Cnidaria Octocorallia



Calcigorgia spiculifera
Class Anthozoa - Subclass Octocorallia - Order Gorgonacea - Suborder Holaxonia - Family Acanthogorgiidae
image copyright © Keith Clements and Jon Gross Marine Life of the Northeast Pacific

In this group of mostly soft corals, the polyps are almost always formed into colonies, each polyp having eight pinnate (side- branching) tentacles. Octocorallians include a number of diverse forms

Subclass Octocorallia: Octocorals. Eight mesenteries. Order Gorgonacea: Sea fans, sea whips Order Telestacea Order Pennatulacea: Sea pens, sea pansies Order Alcyonaea: Soft corals Order Helioporacea Order Stolonifera: Organ pipe corals (among others)

Alcyonacea - sometimes known as 'soft corals'. Often inhabit low tidal zone of rocky shores

Gorgonacea - members secrete a horny material called gorgonin to act as skeletal support. Abundant on coral reefs, especially in the Caribbean.

■──○Alcyonaria ├─○Protoalcyonaria │ ├─Haimeidae │ └─Taiaroidae ├─○Stolonifera │ ├─Clavulariidae │ ├─Cornulariidae │ └─Tubiporidae ├─○Telestacea │ ├─Coelogorgiidae │ ├─Pseudocladochonidae │ └─Telestidae ├─○Gastraxonacea │ └─Pseudogorgiidae* ├─○Gorgonacea │ ├─○Holaxonia │ │ ├─Acanthogorgiidae │ │ ├─Ainigmaptilidae │ │ ├─Chrysogorgiidae │ │ ├─Ellisellidae │ │ ├─Gorgoniidae │ │ ├─Ifalukellidae │ │ ├─Isididae │ │ ├─Keroeididae │ │ ├─Paramuriceidae │ │ ├─Plexauridae │ │ └─Primnoidae │ └─○Scleraxonia │ ├─Anthothelidae │ ├─Briareidae │ ├─Coralliidae │ ├─Melithaeidae │ ├─Paragorgiidae │ ├─Parisididae │ └─Subergorgiidae ├─○Alcyonacea │ ├─Alcyoniidae │ ├─Astrospiculariidae │ ├─Maasellidae │ ├─Nephtheidae │ ├─Siphonogorgiidae │ └─Xeniidae ├?─Pennatulacea └─○Helioporacea ├─Helioporidae └─Lithotelestidae

Pennatulacea - the sea pens, have a single long main polyp forms a stalk which anchors the colony in its mud substrate. Branches from this bear the feeding and ciliated polyps and generate an inward current of water that keeps the whole colony inflated. It used to be thought that some Edicarian forms were sea-pens, this does not seem to be the case.

See also Race Rocks - Ptilosarcus gurneyi - for more on the Sea Pens.

──○Pennatulacea ├─○Sessiliflorae │ ├─Anthoptilidae │ ├─Chunellidae │ ├─Echinoptilidae │ ├─Funiculinidae │ ├─Kophobelemnidae │ ├─Protoptilidae │ ├─Renillidae │ ├─Scleroptilidae │ ├─Stachyptilidae │ ├─Umbellulidae │ └─Veretillidae └─○Subselliflorae ├─Pennatulidae ├─Pteroeididae └─Virgulariidae

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page uploaded 16 June 2002, last modified 2 May 2003
(originally uploaded on Kheper Site 3 June 1999)
checked ATW050611
page by M. Alan Kazlev (Creative Commons License)
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