''Porites astreoides'', commonly known as mustard hill coral or yellow porites, is a

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 au ...

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 ...

Poritidae Poritidae is a family of stony corals. Members of the family are colonial hermatypic (reef-building) corals. They are variable in size and form but most are massive, laminar or ramose as well as branching and encrusting. The corallites are compa ...

. It is a common species in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and western tropical Atlantic Ocean in North, Central, and South America; and the eastern tropical Atlantic Ocean in western Africa.

Description

When it grows in fast-flowing, shallow water, ''Porites astreoides'' is encrusting but in calmer water at medium depths it is a massive coral with a smooth, mounded, semi-spherical form and can grow to in diameter. At greater depths it is usually plate-like and in caves and under overhangs the plates are angled to receive the maximum amount of light. It is the only species within the genus ''

Porites ''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 symmetric ...

'' not to have a finger-like form. 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 small and tightly-packed and give the coral a porous appearance. The polyps each have six

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s and are generally retracted during the day. This coral is yellow, yellowish-green, pale grey or pale brown, a colour given to it by the dinoflagellate

zooxanthellae 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 ...

, microscopic algae that live

symbiotically Symbiosis (from Ancient Greek, Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different Organism, biological organisms, be it Mutualism (biolog ...

within the coral's tissue.

Distribution and habitat

''Porites astreoides'' is found growing in shallow water on reefs in the Caribbean Sea and in the western-central and southwestern Atlantic Ocean in the Caribbean region and tropical North America, Central America, and South America; and the eastern-central Atlantic Ocean in tropical western Africa. IUCN Red List ver 3.1: ''Porites astreoides''

Least Concern species 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 ...

(2008) . accessed 2017-06-27. It is a common species on all parts of a reef and in lagoons. It usually grows in water less than deep but may occasionally be found at depths of up to . It is sometimes free-living, growing on loose bits of coral, pebbles or mollusc shells. Large domed colonies sometimes appear to be separated into several lobes. This happens when part of the coral has died, and the living tissue in between the dead patches continues to develop, giving a clumped effect.

Biology

The polyps of ''Porites astreoides'' feed mostly at night, extending their tentacles to catch

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

. The coral also obtains an important part of its nutritional needs as a result of the

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

performed by the zooxanthellae in sunlight. Some colonies of ''Porites astreoides'' are female while others are

hermaphroditic 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 taxonomic groups of animals (mostly invertebrates) do not have separ ...

. Sexual reproduction occurs with male gametes being released into the sea around the time of the new moon. The sperm gets drawn into other polyps where fertilization takes place. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e are initially brooded but are liberated into the sea at about the time of the full moon. The

planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which ...

larvae then drift with the currents for some time before settling onto the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

and metamorphosing into new polyps. Each of these grows into a new colony by secreting a

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

skeleton and

budding Budding or blastogenesis is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. For example, the small bulb-like projection coming out from the yeast cell is know ...

. This is initially extratentacular budding, taking place at the side of the polyp, but at a later stage in the development of the colony, the budding is intratentacular, taking place within the ring of tentacles.

Ecology

''Porites astreoides'' often has the sponge ''

Mycale laevis ''Mycale laevis'', the orange icing sponge or orange undercoat sponge, is a species of marine demosponge in the family Mycalidae. ''Mycale'' is a large genus and this species is placed in the subgenus ''Mycale'' making its full name, ''Mycale (M ...

'', with prominent osculi, growing on its underside. This coral is also often associated with

fan worm Sabellida is an order of annelid worms in the class Polychaeta. They are filter feeders with no buccal organ. The prostomium is fused with the peristomium and bears a ring of feathery feeding tentacles. They live in parchment-like tubes made of p ...

s. The polyps contain stinging cells known as

nematocyst A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

s to try to ward off the

stoplight parrotfish The stoplight parrotfish (''Sparisoma viride'') is a species of marine ray-finned fish, a parrotfish from the family Scaridae, inhabiting coral reefs in Florida, Caribbean Sea, Gulf of Mexico, Bermuda and as far south as Brazil. It mainly feeds ...

, other reef fish,

snails A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastrop ...

worms Worms may refer to: *Worm, an invertebrate animal with a tube-like body and no limbs Places *Worms, Germany, a city **Worms (electoral district) *Worms, Nebraska, U.S. *Worms im Veltlintal, the German name for Bormio, Italy Arts and entertainme ...

and

starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...

that feed on it. It is also important to the coral to be in an unshaded position where its zooxanthellae can function fully. Sedimentation may limit this but under good conditions, this coral can grow at the rate of about per year. The

IUCN Red List of Threatened Species 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 biologi ...

ranks this coral 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 ...

" as, within its range, it is widespread and common. Compared to other members of its genus, it is resistant to disease and

bleaching Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...

and lives in deeper water so may be less affected by rising sea temperatures.

References

External links

{{Taxonbar, from=Q3333980 Poritidae Cnidarians of the Atlantic Ocean Cnidarians of the Caribbean Sea Marine fauna of Africa Marine fauna of North America Marine fauna of South America Invertebrates of Central America Biota of the Gulf of Mexico Fauna of Brazil Fauna of Mexico Fauna of the Southeastern United States Fauna of Venezuela Least concern biota of Africa Least concern biota of North America Least concern biota of South America Least concern biota of the United States Corals described in 1816 Taxa named by Jean-Baptiste Lamarck