The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.
As gorgonians (Gorgonacea), Horn coral or sea fans ( . Ez Gorgonie ; rare Gorgonia ) are a group of similar coral from the subclass Octocorallia designated. The gorgonians do not form a monophyletic unit, but are only considered as a group because of their similar growth form and the skeleton made of the horn-like substance gorgonin . They were originally classified as an order to which two taxonomically recognized suborders ( Calcaxonia and Holaxonia ) and a group ( Scleraxonia ) belonged.
All gorgonians, like all their relatives from the subclass Alcyonaria, have polyps with eight pinnate tentacles . Horn corals live in all oceans from shallow water to the deep sea . A photo of the Titanic at a depth of 4,000 meters shows a gorgonian growing on the wreck. The coral reefs of the Caribbean are dominated by sea fans because they are particularly common there. Most of the species living in the Caribbean live in an endosymbiosis with unicellular, symbiotic algae ( zooxanthellae ).
- CORAL. Marine aquarium specialist magazine . No. 39 (June / July). Natur und Tier Verlag, Münster 2006. , ISSN 1439-779X
- Gorgonians in the sea water dictionary (German)
- Gorgonians in the Seawater Wiki (German)