Polypodium (animal)

Taxobox
name = "Polypodium"
regnum = Animalia
phylum = Cnidaria
classis = Polypodiozoa
classis_authority = Raikova, 1994
familia = Polypodiidae
genus = "Polypodium"
species = "P. hydriforme"
binomial = "Polypodium hydriforme"
binomial_authority = (Ussov, 1885)

"Polypodium" is a monotypic genus of strange parasitic animals; the only genus in family Polypodiidae. "Polypodium hydriforme" is a parasite of the eggs of sturgeon and similar fishes (Acipenseridae and Polyodontidae). It is one of few metazoans living inside the cells of other animals.

The taxonomic position of Polypodium is unclear. It was formerly classified as Narcomedusae, but is now treated as its own class Polypodiozoa, most often placed in the cnidarians. Based on 18S rRNA DNA sequence analysis, a relationship with Myxozoa has been proposed (Zrzavý & Hypša 2003), but this is controversial. If correct, "P. hydriforme" could be united with the Myxozoa in a clade Endocnidozoa.

References

* (2003): Myxozoa, "Polypodium", and the origin of the Bilateria: The phylogenetic position of "Endocnidozoa" in light of the rediscovery of "Buddenbrockia". "Cladistics" 19(2): 164–169. doi|10.1111/j.1096-0031.2003.tb00305.x (HTML abstract)