In
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...
s, the coenosarc is the living tissue overlying the stony skeletal material of the coral. It secretes the
coenosteum In corals, the coenosteum is the stony skeletal material secreted by the coenosarc, the layer of living material lying between the corallites (the stony cups in which the polyps sit). The coenosteum is composed of aragonite
Aragonite is a carbo ...
, the layer of skeletal material lying between the
corallite
A corallite is the skeletal cup, formed by an individual stony coral polyp, in which the polyp sits and into which it can retract. The cup is composed of aragonite, a crystalline form of calcium carbonate, and is secreted by the polyp. Corallit ...
s (the stony cups in which the
polyps sit). The coensarc is composed of
mesogloea
Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges.
Descr ...
between two thin layers of
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
and is continuous with the body wall of the polyps.
The coenosarc contains the gastrovascular canal system that links the polyps and allow them to share nutrients and symbiotic
zooxanthellae
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 ''Sy ...
.
References
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Cnidarian anatomy