Some protozoans, however, live in or on your salmon fry. They are invisible to the naked eye. Death, reduced feeding activity, flashing, changes in tissue structure, slow growth and reduced stamina are all signs of potential protozoan disease in your fish. The infected fish try to close up their fins and rub against hard objects. The parasites show up as white, pinhead-size specks on the fins and body.
Costia is another variation of a protozoan disease.
This parasite attacks the gills. The symptoms are much the same as Ich. Virus The Department of Fisheries is very concerned about the spread of viral diseases. The state requires that you disinfect any egg transfers to your aquari um. The earliest sign of IHN is the presence of long, opaque, off-white fecal casts tailing from the anus of the fry.