Tropical Fish Site

Profiles Reviews Guides for Tropical and Marine

Gill Mites Fish Disease

Fish that are already infested by gill mites are brought into aquariums. The tiny mites stay on the fish’s gills, and attack the fish by feeding on blood and living flesh.


  • Gasping at the water’s surface
  • Gill covers that are partially open


Initial treatment with sterazin is recommended with a secondary treatment of octozin to cure the fish once the mites are gone and help the gills get back to normal.


It is often advised that you should keep tropical fish in a quarantine tank before introducing them to your main tank. Although this wont prevent gill mites in the fish you may have purchased with the disease, it will stop it spreading to your other fish if you are able to observe them and treat them before introducing to your main aquarium.

Tropical Fish Site takes no responsibility for diagnosing the exact problem with your tropical fish, this is purely meant as a guide only. Be sure to look at other common tropical fish diseases to ensure you have made the correct diagnosis as there is often crossover between them.