Holaxonia

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Holaxonia
Pinnigorgia.jpg
Pinnigorgia sp.
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Alcyonacea
Suborder: Holaxonia
Studer, 1887
Families

See text

Paramuricea sp. Paramuricea copy.jpg
Paramuricea sp.
Eunicea sp. Eunicea sp. 02 by Line1.JPG
Eunicea sp.

Holaxonia is a suborder of soft corals, a member of the phylum Cnidaria. [1] 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. [2] 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. [3] [4]

Contents

Families and genera

The World Register of Marine Species list the following families and genera: [5]

See also

Related Research Articles

Scorpaeniformes Order of fishes

The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfish, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320.

Anthozoa Class of cnidarians without a medusa stage

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.

Sea pen Order of colonial marine cnidarians

Sea pens are colonial marine cnidarians belonging to the order Pennatulacea. There are 14 families within the order; 35 extant genera, and it is estimated that of 450 described species, around 200 are valid. Sea pens have a cosmopolitan distribution, being found in tropical and temperate waters worldwide, as well as from the intertidal to depths of more than 6100 m. Sea pens are grouped with the octocorals, together with sea whips (gorgonians).

Scleractinia Order of Hexacorallia which produce a massive stony 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.

Zoantharia Order of hexacorallians with marginal tentacles

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 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.

Alcyonacea Order of octocorals that do not produce massive calcium carbonate skeletons

Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different from "true" corals (Scleractinia). These can be found in suborders Holaxonia, 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 A subclass of Anthozoa with 8-fold symmetry

Octocorallia is a subclass of Anthozoa comprising around 3,000 species of water-based 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.

Scleraxonia Suborder of corals

Scleraxonia is a suborder of corals, a member of the phylum Cnidaria.

Melithaeidae Family of corals

Melithaeidae is a family of corals in the suborder Scleraxonia. Members of the family are commonly known as sea fans and are found on reefs in the tropical regions of the Indo-Pacific.

<i>Leptogorgia virgulata</i> Species of coral

Leptogorgia virgulata, commonly known as the sea whip or colorful sea whip, is a species of soft coral in the family Gorgoniidae.

<i>Millepora alcicornis</i> Species of hydrozoan

Millepora alcicornis, or sea ginger, is a species of colonial fire coral with a calcareous skeleton. It is found on shallow water coral reefs in the tropical west Atlantic Ocean. It shows a variety of different morphologies depending on its location. It feeds on plankton and derives part of its energy requirements from microalgae found within its tissues. It is an important member of the reef building community and subject to the same threats as other corals. It can cause painful stings to unwary divers.

<i>Gorgonia flabellum</i> Species of coral

Gorgonia flabellum, also known as the Venus fan, Venus sea fan, common sea fan, West Indian sea fan, and purple gorgonian seafan, is a species of sea fan, a sessile colonial soft coral.

<i>Leptogorgia hebes</i> Species of coral

Leptogorgia hebes, commonly known as the regal sea fan or false sea fan, is a species of soft coral in the family Gorgoniidae. It was formerly included in the genus Lophogorgia but that genus has been dismantled.

<i>Primnoa pacifica</i> Species of coral

Primnoa pacifica or red tree coral is a species of soft coral in the family Primnoidae. It is a deep water coral found in the North Pacific Ocean, and plays an integral role in supporting benthic ecosystems. Red tree corals grow axially and radially, producing structures of calcite and gorgonian skeletons that form dense thickets. Like other species of coral, red tree coral is made of a soluble form of calcium carbonate, which forms the reef structure, as well as provides food, shelter, and nutrients for surrounding organisms. Amongst the organisms red tree corals provide a home for, many are commercially important fish and crustaceans. These areas of marine habitat are listed as Habitat Areas of Particular Concern. However, anthropogenic impacts such as bottom trawling pose large-scale threats to these habitats. There are also concerns about the effects of ocean acidification on red tree coral, since it shares many of the same properties as other corals that are suffering from bleaching.

Stolonifera Suborder of soft corals in the order Alcyonacea

Stolonifera is a suborder of soft corals in the order Alcyonacea. Members of this taxon are characterised by having separate polyps budding off an encrusting horizontal, branching stolon. The skeletons include spicules or consists of a horny external cuticle. These soft corals are found in shallow tropical and temperate seas.

Nidaliidae Family of corals

Nidaliidae is a family of soft corals in the phylum Cnidaria. Some members of this family are similar in appearance to gorgonians. They are difficult to keep in the reef aquarium because they do not contain symbiotic zooxanthellae and therefore need to be fed on zooplankton. Others, in the genera Agaricoidea, Nidalla and Pieterfaurea, more resemble members of the family Nephtheidae and these are somewhat easier to keep in the aquarium.

<i>Eunicella cavolini</i> Species of coral

Eunicella cavolini, commonly known as the yellow gorgonian or yellow sea whip, is a species of colonial soft coral in the family Gorgoniidae. It is native to parts of the eastern Atlantic Ocean, Mediterranean Sea and Ionian Sea where it is a common species.

<i>Alcyonium coralloides</i> Species of coral

Alcyonium coralloides, commonly known as false coral, is a colonial species of soft coral in the family Alcyoniidae. It is native to the northeastern Atlantic Ocean and the Mediterranean Sea. In the former location it generally grows as sheets or small lobes but in the latter it is parasitic and overgrows sea fans.

<i>Savalia savaglia</i> Species of coral

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.

<i>Leiopathes glaberrima</i> Species of cnidarian

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.

References

  1. Holaxonia World Register of Marine Species. Retrieved 2011-12-03.
  2. Suborder Holaxonia Guide to the Shallow Water (0-200 m) Octocorals of the South Atlantic Bight. Retrieved 2011-12-05.
  3. Gorgonians (Holaxonia) Saltcorner. Retrieved 2011-12-03.
  4. Gorgonians Animal-World. Retrieved 2011-12-03.
  5. "WoRMS - World Register of Marine Species - Holaxonia". marinespecies.org. Retrieved 2018-03-30.