Alcyoniidae is a family of
leathery or soft corals in the phylum
Cnidaria
Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...
.
[Leathery corals]
Wildsingapore.com (2010-02-28). Retrieved on 2013-09-17.
Description
A colony of leathery coral is stiff, hard and inflexible. It is composed of tiny polyps projecting from a shared leathery tissue. Members of the family may have two kinds of polyps; the autozooids have long trunks and eight tiny branched tentacles and project from the shared leathery tissue while the siphonozooids remain below the surface and pump water for the colony. They appear as tiny hollows or mounds among the taller autozooids. Different genera have different proportions of these two kinds of polyps. The autozooids only emerge when the colony is fully submerged.
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Distribution and habitat
Leathery corals occur globally in temperate and tropical seas. They are often pioneer reef species and are found in wave-exposed areas of reef crests, less turbid waters in lagoons, on steep slopes, under overhangs and at depths of thirty metres or even deeper.
Biology
Leathery coral polyps include endosymbiotic
An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root ...
algae called zooxanthellae
Zooxanthellae (; zooxanthella) is a colloquial term for single-celled photosynthetic organisms that are able to live in symbiosis with diverse marine invertebrates including corals, jellyfish, demosponges, and nudibranchs. Most known zooxanthell ...
. The algae undergo photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...
and produce sugars from sunlight. This food is shared with the host, which itself provides the algae with minerals and shelter. Periodically, the surface layer of the leathery tissue is shed. This seems to be a mechanism for ridding the colony of unwanted algal growth.[
In a study on the ]Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
, it was found that the population of these corals was very stable. There was little predation, low rates of growth, reproduction and mortality, few new colonies came into existence and few disappeared over a three-year period.[
]
Genera
The following genera are recognized in the family Alcyoniidae:Hedera
''Hedera'', commonly called ivy (plural ivies), is a genus of 12–15 species of evergreen climbing or ground-creeping woody plants in the family Araliaceae, native to Western Europe, Central Europe, Southern Europe, Macaronesia, northwestern ...
'' Conti-Jerpe & Freshwater, 2017
* '' Kotatea'' Kessel, Alderslade, Bilewitch, Schnabel, Norman, Tekaharoa Potts & Gardner, 2022
* '' Lateothela'' Moore, Alderslade & Miller, 2017
* '' Ushanaia'' Kessel, Alderslade, Bilewitch, Schnabel, Norman, Tekaharoa Potts & Gardner, 2022
See also
* '' Alcyonium digitatum''
* '' Alcyonium glomeratum''
References
{{Authority control
Alcyoniina
Cnidarian families