(phylum Protozoa, subphylum Cnidospora)
A class of protozoa, which parasitize invertebrates and lower vertebrates, particularly fish, often with fatal consequences for the host. The spores contain a coiled polar filament. When a spore is ingested by a new host the filament is extruded and attaches the spore to the gut wall of the host. There are three orders.
Subjects: Zoology and Animal Sciences.