Trichodina
It attacks both skin and gill tissues of our Koi, and can often cause more damage to gills than realized.
Classed as a warm water parasite, it can survive for some time without a host. It causes vegetation of the skin giving rise to a grey white opaque appearance on the body of infected Koi which exhibit the classic symptoms of flashing, rubbing and lethargy.
A magnification of 100 to 200 x is required to view this parasite.
Recommended treatments are Potassium Permanganate.