Polypodium hydriforme

Polypodium hydriforme
Two specimens of free-living Polypodium
Scientific classification
Kingdom: Animalia
Phylum: Cnidaria
Subphylum: Endocnidozoa
Class: Polypodiozoa
Raikova, 1988
Order: Polypodiidea
Poche, 1914
Family: Polypodiidae
Poche, 1914
Genus: Polypodium
Ussov, 1885
Species:
P. hydriforme
Binomial name
Polypodium hydriforme
(Ussov, 1885)

Polypodium hydriforme is a species of Cnidarian that parasitizes in the eggs of sturgeon and similar fishes (Acipenseridae and Polyodontidae). It is one of few animals that lives inside the cells of other animals. P. hydriforme is the only species in the class Polypodiozoa.