What is Octocorallia?
Octocorallia meaning a subclass of the Anthozoa that contains the sea pens, sea pansies, sea fans, whip corals, and pipe corals. Octocorals always possess 8 tentacles and 8 complete septa (hard corals and anemones possess 12 or more tentacles and septa). They are colonial cnidarians whose polyps are connected by a tissue mass called the coenenchyme. This tissue connects the gastrovascular (digestive) cavities of all the polyps in the colony
An octocorallian (sea fan) with brain coral (sceractinian) in the foreground.
reference: Coral Reef Information System – GlossaryWhat is