Xenia (coral)
| Xenia | ||||||||||||
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Xenia sp. |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Xenia | ||||||||||||
| Lamarck , 1816 |
Xenia is a genus of octocorals from the coral reefs of the tropical Indo-Pacific and the Red Sea .
features
They are animal colonies that consist of many individual polyps . Xenia species have a soft, short trunk, very slimy due to secretions, and non-retractable, monomorphic polyps. Some species also grow crust-shaped. As with all genera from the subclass Octocorallia, the single polyp has eight pinnate tentacles. The sclerites of Xenia in the shape of tiny leaves. The color ranges from brown to beige to white. The polyps of many species perform characteristic pumping movements, through which the nutrients from the water are better distributed to all polyps and the oxygen is transported away from the coral tissue. The pulsating movements give the Xenia a selection advantage over other coral species. The photosynthesis of the symbiotic algae also produces oxygen radicals that damage the corals' metabolism. As the ocean warms, the radicals cause some corals to repel the symbiotic algae and die. By moving the Xenia, the radicals can be better transported away and therefore do not disturb the symbiosis.
All Xenia species live in a symbiosis with unicellular, symbiotic algae ( zooxanthellae ), from which they obtain most of the nutrients and oxygen they need. They also absorb organic substances from the surrounding water through the skin.
Xenia species can reproduce vegetatively very quickly and form large monospecific stocks in shallow water near the water surface.
literature
- Erhardt / Moosleitner: Mergus Sea Water Atlas Volume 2 , Mergus-Verlag, Melle, 1997, ISBN 3-88244-112-7
- Erhardt / Baensch: Mergus Sea Water Atlas Volume 5 , Mergus-Verlag, Melle, 2000, ISBN 3-88244-115-1
- Julian Sprung: Korallen , Dähne Verlag, 2000, ISBN 3-92168-487-0
- SA Fosså, & AJ Nilsen: Coral reef aquarium. Volume 4, Birgit Schmettkamp Verlag, ISBN 3-928819-05-4