Trichodina
Trichodina is one of the easiest protozoan parasites to detect under the microscope as it is almost perfectly round with hundreds of hooks which resemble cilia found its periphery and it constantly rotates as it moves through the mucus, causing tissues damage.
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.
Trichodina is another small protozoan parasite which is commonly found on koi. Microscope identification is necessary, as it has an average size of 0.07mm in diameter.
This parasite is circular in appearance, and is often seen spinning and moving very quickly when viewed through the microscope. The parasite attaches to the koi using tiny hooks and holding discs.
The koi parasite Trichodina can quickly cause severe damage to the skin of a koi (as can all parasites) leaving the koi open to secondary infection from bacteria such as Aeromonas. Trichodina can swim well and therefore this koi parasite can quickly infest an entire pond of koi, especially when the stocking level of koi is high. Trichodina multiplies by division.
A magnification of 100 to 200 x is required to view this parasite.