Coralite

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Recent azooxanthellae (which do not have zooxanthellae ) stony corals . Each picture above = view of the calyx with the clearly recognizable septa, underneath the colony .
In the mushroom coral Fungia scutaria you can see the septa of the corallite on a living specimen
"Brain Coral"
Diploria labyrinthiformis

A corallite or coral goblet is the part of the skeleton of stony corals (Scleractinia) on or in which the coral polyps sit. It is formed at the base of the polyp by the excretion of the finest aragonite crystals . The structure of the corallite reflects the anatomy of the coral polyp .

The chalice consists of a basal plate which is surrounded by an annular outer wall called theca . From the theca , six, twelve or, in the case of many large polyp hard corals, a multiple of six, sharp-edged calcareous septa extend radially to the center of the coralite. If the septa continue to the outside beyond the coral wall, the outer parts are called costae . The number of calcareous septa corresponds to the number of mesenteries in the gastric space of the polyps. In the center of the coralite, in some genera, there is a small pillar of lime called Collumella , to which all septa abut. In solitary corals often the outer wall is missing. The corallite continues to grow due to the lime production at the base of the polyp and gets deeper and deeper. If the septa and outer ring have become too high, a new basal plate, slightly higher than the old one, is formed. The old basal plate has now become a cross floor in coral skeleton, which Dissepiment is called. Living coral tissue that is underneath the new basal plate dies.

In the massive coral forms known as brain corals, the sinuous, strongly folded form arises from the fact that several polyps share an elongated coralite, and deep valleys are located between the common outer walls. This form is also called the Flabello-meandroid .

The exact fine structure of the coralites is an important feature in the very difficult identification of the hard coral species.

Individual evidence

  1. ↑ Daniel Knop : Reef aquariums for beginners. , ISBN 978-3944821191 , p. 163.

literature

  • Helmut Schumacher: Coral Reefs , BLV Verlagsgesellschaft München, 1988, ISBN 3-405-13614-8
  • Yossi Loya and Ramy Klein: Die Welt der Korallen , Jahr Verlag Hamburg, 1998, ISBN 3-86132-226-9

Web links