Trichodoniasis (<i>Trichodinella</i>)


Grey/blue tone of skin
Skin colour is a grey/blue tone.
Pale slime film over skin
A slimy thin grey/white film covers the body.
Organic load high
Water has a high organic loading and an above normal BOD (Biological Oxygen Demand) reading.
Fins frayed or ragged
Fins look as if they are rotting away, giving eroded appearance.
Gills have excess mucous
Obvious slimy mucous is oozing from the gills of the fish.
Fish constantly rubs or scratches itself against any object available.
Skin excessive sliminess
Skin shows mucous and slime far in excess of normal.
Sluggish movements
Fish moves almost reluctantly in the water.
Ulcers - irregular
Irregular shaped ulcers are evident on the skin.
Bluish-white blotches on skin
Large patches of blue-grey matter evident on the skin of fish.


Unicellular parasites viz. Trichodina spp. and Trichodinella spp. Infestation spreads quickly to infect many fish. Very common. Seen from above they are circular, from the side they are bell shaped.The underside resembles a circular saw blade.


Easily cured once determination has been made. However parasite can live for some time free of host, and can also be carried on fish eggs so eradication must be extra thorough.

Mortalities reported but not fully evaluated.


Please login to see the treatment information.


Improve water quality.

DNA and RNA diagnostic references. 

Phylogenetic Analyses of Trichodinids ( Ciliophora, Oligohymenophora) inferred from18S rRNA Gene Sequence Data. 

From Curr Microbiol. 2013 Mar; 66 (3): 306-313

Fa-Hui Tang et al. The Key Laboratory of Animal Biology of Chongqing, Chongqing Normal
University, Chongqing, 400047 People's Republic of China.


Dr. Chacko, Jim
Unity College of Maine
Fish Patholgy Dept.


There are 5 disease pictures available. Please log in to see them.

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


There are 3 disease videos available. Please log in to see them. Protection Status