Acropora Temporal range: | |
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Acropora pulchra | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Cnidaria |
Class: | Hexacorallia |
Order: | Scleractinia |
Family: | Acroporidae |
Genus: | Acropora Oken, 1815 [2] |
Species | |
See text | |
Synonyms | |
List
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Acropora is a genus of small polyp stony coral in the phylum Cnidaria. [3] Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described. [4] Acropora species are some of the major reef corals responsible for building the immense calcium carbonate substructure that supports the thin living skin of a reef.
Depending on the species and location, Acropora species may grow as plates or slender or broad branches. Like other corals, Acropora corals are colonies of individual polyps, which are about 2 mm across and share tissue and a nerve net. The polyps can withdraw back into the coral in response to movement or disturbance by potential predators, but when undisturbed, they protrude slightly. The polyps typically extend further at night to help capture plankton and organic matter from the water.
The species are distributed in the Indo-Pacific (over 100 species) and Caribbean (3 species). However, the true number of species is unknown: firstly, the validity of many of these species is questioned as some have been shown to represent hybrids, for example Acropora prolifera; [5] and secondly, some species have been shown to represent cryptic species complexes. [6]
Symbiodinium , symbiotic algae, live in the corals' cells and produce energy for the animals through photosynthesis. Environmental destruction has led to a dwindling of populations of Acropora, along with other coral species. Acropora is especially susceptible to bleaching when stressed. Bleaching is due to the loss of the coral's zooxanthellae, which are a golden-brown color. Bleached corals are stark white and may die if new Symbiodinium cells cannot be assimilated. Common causes of bleaching and coral death include pollution, abnormally warm water temperatures, increased ocean acidification, sedimentation, and eutrophication.
In 2014 the U.S. Fish and Wildlife Service listed ten Acropora species as 'threatened'. [7]
Most Acropora species are brown or green, but a few are brightly colored, and those rare corals are prized by aquarists. Captive propagation of Acropora is widespread in the reef-keeping community. Given the right conditions, many Acropora species grow quickly, and individual colonies can exceed a meter across in the wild. In a well-maintained reef aquarium, finger-sized fragments can grow into medicine ball-sized colonies in one to two years. Captive specimens are steadily undergoing changes due to selection which enable them to thrive in the home aquarium. In some cases, fragments of captive specimens are used to repopulate barren reefs in the wild. [8]
Acropora species are challenging to keep in a home aquarium. They require bright light, stable temperatures, regular addition of calcium and alkalinity supplements, and clean, turbulent water.
Common parasites of colonies in reef aquariums are "Acropora-eating flatworms" Amakusaplana acroporae, [9] and "red bugs" ( Tegastes acroporanus ).
The following species are recognised in the genus Acropora: [10]
Brain coral is a common name given to various corals in the families Mussidae and Merulinidae, so called due to their generally spheroid shape and grooved surface which resembles a brain. Each head of coral is formed by a colony of genetically identical polyps which secrete a hard skeleton of calcium carbonate; this makes them important coral reef builders like other stony corals in the order Scleractinia. Brain corals are found in shallow warm water coral reefs in all the world's oceans. They are part of the phylum Cnidaria, in a class called Anthozoa or "flower animals". The lifespan of the largest brain corals is 900 years. Colonies can grow as large as 1.8 m (6 ft) or more in height.
Montipora is a genus of Scleractinian corals in the phylum Cnidaria. Members of the genus Montipora may exhibit many different growth morphologies. With eighty five known species, Montipora is the second most species rich coral genus after Acropora.
Fire corals (Millepora) are a genus of colonial marine organisms that exhibit physical characteristics similar to that of coral. The name coral is somewhat misleading, as fire corals are not true corals but are instead more closely related to Hydra and other hydrozoans, making them hydrocorals. They make up the only genus in the monotypic family Milleporidae.
The Fungiidae are a family of Cnidaria, commonly known as mushroom corals or plate corals. The family contains thirteen extant genera. They range from solitary corals to colonial species. Some genera such as Cycloseris and Fungia are solitary organisms, Polyphyllia consists of a single organism with multiple mouths, and Ctenactis and Herpolitha might be considered as solitary organisms with multiple mouths or a colony of individuals, each with its separate mouth.
The Caryophylliidae are a family of stony corals found from the tropics to temperate seas, and from shallow to very deep water.
Acanthastrea is a genus of large polyp stony corals in the family Lobophylliidae. The colonies are massive and usually flat. The corallites are either circular or angular in shape. The septa are thick near the wall of the corallite, becoming thin near the columella, and have tall teeth. The polyps are extended only at night.
Goniopora, often called flowerpot coral, is a genus of colonial stony coral found in lagoons and turbid water conditions. Goniopora have numerous daisy-like polyps that extend outward from the base, each tipped with 24 stinging tentacles which surrounds a mouth.
Pocillopora is a genus of stony corals in the family Pocilloporidae occurring in the Pacific and Indian Oceans. They are commonly called cauliflower corals and brush corals.
Cycloseris is a genus of solitary disc corals in the family Fungiidae. They are found in the Indo-Pacific. They inhabit the lower reef slopes, and the areas between reefs with soft sediments. They tolerate turbid waters.
Lobophyllia, commonly called lobed brain coral or lobo coral, is a genus of large polyp stony corals. Members of this genus are sometimes found in reef aquariums.
Pavona is a genus of colonial stony corals in the family Agariciidae. These corals are found in shallow waters in the Indo-Pacific region.
Alveopora is a genus of colonial stony corals in the family Acroporidae. Members of this genus are native to the Indo-Pacific region and are often found on reef slopes in turbid water. They are generally uncommon.
Echinopora is a genus of stony corals in the family Merulinidae.
Merulinidae is a family of reef-building stony corals.
Favites is a genus of stony corals in the family Merulinidae. Members of this genus are native to the Indo-Pacific region and their ranges extend from the Red Sea through the Indian Ocean and Western Pacific Ocean as far as Japan, the Line Islands and the Tuamotu Islands.
Dipsastraea is a genus of stony corals in the family Merulinidae. Members of this genus are native to the Indo-Pacific region. They are zooxanthellate corals.
Acropora elegans is a species of acroporid coral that was first described by Henri Milne-Edwards in 1860. Found in sheltered, sloping reefs, this species occurs at 30 to 60 m depth. The species is listed as vulnerable on the IUCN Red List, and has a decreasing population. It is not common and has a small range, and is listed under CITES Appendix II. It is more resistant to disease than other Acropora species.
Leptastrea is a genus of massive reef building stony corals known primarily from the Indo-Pacific. Although previously assigned to Faviidae, Budd et al. (2012) assigned it to Scleractinia incertae sedis based on phylogenetic results demonstrating the polyphyly of Faviidae. Assigned to family Leptastreidae by Rowlett (2020).
Heterocyathus is a genus of coral of the family Caryophylliidae.