Porites lutea | |
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Porites lutea off Réunion | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Cnidaria |
Class: | Hexacorallia |
Order: | Scleractinia |
Family: | Poritidae |
Genus: | Porites |
Species: | P. lutea |
Binomial name | |
Porites lutea | |
Synonyms [2] | |
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Porites lutea is a species of stony coral in the family Poritidae. It is found growing in very shallow water on reefs in the Indo-Pacific region. It sometimes forms "microatolls" in the intertidal zone and these massive structures have been used to study trends in sea levels and sea water temperature.
Porites lutea forms massive, smooth, hemispherical mounds or helmet-shaped colonies up to 4 m (13 ft) across. The corallites have thin walls and are closely packed, some 1 to 1.5 mm (0.04 to 0.06 in) in diameter. In contrast to Porites lobata , the corallites are well-filled with skeletal elements, including five tall pali near the centre. The colour of this coral is usually cream or yellow, but other bright colours sometimes occur in shallow-water habitats. [3]
Porites lutea is native to the tropical Indo-Pacific region. Its range extends from Madagascar and the east coast of Africa to Malaysia, Indonesia, the Philippines, Japan and northern and eastern Australia. It occurs on back reef margins, in lagoons and on fringing reefs. It is a common species, often occurring with Porites australiensis and Porites lobata. [3]
This coral can form "microatolls" in the intertidal zone; these are disc-shaped mounds with dead coral material at the top and living material round the perimeter which continues to grow sideways. [4] Sometimes these structures remain as fossil microatolls in which no living polyps survive but the colony morphology is retained. [4] Fossil microatolls of Porites lutea, combined with precise dating of individual annual growth rings using the uranium–thorium dating method, allows these structures to be used to determine past relative changes in sea-level. [5] Their use for this purpose on reefs in the South China Sea has shown that during the period 7000–6550 years before 2000, the sea level was about 170 to 220 centimetres (67 to 87 in) higher than now, with four or more cycles of fluctuations. [5]
In Yemen, the non-native, invasive, encrusting red sponge Clathria aceratoobtusa grows over the surface of the coral, at the rate of about 1 cm (0.4 in) per month, smothering and killing it. A thin white line of dead tissue separates the healthy coral tissues from the advancing sponge. [6]
Sometimes fragments of Porites lutea become detached from colonies. These may remain alive and end up further down the reef slope, or moved to a new location by currents or waves; in this way new colonies or even new reefs may form in locations unsuitable for larval settlement. [7]
The growth rate of corals is influenced by environmental conditions; massive corals lay down a band of calcium carbonate each year, and the thickness of the band indicates the rate of growth. Researchers in Indonesia have studied the growth rate of Porites lutea and correlated it with the El Niño phenomenon. Growth rates were higher on windward slopes with greater wave action, and lower on lee slopes with less water movement. Rates were at their highest in 1992, when the sea temperature was about 28 °C (82 °F), and at their lowest in 1998 when it was 29.6 °C (85.3 °F). The correlation between water temperature and growth rate was complex, but in general growth rates of the coral were lower when the coral was stressed by higher water temperatures. [8]
Exposure of Porites lutea to increased concentration of iron causes bleaching through loss of symbiotic zooxanthellae; however the effect is less marked in corals previously exposed to raised levels of iron, suggesting the development of tolerance to the metal. [9]
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 secrete calcium carbonate to form a hard skeleton.
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.
Mussidae is a family of stony coral in the order Scleractinia. Following a taxonomic revision in 2012, the family is now restricted to species found in the Atlantic Ocean, with Pacific species transferred to the new family Lobophylliidae. Many species are referred to as brain coral because their generally spheroid form and grooved surface resembles the convolutions of a brain.
Porites is a genus of stony coral; they are small polyp stony (SPS) corals. They are characterised by a finger-like morphology. Members of this genus have widely spaced calices, a well-developed wall reticulum and are bilaterally symmetrical. Porites, particularly Porites lutea, often form microatolls. Corals of the genus Porites also often serve as hosts for Christmas tree worms.
