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.
Improve water quality.
Fa-Hui Tang et al.
Dr. Chacko, Jim
Unity College of Maine
Fish Patholgy Dept.