed to see it clearly. The organism attaches itself to the fish and destroys skin cells. It usually preys on fish that are already ill, or weakened. This is seen in overcrowded tanks. In ponds it is seen in the spring. While the parasite is attached to the fish it will thrive. If the parasite falls from the fish it will die within an hour. When the infestation begins fish are liable to die within a few days if treatment is not administered.
Symptoms: Red hemorrhaging will appear usually under the chin and along the fish's back. If the red dots are under the scales it is more than likely a bacterial infection. Affected fish will swim awkwardly, with their fins folded. They may seem to be scratching themselves against objects in the tank. An off-white film over the body with reddening of the most affected areas may be seen upon closer inspection.
Treatment: The best treatment is to raise the water's temperature to 770F where the parasite will be unhappy and to 860F where they will die. This may be a dangerous task if the fish are suffering from a severe infestation. Putting your fish in a 3% salt dip until they roll over (then quickly put them back in the tank) or a 1% salt bath for 20 minutes may work. There are anti-parasite medications available at the local pet stores. Follow directions on the packages. If using Quick Cure do not use the high temperature treatment or salt. This will kill your fish!