A microatoll is a circular colony of coral, dead on the top but living around the perimeter. Growth is mainly lateral, as upward growth is limited by exposure to air. Microatolls may be up to 6 meters (20 ft) in diameter. They are named for their resemblance to island atolls formed during the subsidence of volcanic islands, as originally suggested by Darwin (1842).
Porites astreoides, commonly known as mustard hill coral or yellow porites, is a colonial species of stony coral in the family Poritidae.
Porites lobata, known by the common name lobe coral, is a species of stony coral in the family Poritidae. It is found growing on coral reefs in tropical parts of the Indian and Pacific Oceans.
Isastrea is an extinct genus of corals that lived during the Jurassic and Cretaceous periods. Its fossils have been found in Europe, Africa, North America, Asia and South America.
Colpophyllia is a genus of stony corals in the family Mussidae. It is monotypic with a single species, Colpophyllia natans, commonly known as boulder brain coral or large-grooved brain coral. It inhabits the slopes and tops of reefs, to a maximum depth of fifty metres. It is characterised by large, domed colonies, which may be up to two metres across, and by the meandering network of ridges and valleys on its surface. The ridges are usually brown with a single groove, and the valleys may be tan, green, or white and are uniform in width, typically 2 centimetres. The polyps only extend their tentacles at night.
Dichocoenia is a monotypic genus of stony coral in the family Meandrinidae. It is represented by a single species, Dichocoenia stokesii, which is commonly known as pineapple coral, elliptical star coral, or pancake star coral. It is found in the Caribbean Sea and the western Atlantic Ocean. Dichocoenia stokesii has irregular calyces and its form can be either a massive, hemispherical hump or a flat, platform-like structure.
Alveopora spongiosa is a species of stony coral that is found in the Red Sea, the Gulf of Aden, the southwest and northern Indian Ocean, the central Indo-Pacific, Australia, Southeast Asia Japan, the East China Sea and the oceanic west and central Pacific Ocean. It can be found on protected upper coral reef slopes, generally from depth of 9–20 m, but can grow at depths of up to 50 m. It is moderately susceptible to coral bleaching, and is harvested for the aquarium trade.
Turbinaria mesenterina, commonly known as disc coral, is a species of colonial stony coral in the family Dendrophylliidae. It is native to the Indo-Pacific region. The International Union for Conservation of Nature has rated its conservation status as being "vulnerable".
Coelastrea aspera is a species of stony coral in the family Merulinidae. It is a colonial species native to the Indo-Pacific region where it occurs in shallow water. It was first described by the American zoologist Addison Emery Verrill in 1866 as Goniastrea aspera but it has since been determined that it should be in a different genus and its scientific name has been changed to Coelastrea aspera. This is a common species throughout much of its wide range and the International Union for Conservation of Nature has rated its conservation status as being of "least concern".
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.
Acropora pharaonis is a species of acroporid coral that was first described by Milne-Edwards and Haime in 1860. Found in marine, tropical, reefs on slopes sheltered from wave action, it occurs at depths of between 5 and 25 m. It is classed as a vulnerable species on the IUCN Red List, and it has a decreasing population. It is common and found over a large area and is classified under CITES Appendix II.
Oulophyllia crispa, sometimes called the intermediate valley coral, is a species of stony coral in the family Merulinidae. It is native to the tropical western and central Indo-Pacific region. Although this coral has a wide range, it is generally uncommon and seems to be decreasing in abundance, and the International Union for Conservation of Nature has rated its conservation status as being "near threatened".
Euphylliidae are known as a family of polyped stony corals under the order Scleractinia.
Manicina areolata, commonly known as rose coral, is a colonial species of stony coral. It occurs in shallow water in the West Atlantic Ocean and Caribbean Sea, sometimes as small solid heads and sometimes as unattached cone-shaped forms.
Clathria aceratoobtusa is a species of sponge in the family Microcionidae. The genus Clathria is subdivided into a number of subgenera, and it is in the subgenus Microciona. It is native to shallow water habitats in the Indo-Pacific region. The type locality is the Gulf of Thailand.