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Acropora Polystoma
''Acropora polystoma'' is a species of acroporid coral that was first described by G. Brook in 1891. Found in marine, tropical, reefs on upper slopes where waves are strong, it occurs at depths between . It is classed as a vulnerable species on the IUCN Red List, and it has a decreasing population. It is not common and found over a large area and is classified under CITES Appendix II. Description ''Acropora polystoma'' is found in colonies of clumps or of corymbose plates with diameters not exceeding . The branchlets have lengths of up to and diameters of between . It is blue, cream, yellow, lavender, or brown in colour, and the branches are similar in size and become thinner towards the ends. The branches contain axial and radial corallites. Axial corallites are located on the ends of the branch tips, and are small with outer diameters of between and inner diameters of . Radial corallites are regularly arranged and found in rows, and are tube-shaped. It contains a small number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acroporidae
Acroporidae is a family of small polyped stony corals in the phylum Cnidaria. The name is derived from the Greek ''"akron"'' meaning "summit" and refers to the presence of a corallite at the tip of each branch of coral. They are commonly known as staghorn corals and are grown in aquaria by reef hobbyists. Description Staghorn corals are the dominant group of reef builders. They come in many shapes and sizes and can be highly variable in colour and form, even within the same species. Most are either a branching variant or a wall/ table top variant shaped and some are encrusting. Encrusting means they grow over rock structure. the Their colours vary between browns, whites, pinks, blues, yellows, greens and purple, depending not only on species but also on the growing conditions. Identification is difficult and requires close examination of the corallites and a biochemical and genetic analysis. There is a corallite at the tip of each branch and, with the exception of ''Astreopora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 secrete calcium carbonate to form a hard skeleton. A coral "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulnerable Species
A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, threatening its survival and reproduction improve. Vulnerability is mainly caused by habitat loss or destruction of the species' home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity (animal), captivity, an example being the military macaw. There are currently 5196 animals and 6789 plants classified as Vulnerable, compared with 1998 levels of 2815 and 3222, respectively. Practices such as cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically. Criteria The International Union for Conservation of Nature uses several criteria to enter species in this category. A tax ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corymbose
Corymb is a botanical term for an inflorescence with the flowers growing in such a fashion that the outermost are borne on longer pedicels than the inner, bringing all flowers up to a common level. A corymb has a flattish top with a superficial resemblance towards an umbel, and may have a branching structure similar to a panicle. Flowers in a corymb structure can either be parallel, or alternate, and form in either a convex, or flat form. Many species in the Maloideae, such as hawthorns and rowans, produce their flowers in corymbs. The Norway maple and yerba maté are also examples of corymbs. The word ''corymb'' is derived from the Ancient Greek word ''korymbos'' meaning "bunch of flowers or fruit". Image:Schirmtraube (inflorescence).svg, Racemose corymb Image:Schleifenblume06.jpg, ''Iberis umbellata'' or candytuft (racemose corymb) Image:Schirmrispe (inflorescence).svg, Cymose corymb Image:Sambucus nigra 003.jpg, ''Sambucus nigra ''Sambucus nigra'' is a species complex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acropora Massawensis
''Acropora polystoma'' is a species of acroporid coral that was first described by G. Brook in 1891. Found in marine, tropical, reefs on upper slopes where waves are strong, it occurs at depths between . It is classed as a vulnerable species on the IUCN Red List, and it has a decreasing population. It is not common and found over a large area and is classified under CITES Appendix II. Description ''Acropora polystoma'' is found in colonies of clumps or of corymbose plates with diameters not exceeding . The branchlets have lengths of up to and diameters of between . It is blue, cream, yellow, lavender, or brown in colour, and the branches are similar in size and become thinner towards the ends. The branches contain axial and radial corallites. Axial corallites are located on the ends of the branch tips, and are small with outer diameters of between and inner diameters of . Radial corallites are regularly arranged and found in rows, and are tube-shaped. It contains a small number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aragonite
Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments. The crystal lattice of aragonite differs from that of calcite, resulting in a different crystal shape, an orthorhombic crystal system with acicular crystal. Repeated twinning results in pseudo-hexagonal forms. Aragonite may be columnar or fibrous, occasionally in branching helictitic forms called ''flos-ferri'' ("flowers of iron") from their association with the ores at the Carinthian iron mines. Occurrence The type location for aragonite is Molina de Aragón in the Province of Guadalajara in Castilla-La Mancha, Spain, for which it was named in 1797. Aragonite is found in this locality as cyclic twins inside gypsum and marls of the Keuper facies of the Triassic. This type of arago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acropora
''Acropora'' is a genus of small polyp stony coral in the phylum Cnidaria. Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described. ''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. Anatomy and distribution 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). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corals Described In 1891
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 "group" is a colony of very many genetically identical polyps. Each polyp is a sac-like animal typically only a few millimeters in diameter and a few centimeters in height. A set of tentacles surround a central mouth opening. Each polyp excretes an exoskeleton near the base. Over many generations, the colony thus creates a skeleton characteristic of the species which can measure up to several meters in size. Individual colonies grow by asexual reproduction of polyps. Corals also breed sexually by spawning: polyps of the same species release gametes simultaneously overnight, often around a full moon. Fertilized eggs form planulae, a mobile early form of the coral polyp which, when matu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
