Ichthyophthirius multifilis (Ich, White Spot) - Koi Parasite

Ichthyophthirius multifilis also known as Ich or white spot disease. It's a parasite of koi fish. Ich probably the most well known koi fish parasite in the world. An Ich infestation is easily recognized by the tell tale white spots that appear all over a koi fish. The white spots look very similar to tiny salt granuals, peppered all over a Koi fish. Theront is the name for the white spots. It is called a Trophont, when the Theront detaches and sinks to the bottom of a pond or tank. That are called Tomites, when Trophont then seperates into hundreds of new parasites. The Tomites then look for a Koi attach to and repeat the life cycle. Like any other parasite, Ich can cause a secondary infection to koi fish like Aeromonas.