Precious coral
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Precious coral ( Corallium rubrum ) |
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| Scientific name | ||||||||||||
| Corallium rubrum | ||||||||||||
| Linnaeus , 1758 |
The precious coral ( Corallium rubrum ), also known as red coral , is an octocoral resembling the gorgonian from the western and central Mediterranean and the adjacent eastern Atlantic on the coasts of Portugal and Morocco , near the Canary and Cape Verde Islands . It lives at depths of 2 to 280 meters, in shallower water only in the shade in caves and under overhangs.
features
Like almost all octocorals , the precious coral forms colonies that consist of many individual polyps . The colonies are between 5 and 30 cm in size and are irregular and sparsely branched, with continuous strong currents the coral also forms crusts. Colonies over one meter in size and weighing up to 30 kilograms have disappeared due to over-exploitation for jewelry making. The ends of the branches are 3 to 5 mm thick, the base of large colonies can be up to 3 cm thick. The chalky branches of the colony are formed from fused sclerites . The living coenenchyme is vermilion, dark red to bright red, more rarely also pink or white in color and contrasts clearly with the white, more or less transparent polyps that have eight feathered tentacles. Precious coral colonies only grow 2 to 8 mm per year.
The precious coral can be confused with the crust- forming leather coral ( Parerythropodium coralloides ) and some bog animals such as the false coral ( Myriapora truncata ) or the moose antler bog animal ( Schizotheca serratimargo ). However, the former does not have its own limestone skeleton, but covers dead gorgonians, the latter are orange in color and have branch ends that look like they have been cut off.
Way of life
The precious coral is shy of light and grows above all below a depth of 40 meters, to a depth of over 100 meters (maximum 280 m), less often in shallower water in the protection of caves. Freestanding, in low light, without the protection of overhangs or in crevices, it occurs only below a depth of 80 meters. The precious coral feeds on zooplankton . Precious corals are colonized by various boring sponges .
In most cases, precious coral colonies are sexually separated. The egg cells are fertilized in the female polyp, develop there to the planular larva , are then expelled and live planktonic for a few days until they settle on a solid surface. The planular larva then changes to the primary polyp, which continues to multiply by budding and form a new colony.
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use
The lime axis of the precious coral is used to make jewelry . The center of jewelry production is Torre del Greco , near Naples . Today precious corals are mainly "fished" by divers off Corsica , Sardinia and Tunisia , in 2010 over 500 tons.
literature
- Matthias Bergbauer, Bernd Humberg: What lives in the Mediterranean? 1999, Franckh-Kosmos Verlag, ISBN 3-440-07733-0
- Steven Weinberg: Mediterranean , Delius Klasing, 1996, ISBN 3-7688-0968-4
Web links
- Food and Agriculture Organization of the United Nations: Species Fact Sheets: Corallium rubrum (Linnaeus, 1758).
Individual evidence
- ↑ Classification, treatment methods and species protection in decorative corals , website of the EPI - Institute for Gemstone Testing