Octocorallia

views updated May 09 2018

Octocorallia (Alcyonaria; phylum Cnidaria, class Anthozoa) A subclass of sedentary, colonial corals with polyps that always have eight tentacles which are almost invariably pinnate. There are eight complete, unpaired mesenteries and septa, and a ventral groove on the stomodaeum. Skeletal structures are usually made from calcareous spicules.

Octocorallia

views updated May 08 2018

Octocorallia (octocorals) A subclass of the class Anthozoa, poorly known in the fossil record, that ranges from Ordovician to Recent. The colony is shaped like a flat fan of interconnecting branches from which project tubes with many zooids. Heliopora is an important reef former. The pennatulaceans (Pennatulacea) are also octocorals.

octocorals

views updated May 08 2018

octocorals See OCTOCORALLIA.

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