Symptoms:

• Darting around tank or rubbing against glass or ornaments. I mistook this for chasing a reflection.
• Excess mucus
• White or gray film over fish may be only on gills
• Labored breathing
• Lethargy

What is it?

Chilodonella is a ciliated protozoan which means it is a one celled creature with whip-like appendages used for swimming.

How did it get there?

If the water temperature is too low or a fish is stressed, the chilodonella protozoa will take this opportunity to attack the skin and gills. This is a highly contagious disease, and care should be made to not pass it to other tanks, and to thoroughly clean all equipment. If fish is affected in a community tank, treat the entire tank.

Treatment

Many medications that treat for Ich/ick can be used to treat for chilodonella. Active ingredients in these medications are malachite green (Maracide), or formalin (Formalin-3). Raising the temperature to 80F (26.7C) will help with treatment. Make sure when raising the temperature to only raise 1 to 2 degrees an hour so as not to stress your already sick fish. The temperature should be kept as steady as possible.

Prevention

• Like many diseases, this is caused by stress from either poor water quality, fluctuating temperatures, or even a change in tank. Keeping your water clean and your temperature at a steady 76-82F (24.4-27.8C) will help decrease stress in your fish. Use of aquarium salt will aid your fish in developing a protection against disease and injury.