''Cladocora caespitosa'', commonly known as cushion coral, is a

stony coral Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a ...

of the subclass

Hexacorallia Hexacorallia is a Class (biology), class of Anthozoa comprising approximately 4,300 species of aquatic organisms formed of polyp (zoology), polyps, generally with 6-fold symmetry. It includes all of the stony corals, most of which are Colony (b ...

. This species forms the only true coral reef in the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

Description

The polyps are a clear maroon colour, around 5 mm in diameter and form cushion-shaped colonies, in symbiosis with

Zooxanthella Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''Symbi ...

algae. They produce deposits of calcium carbonate which form the calciate structures in which they live. It is the largest stony coral in the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

, reaching up to 50 cm in diameter. ''C. caespitosa'' has an average generation length of about 30 years.

Distribution and habitat

This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Mediterranean Sea, where it is attested already in the Upper

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Mljet Mljet (; la, Melita, it, Meleda) is the southernmost and easternmost of the larger Adriatic islands of the Dalmatia region of Croatia. The National Park includes the western part of the island, Veliko jezero, Malo jezero, Soline Bay and a sea be ...

island, Croatia, there is a small

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Co ...

made up of ''C. caespitosa''. It was believed to be the only true coral reef in the Mediterranean. Recent findings in the Adriatic Sea show that Cladocora c. is not the only one reef building specie of the Mediterranean Sea. Cladocora caespitosa Maratea

Reproduction

The colonies grow through

budding Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is know ...

, but the species spreads through the settlement of plankton-like larva on seabed suited to colonisation.

Threats

''Cladocora caespitosa'' is classified as endangered under the

IUCN red list The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

, mostly based on recent mass die-offs caused by heat wave events in the Mediterranean.

References

Bibliography

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External links

* {{Taxonbar, from=Q3678817 Scleractinia Corals described in 1758 Taxa named by Carl Linnaeus