The Myxozoa (etymology: Greek: myx- "slime" or "mucus" + zoa "animals") are a group of parasitic animals of aquatic environments. Over 1300 species have been described and many have a two-host lifecycle, involving a fish and an annelid worm or bryozoan. The average size of a Myxosporea spore usually ranges from 10μm to 20μm and Malacosporea up to 2mm. Infection occurs through valved spores. These contain one or two sporoblast cells and one or more polar capsules that contain filaments… (More on Myxozoa)