Myxozoans

Myxozoans are a large group of spore-forming endoparasites of fish, amphibians, reptiles, some birds & mammals and aquatic invertebrates (worms and bryozoans). They are parasitic cnidarians - closely related to better-known species including corals, jellyfish and anemones. They are very common parasites of fish, although only a few species cause diseases of economic or ecological concern (including whirling disease, proliferative kidney disease, proliferative gill disease and soft-flesh disease).