Scleractinia

order of cnidarians

Scleractinia, also called stony corals or hard corals, an order in the Cnidaria. It contains the polyps which build most coral reefs.

Stony corals
Temporal range: Middle Triassic - Recent [1]
Scleractinian corals, illustration by
Ernst Haeckel, 1904
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Subclass: Hexacorallia
Order: Scleractinia
Bourne, 1900 [2]
Families

About 35, see text.

Synonyms
  • Madreporaria

Most of these corals are colonial. They secrete calcium carbonate, the base of every reef. Very often, the corals form a symbiosis with unicellular dinoflagellates. These zooxanthellae are usually of the genus Symbiodinium.

The closest relatives to stony corals are the sea anemones. Stony corals are only distantly related to fire corals and soft corals. There are about 1500 species, in 35 families.

References

change
  1. Stanley, G. D. The evolution of modern corals and their early history. Earth-Science Rev. 60, 195–225 (2003).
  2. Hoeksema, Bert (2015). "Scleractinia Bourne, 1900". WoRMS. World Register of Marine Species. Retrieved 2015-05-03.
 
Polyps of hard coral Favites come out at night to feed