''Acropora polystoma'' is a species of acroporid

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 ...

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 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, ...

on the

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 biol ...

, 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 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 re ...

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 of randomly positioned spinules. It is similar to ''

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 ...

'' and other species of the ''robusta'' group. It is found in marine environments in tropical, shallow reefs, at depths between . It occurs on slopes of reefs damaged by strong waves, and reef edges. It is composed of

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 prec ...

(calcium carbonate).

Distribution

''Acropora polystoma'' is uncommon and found over a large area; the Gulf of Aden, the Indian Ocean, the Indo-Pacific, Southeast Asia, Australia, and the western Pacific. The species also occurs in Japan, American Samoa, the Cook Islands, and five regions of Indonesia. It spawns in October in the French Polynesia. It is threatened by reef destruction, climate change, rising sea temperatures leading to bleaching, coral disease, being prey to starfish ''Acanthaster planci'', and human activity and infrastructure. It is listed as a vulnerable species on the IUCN Red List, is under CITES Appendix II, and might be found in Marine Protected Areas.

Taxonomy

It was first described by G. Brook in 1891 as ''Madrepora polystoma''.

References

{{Taxonbar, from=Q3955637 Acropora Corals described in 1891 Vulnerable animals