Trichodina is a circular shaped microscopic parasite. It looks like a flying saucer under a microscope. It spins and warbles very rapidly. Koi that have a Trichodina infestation usually start "flashing" in order to try to remove the source of irritation. Trichodina are asexual, the form of reproduction that they use is called Binary Fission. Binary Fission is kind of like the old bacteria cartoons where a single cell divides into two, the two splits into four and then so and and so forth. Trichodina infestations are usually removed by adding salt to a pond. Trichodina, like any other parasite, can cause a secondary infection like Aeromonas.
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