Octocorallia
Synonym: Alcyonaria.
Genera: 3000 species.
Zoology
Octocorallia are water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fans and sea whips). These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries.
Orders
Alcyonacea: soft corals.
Helioporacea
• Helioporidae
• Lithotelestidae
Pennatulacea: Sea pens
• Chunellidae
• Echinoptilidae
• Renillidae
• Scleroptilidae
• Stachyptilidae
Suborder Sessiliflorae
• Anthoptilidae
• Funiculinidae
• Kophobelemnidae
• Protoptilidae
• Umbellulidae
• Veretillidae
Suborder Subsessiliflorae
• Halipteridae
• Pennatulidae
• Virgulariidae
Octocorallia incertae sedis