A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles.
Corals are colonial 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.
Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.
Antipatharians, also known as black corals or thorn corals, are an order of soft deep-water corals. These corals can be recognized by their jet-black or dark brown chitin skeletons, which are surrounded by their colored polyps. Antipatharians are a cosmopolitan order, existing in nearly every oceanic location and depth, with the sole exception of brackish waters. However, they are most frequently found on continental slopes under 50 m (164 ft) deep. A black coral reproduces both sexually and asexually throughout its lifetime. Many black corals provide housing, shelter, food, and protection for other animals.
Zoanthids are an order of cnidarians commonly found in coral reefs, the deep sea and many other marine environments around the world. These animals come in a variety of different colonizing formations and in numerous different colors. They can be found as individual polyps, attached by a fleshy stolon or a mat that can be created from small pieces of sediment, sand and rock. The term "zoanthid" refers to all animals within this order Zoantharia, and should not be confused with "Zoanthus", which is one genus within Zoantharia.
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.
Bamboo coral, family Isididae, is a family of mostly deep-sea coral of the phylum Cnidaria. It is a commonly recognized inhabitant of the deep sea, due to the clearly articulated skeletons of the species. Deep water coral species such as this are especially affected by the practice of bottom trawling. These organisms may be an important environmental indicator in the study of long term climate change, as some specimens of bamboo coral have been discovered that are 4,000 years old.
Madrepora oculata, also called zigzag coral, is a stony coral that is found worldwide outside of the polar regions, growing in deep water at depths of 50 to at least 1500 meters. It was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. It is one of only 12 species of coral that are found worldwide, including in Subantarctic oceans. In some areas, such as in the Mediterranean Sea and the Northeast Atlantic Ocean, it dominates communities of coral. Due to their similar distribution and taxonomic relationship, M. oculata is often experimentally compared to related deep sea coral, Lophelia pertusa.
Parazoanthus axinellae, commonly known as the yellow cluster anemone, is a zoanthid coral found on the southern Atlantic coasts of Europe and in the Mediterranean Sea. Zoanthids differ from true sea anemones, in having a different internal anatomy and in forming true colonies in which the individual animals (polyps) are connected by a common tissue, called the coenenchyme.
Pavona duerdeni, the porkchop coral, is a coral that forms clusters of cream-colored lobes or discs. They grow in large colonies, divided into ridges or hillocks. The coral is considered to be uncommon due to its low confirmed abundance, yet they are more commonly found in Hawaii, the Indo-Pacific, and the Tropical Eastern Pacific. They make up some of the largest colonies of corals, and have a slow growth rate, as indicated by their dense skeletons. Their smooth appearance is due to their small corallites growing on their surface.
Alcyonium acaule or Mediterranean sea-finger is a species of soft coral in the family Alcyoniidae. It is found at moderate depths on shaded rocks in the Mediterranean Sea and adjoining parts of the Atlantic Ocean.
Palythoa is a genus of anthozoans in the order Zoantharia.
Carijoa riisei, the snowflake coral or branched pipe coral, is a species of soft coral in the family Clavulariidae. It was originally thought to have been native to the tropical western Atlantic Ocean and subsequently spread to other areas of the world such as Hawaii and the greater tropical Pacific, where it is regarded as an invasive species. The notion that it is native to the tropical western Atlantic was perpetuated from the fact that the type specimen, described by Duchassaing & Michelotti in 1860, was collected from the US Virgin Islands. It has subsequently been shown through molecular evidence that it is more likely that the species is in fact native to the Indo-Pacific and subsequently spread to the western tropical Atlantic most likely as a hull fouling species prior to its original description.
Brachycnemina is a suborder of zoanthids in the order Zoantharia. Genetic analysis has been used to suggest Brachycnemina is a monophyletic group diverging within the paraphyletic Macrocnemina.
Savalia savaglia, commonly known as gold coral, is a species of colonial false black coral in the family Parazoanthidae. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea where it often grows in association with a gorgonian. It is extremely long-lived, with a lifespan of 2,700 years, and develops into a large tree-like colony.
Porites cylindrica, commonly known as hump coral, is a stony coral belonging to the subclass Hexacorallia in the class Anthozoa. Hexacorallia differ from other subclasses in that they have 6 or fewer axes of symmetry. Members of this class possess colonial polyps which can be reef-building, secreting a calcium carbonate skeleton. They are dominant in both inshore reefs and midshelf reefs.
Callogorgia is a genus of deep sea corals that are ideally suited to be habitats for different organisms. They reproduce both sexually and asexually, clinging to the hard substrate of the ocean during their maturation process. Callogorgia are found at depths ranging from 750-8200 feet in the Gulf of Mexico, Pacific Ocean and the Caribbean Sea. An array of organisms have relationships with Callogorgia, including brittle stars, cat sharks, and copepods. The nature of these relationships are often commensal, with Callogorgia providing a habitat for the organisms.
Leiopathes glaberrima is a species of black coral of the order Antipatharia found in the northern Atlantic Ocean and the Mediterranean Seas deep water habitats. A very slow-growing species, it is among the oldest living animals on the planet.
Narella is a genus of deep-sea soft corals in the family Primnoidae (Milne Edwards, 1857). They are sessile, bottom-dwelling organisms that can be found in all ocean basins, having cosmopolitan distribution. They have a branching appearance.
Tubastraea micranthus, commonly known as the black sun coral, is a coral from the Tubastraea genus, which comprises the sun corals. They have a dark green color and they grow and branch out in bush/tree like colonies. The habitat of T. micranthus ranges from the Red Sea to Madagascar, and into the Pacific as far as Fiji. It has been observed in waters as shallow as 4m to a depth of 138m in the new habitat. It is notable though, that in its native habitats Tubastraea micranthus has only been found at depths up to 50 meters and any discovered at lower depths are in invasive environments. Furthermore, there have been obscure sightings of Tubastraea micranthus in Korea.
