''Favites pentagona'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

stony coral Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Merulinidae Merulinidae is a family of reef-building stony corals. Characteristics All the genera in this family are colonial, reef-building corals. Skeletal structures are similar to those of Faviidae but are highly fused, without paliform lobes. The vall ...

, sometimes known as larger star coral. It is native to the Indo-Pacific region and its range extends from the Red Sea through the Indian Ocean to the Western Pacific Ocean. This is a common species throughout its wide range and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has rated its conservation status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

Description

Colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

of ''Favites pentagona'' are encrusting or massive, sometimes with lobes forming irregular columns. The colony may spread to about a metre (yard) across. The

corallite A corallite is the skeletal cup, formed by an individual stony coral polyp, in which the polyp sits and into which it can retract. The cup is composed of aragonite, a crystalline form of calcium carbonate, and is secreted by the polyp. Corallit ...

s are less than in diameter. The corallite walls are sharply-angled and thin, and several polyps may share a common wall. The palliform lobes are clearly visible on the oral disc and there are a small number of

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

. This coral is often vividly coloured, with contrasting (often green) oral discs and brown, red or purple

coenosarc In corals, the coenosarc is the living tissue overlying the stony skeletal material of the coral. It secretes the coenosteum, the layer of skeletal material lying between the corallites (the stony cups in which the polyps sit). The coensarc is comp ...

, the living tissue that covers the skeleton between the polyps.

Distribution

''Favites pentagona'' is native to the Indo-Pacific region where it occurs in shallow tropical and subtropical seas. Its range extends from the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...

and South Africa to India, Indonesia, Japan and Australia, where it occurs both in

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

and 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, ...

. Its depth range is down to and it is common on rocky reefs, outer reef channels, reef slopes and lagoons.

Ecology

''Favites pentagona'' is a

zooxanthellate Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''Sy ...

species of coral. This means that it harbours

symbiotic Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

unicellular

dinoflagellate The dinoflagellates (Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...

s in its tissues, which use the energy from sunlight to synthesize nutrients, from which the host coral benefits. It is an aggressive species of coral. At night it extends its polyps to feed on

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

, and expands its elongated sweeper tentacles armed with stinging cells well beyond the limits of its base, so as to avoid being crowded or overgrown by other organisms. It clears away sand that settles on its surface by inflating its polyps to dislodge the sediment. ''F. pentagona'' is a simultaneous

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

, the eggs and sperm being released in well-formed bundles. In any one area, spawning tends to occur in synchrony, with all the corals liberating their

gamete A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...

bundles at the same time. These rise to the sea surface and float, thus maximising the chance of successful fertilisation. ''F. pentagona'' is susceptible to

black band disease Black band disease is a coral disease in which corals develop a black band. It is characterized by complete tissue degradation due to a pathogenic microbial consortium. The mat is present between apparently healthy coral tissue and freshly expo ...

and white plague, two coral diseases which have become more common since the 1990s.

Status

''Favites pentagona'' has a very wide range and is common over much of that range. There is no precise information on population trends but this coral faces the same threats as other species;

global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

ocean acidification Ocean acidification is the reduction in the pH value of the Earth’s ocean. Between 1751 and 2021, the average pH value of the ocean surface has decreased from approximately 8.25 to 8.14. The root cause of ocean acidification is carbon dioxid ...

and degradation of its coral reef habitats. The

has assessed its conservation status as being of "

References

{{Taxonbar, from=Q3941859 Merulinidae Corals described in 1795