''Trichodina'' species are '''ciliated protozoan parasites''' of marine and freshwater species of fish. In large numbers they can cause '''skin and gill disease''' and can ultimately lead to the death of the fish. | ''Trichodina'' species are '''ciliated protozoan parasites''' of marine and freshwater species of fish. In large numbers they can cause '''skin and gill disease''' and can ultimately lead to the death of the fish. |