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.
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 mouth is fringed with tentacles. Although some species are solitary, most are colonial. The founding polyp settles and starts to secrete calcium carbonate to protect its soft body. Solitary corals can be as much as 25 cm (10 in) across but in colonial species the polyps are usually only a few millimetres in diameter. These polyps reproduce asexually by budding, but remain attached to each other, forming a multi-polyp colony of clones with a common skeleton, which may be up to several metres in diameter or height according to species.
Hexacorallia is a class of Anthozoa comprising approximately 4,300 species of aquatic organisms formed of polyps, generally with 6-fold symmetry. It includes all of the stony corals, most of which are colonial and reef-forming, as well as all sea anemones, and zoanthids, arranged within five extant orders. The hexacorallia are distinguished from another class of Anthozoa, Octocorallia, in having six or fewer axes of symmetry in their body structure; the tentacles are simple and unbranched and normally number more than eight. These organisms are formed of individual soft polyps which in some species live in colonies and can secrete a calcite skeleton. As with all Cnidarians, these organisms have a complex life cycle including a motile planktonic phase and a later characteristic sessile phase. Hexacorallia also include the significant extinct order of rugose corals.
Corynactis californica is a brightly colored colonial anthozoan corallimorph. Unlike the Atlantic true sea anemone, Actinia fragacea, that bears the same common name, strawberry anemone, this species is a member of the order Corallimorpharia, and is the only member found in the North American West Coast. Other common names include club-tipped anemone and strawberry corallimorpharian. The anemone can live up to at least 50 meters deep on vertical rock walls, and at the bottom of kelp forests. It is known to carpet the bottom of some areas, like Campbell River in British Columbia, and Monterey Bay in California.
Corallimorpharia is an order of marine cnidarians closely related to stony or reef building corals (Scleractinia). They occur in both temperate and tropical climates, although they are mostly tropical. Temperate forms tend to be very robust, with wide and long columns, whereas tropical forms tend to have very short columns with a wide oral disc and very short tentacles. The tentacles are usually arranged in rows radiating from the mouth. Many species occur together in large groups, although there are recorded instances of individuals. In many respects, they resemble the stony corals, except for the absence of a stony skeleton. Morphological and molecular evidence suggests that they are very closely related to stony corals.
Discosoma is a genus of cnidarians in the order Corallimorpharia. Common names for the genus include mushroom anemone, disc anemone and elephant ear mushroom.
Corynactis annulata, or the strawberry anemone, is a bright pink colonial anthozoan similar in body form to sea anemones and scleractinian stony corals. This species is a solitary animal of the order Corallimorpharia.
Corynactis is a genus of colonial anthozoans similar in appearance to sea anemones and in body format to scleractinian stony corals. These animals are cnidarians in the family Corallimorphidae. Large unidentified polyps of this genus feed on the crown-of-thorns seastar Acanthaster planci and may help control the crown-of-thorns population.
Corallimorphus is a genus of colonial anthozoans similar in appearance to sea anemones and in body format to scleractinian stony corals. These animals are cnidarians in the family Corallimorphidae. Members of the genus live off the Pacific coast of the US.
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.
Gemmocystis is a genus of apicomplexans.
Euphyllia cristata is commonly called grape coral. E. cristata is a kind of stony or hard coral in the family Euphylliidae; it also belongs to the genus Euphyllia in the order of Scleractinia. E. cristata has a wide range of distribution throughout the tropical waters of the Indo-West Pacific area with a large presence in Indonesia. However, despite this large range of distribution, E. cristata has a slightly lower abundance compared to other species, making them a little more uncommon to find. They are typically found in shallow waters from 1–35 meters deep.
Astrangia poculata, the northern star coral or northern cup coral, is a species of non-reefbuilding stony coral in the family Rhizangiidae. It is native to shallow water in the western Atlantic Ocean and the Caribbean Sea. It is also found on the western coast of Africa. The International Union for Conservation of Nature lists this coral as being of "least concern". Astrangia poculata is an emerging model organism for corals because it harbors a facultative photosymbiosis, is a calcifying coral, and has a large geographic range. Research on this emerging model system is showcased annually by the Astrangia Research Working Group, collaboratively hosted by Roger Williams University, Boston University, and Southern Connecticut State University
Oxypora glabra is a species of large polyp stony coral in the family Lobophylliidae. It is a colonial coral with thin encrusting laminae. It is native to the central Indo-Pacific.
Ricordea yuma is a species of coral in the family Ricordeidae, order Corallimorpharia; This order of corals do not produce the distinctive calcification of the closely related Scleractinian, or reef building corals. Ricordea yuma are found on the sea floor in relatively shallow, tropical or subtropical ocean environments. Distinctive features include a large mouth disk that takes up most of the organism, and brightly colored tentacles. Ricordea yuma can reproduce both sexually, and asexually by budding a new coral with replicated elements from the mother coral. This may be one mechanism of how they are able to spread and overtake areas rapidly; They have been observed being competitively successful at monopolizing areas by excluding reef-building coral species, after a disturbance in the substrate.
Corynactis viridis, the jewel anemone, is a brightly coloured anthozoan similar in body form to a sea anemone or a scleractinian coral polyp, but in the order Corallimorpharia. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea and was first described by the Irish naturalist George Allman in 1846.
Heterocyathus is a genus of coral of the family Caryophylliidae.
Heteropsammia is a genus of apozooxanthellate corals that belong to the family Dendrophylliidae.
