Gill flukes (<i>Dactylogyrus</i>)


Abnormal swimming - streaks
Fish swims in short bursts, then stops.
Gills are partly protruded
Parts of the gills are protruding in abnormal manner.
Gills extended wide
Gills are flared open extended almost to right angle to body.
Hanging at surface
Fish stays at water surface all the time.
Fish constantly rubs or scratches itself against any object available.
Respiration rapid
Fish is breathing very fast, much faster than is normal.
Fish has a continuous "coughing" action.
Growth poor
Parasite infested fish show very slow or no growth, as parasite is taking the food.
Muscular atrophy
Muscles of fish show evident wasting away.
Breathing at surface
Fish stays at surface usually at an inclined angle and breathes or sucks air.
Reluctant to feed
Fish comes to eat but with evident lack of appetite.
Gills have excess mucous
Obvious slimy mucous is oozing from the gills of the fish.


A monogenetic trematode. Several species affect fish. These parasites tear out small pieces of the gills of the fish, causing tremendous damage. Can also be found on the skin, in lesser numbers. Usually when fish are crowded. They have a direct life cycle. Parasite can complete its entire life cycle on a single host.


Treatment is specific and effective. Outlook good if correctly diagnosed. Badly affected fish will seldom recover properly.


Please login to see the treatment information.


Improve water quality, keep bottom of tanks clean, reduce stock density.

DNA and RNA diagnostic references. 

Ribosomal DNA and morphological analysis of Dactylogyrus species from freshwater fishes of India

From Journal of Parasitical Diseases  Oct.2011 201-214 . 
Prapunjika Sharma et al. 


Dr. Jacobs, Bruno
Fish Medical sprl
Esneux   Belgium


There are 7 disease pictures available. Please log in to see them.

Login has failed
Login has failed
Don't have an account? Register here


There are 4 disease videos available. Please log in to see them. Protection Status