#polypodiozoa

Polypodiozoa. This class contains only one species, P. hydriforme, which is one of the few animal parasites that lives inside the cells of other animals (fish)

Octocorallia. This class is made up of aquatic colonial animals with 8-fold symmetry. It includes soft corals and sea pens.

Polypodium hydriforme

...is a species of parasitic cnidarian that attacks the eggs of sturgeon and paddlefish. P.hydriforme is a intracellular parasite and spends most of its life inside the oocytes of fish in this time it will develop from a binucleated cell to a inside-out larva and then it will form into an elongated stolon. Prior to spawning P.hydriforme will evert to a normal position and eventually will leave the host cell. Once they emerge the stolons will break up into individual fragments that will multiply, grow sexual organs and infect another host.

Phylogeny

Animalia-Cnidaria-Polypodiozoa-Polypodiidae-Polypodium-P.hydriforme