Alcyonacea are an order of sessile colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Whilst not in a strict taxonomic sense, Alcyonacea are commonly known as soft corals. The term "soft coral" generally applies to organisms in the two orders Pennatulacea and Alcyonacea with their polyps embedded within a fleshy mass of coenenchymal tissue. Consequently, the term "gorgonian coral" is commonly handed to multiple species in the order Alcyonacea that produce a mineralized skeletal axis composed of calcite and the proteinaceous material gorgonin only and corresponds to only one of several families within the formally accepted taxon Gorgoniidae (Scleractinia). These can be found in order Malacalcyonacea (taxonomic synonyms of include : Alcyoniina, Holaxonia, Protoalcyonaria, Scleraxonia, and Stolonifera. They are sessile colonial cnidarians that are found throughout the oceans of the world, especially in the deep sea, polar waters, tropics and subtropics. Common names for subsets of this order are sea fans and sea whips; others are similar to the sea pens of related order Pennatulacea. Individual tiny polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan. Others may be whiplike, bushy, or even encrusting. A colony can be several feet high and across, but only a few inches thick. They may be brightly coloured, often purple, red, or yellow. Photosynthetic gorgonians can be successfully kept in captive aquaria.
Octocorallia is a class of Anthozoa comprising over 3,000 species of marine organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians within three orders: Alcyonacea, Helioporacea, and Pennatulacea. These organisms have an internal skeleton secreted by mesoglea and polyps with eight tentacles and eight mesentaries. As with all cnidarians these organisms have a complex life cycle including a motile phase when they are considered plankton and later characteristic sessile phase.
Bamboo coral, family Keratoisididae is a family of 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. Bamboo corals were previously defined to be the family Isididae, based on their articulated skeletons with proteinaceous joints, but this family was shown to be paraphyletic after it was found in 2021 that this had evolved at least five separate times. As of 2023, the taxonomy of bamboo corals is being actively revised.
Keratoisis is a genus of deep-sea bamboo coral in the family Keratosididae, containing the following species:
Scleraxonia is a suborder of corals, a member of the phylum Cnidaria.
Holaxonia is a suborder of soft corals, a member of the phylum Cnidaria. Members of this suborder are sometimes known as gorgonians and include the sea blades, the sea fans, the sea rods and the sea whips. These soft corals are colonial, sessile organisms and are generally tree-like in structure. They do not have a hard skeleton composed of calcium carbonate but have a firm but pliable, central axial skeleton composed of a fibrous protein called gorgonin embedded in a tissue matrix, the coenenchyme. In some genera this is permeated with a calcareous substance in the form of fused spicules. Members of this suborder are characterized by having an unspiculated axis and often a soft, chambered central core. The polyps have eight-fold symmetry and in many species, especially in the families Gorgoniidae and Plexauridae, contain symbiotic photosynthetic algae called zooxanthellae. These soft corals are popular in salt water aquaria.
Melithaea is a genus of octocorals in the family Melithaeidae. Members of the genus are commonly known as fan corals and are found in the tropical Indo-Pacific region. The type species is Melithaea ochracea.
Dendronephthya is a genus of soft corals in the family Nephtheidae. There are over 250 described species in this genus. They are sometimes kept in aquariums, but are notoriously difficult to keep, requiring a near constant supply of small foods such as phytoplankton.
Leptogorgia is a genus of soft coral in the family Gorgoniidae. The genus has a widespread distribution with members being found in the eastern Atlantic Ocean from Western Europe to South Africa, the Mediterranean Sea, the Atlantic coasts of North and South America, the Antilles and the Pacific coast of America. Species are found in both shallow and deep waters.
Antipathes is a genus of coral in the order Antipatharia, composed of black coral. Distinct features vary greatly within this genus: it contains symmetrically aligned as well as irregularly shaped corals, a range of different colors, and colonies that can be either sparsely branched or closely packed. polyps for these corals have six tentacles that are each lined with stinging cells. Unlike their reef-building cousins, these coral lack photosynthesizing algae and are not restricted to the lighter surface regions. They prefer to live in deeper waters near currents so they can catch and eat passing zooplankton.
Alcyonium is a genus of soft corals in the family Alcyoniidae and class octocorallia. Alcyonium generally called as dead men's finger.
Primnoidae is a family of soft corals.
Plexauridae is a family of marine colonial octocorals in the phylum Cnidaria. Members of this family are found in shallow tropical and subtropical seas. Many species contain symbiotic photosynthetic protists called zooxanthellae.
Siphonogorgia is a genus of soft corals in the family Nidaliidae. Like other members of this family, these corals do not contain symbiotic zooxanthellae.
Ellisella, commonly known as sea whip, is a genus of soft coral in the family Ellisellidae.
Clavularia is a genus of corals in the family Clavulariidae. They are often referred by the common names star polyps or clove polyps.
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.
Scleralcyonacea, previously referred to as Calcaxonia, is an order of soft corals in the class Octocorallia.
Villagorgia is a genus of gorgonian-type octocorals in the family Plexauridae.
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.
