Plexaura homomalla

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Plexaura homomalla
Black sea rod Plexaura homomalla (4675579531).jpg
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Alcyonacea
Family: Plexauridae
Genus: Plexaura
Species:
P. homomalla
Binomial name
Plexaura homomalla
(Esper, 1792) [1]

Plexaura homomalla, commonly known as the black sea rod or Caribbean sea whip, is a species of gorgonian-type octocoral in the family Plexauridae. It is widely distributed in the Caribbean from the Florida Keys to the northern coast of Venezuela. P. homomalla contains the bioactive lipid prostaglandin A2 15-acetate methyl ester at about 3% of total wet weight.

Contents

Description

P. homomalla forms a bushy or candelabra-like colony of upright branches. It has a tendency to branch in a single plane with a few dichotomous forks, but mostly bears lateral branches. It grows to a height of about 35 cm (14 in) and has two forms; P. h. forma kuekenthali is taller and slimmer, with narrow terminal branches, and P. h. forma homomalla is shorter with more robust terminal branches. The central stalk and branches are black or dark brown, and the polyps are cream-coloured, yellow, or pale brown. The calyces from which the polyps protrude are typically not projecting, but may be slightly raised above the surface of the coral. [2] [3] [4]

Distribution

P. homomalla is found growing on reefs in the Caribbean Sea, the Gulf of Mexico, the Bahamas, and Florida. It grows at depths down to about 55 m (180 ft) with P. h.forma homomalla being more abundant in shallow waters and P. h.forma kuekenthali occurring mostly at greater depths. [1] [3]

Ecology

P. homomalla contains a high level of the lipid prostaglandin A. This physiologically active substance is a million times more abundant in its tissues than in those of most other animals. The function of this large amount of prostaglandin in the coral is unknown. Its function in mammals is to act as a muscle relaxant. It is used to induce labour and it causes nausea and vomiting. P. homomalla contains 2 to 3% by weight of prostaglandin and was used as a source for the drug until methods for its synthesis became available in the 1970s. [5] Killifish, family Cyprinodontidae, and yellowhead wrasse ( Halichoeres garnoti ) vomit after being fed gelatine pellets containing prostaglandin. In feeding trials, the fish quickly learned to avoid these pellets while accepting control pellets. The prostaglandin produced by the coral seems to offer a chemical defence and act as a deterrent to predatory fishes. [6]

Related Research Articles

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.

Black coral Order of soft deep-water corals with chitin skeletons

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, surrounded by the polyps. Antipatharians are a cosmopolitan order, existing at nearly every 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.

Pillar coral Species of coral

Pillar coral is a hard coral found in the western Atlantic Ocean and the Caribbean Sea. It is the only species in the monotypic genus Dendrogyra. It is a digitate coral -that is, it resembles fingers or a cluster of cigars, growing up from the sea floor without any secondary branching. It is large and can grow on both flat and sloping surfaces at depths down to 20 m (65 ft). It is one of the few types of hard coral in which the polyps can commonly be seen feeding during the day.

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.

Flamingo tongue snail Species of gastropod

The flamingo tongue snail is a species of small but brightly colored sea snail, a marine gastropod mollusk in the family Ovulidae, the cowry allies.

<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>Iciligorgia schrammi</i> Species of coral

Iciligorgia schrammi, common names deepwater sea fan and black sea fan is a species of gorgonian sea fan in the family Anthothelidae. It is found in tropical parts of the Atlantic Ocean. This species was first described in 1870 by the French naturalist Édouard Placide Duchassaing de Fontbressin.

<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>Pseudodiploria strigosa</i> Species of coral

Pseudodiploria strigosa, the symmetrical brain coral, is a colonial species of stony coral in the family Mussidae. It occurs on reefs in shallow water in the West Atlantic Ocean and Caribbean Sea. It grows slowly and lives to a great age.

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

Gorgonia ventalina, the purple sea fan, is a species of sea fan, an octocoral in the family Gorgoniidae. It is found in the western Atlantic Ocean and the Caribbean Sea.

<i>Plexaurella nutans</i> Species of coral

Plexaurella nutans, the giant slit-pore sea rod, is a tall species of soft coral in the family Plexauridae. It is a relatively uncommon species and is found in shallow seas in the Caribbean region.

<i>Paragorgia arborea</i> Species of coral

Paragorgia arborea is a species of coral in the family Paragorgiidae, commonly known as the bubblegum coral because of its bulbous branch tips. It mainly grows in depths between 200 and 1,300 metres at temperatures between 3 and 8 °C. It is found widespread in the Northern Atlantic Ocean and Northern Pacific Ocean on seamounts and knolls, and was first described by the Swedish naturalist Carl Linnaeus in 1758. P. arborea is a foundation species, providing a habitat for other species in deep sea coral ecosystems.

<i>Paramuricea clavata</i> Species of coral

Paramuricea clavata, the violescent sea-whip, is a species of colonial soft coral in the family Plexauridae. It is found in shallow seas of the north-eastern Atlantic Ocean and the north-western Mediterranean Sea as well as Ionian Sea. This species was first described by the French naturalist Antoine Risso in 1826.

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

Eunicella singularis, the white gorgonian, is a species of colonial soft coral, a sea fan in the family Gorgoniidae. It is found in the western Mediterranean Sea, Adriatic Sea and Ionian Sea. It was first described in 1791 by the German naturalist Eugenius Johann Christoph Esper.

Pseudoplexaura porosa, commonly known as the porous sea rod or the porous false plexaura, is a species of gorgonian-type colonial octocoral in the family Plexauridae. It is native to the Caribbean Sea and the Gulf of Mexico.

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

Gorgonia mariae, commonly known as the wide-mesh sea fan, is a species of sea fan, a sessile colonial soft coral in the family Gorgoniidae. It occurs in the tropical western Atlantic Ocean and the Caribbean Sea at depths down to about 50 m (160 ft).

<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.

Endozoicomonas gorgoniicola is a Gram-negative and facultative anaerobic bacterium from the genus of Endozoicomonas. Individual cells are motile and rod-shaped. Bacteria in this genus are symbionts of coral. E. gorgoniicola live specifically with soft coral and were originally isolated from a species of Plexaura, an octocoral, off the coast of Bimini in the Bahamas. The presence of this bacterium in a coral microbiome is associated with coral health.

References

  1. 1 2 van Ofwegen, Leen (2010). "Plexaura homomalla (Esper, 1792)". WoRMS. World Register of Marine Species . Retrieved 2012-04-09.
  2. Bayer, 1961. Shallow water Octocorallia of the West Indian Region. Studies on the fauna of Curacao and other Caribbean Islands. 55.
  3. 1 2 Black Sea Rod (Plexaura homomalla) Marine Species Identification Portal. Retrieved 2012-04-10.
  4. Sheppard, Charles. Plexaura homomalla (Esper 1792) Coralpedia. Coventry, England: University of Warwick. Retrieved 2012-04-10.
  5. Valmsen, K.; Järving, I.; Boeglin, W. E.; Varvas, K.; Koljak, R.; Pehk, T.; Brash, A. R.; Samel, N. (2001). "The origin of 15R-prostaglandins in the Caribbean coral Plexaura homomalla: Molecular cloning and expression of a novel cyclooxygenase". PNAS. 98 (14): 7700–7705. Bibcode:2001PNAS...98.7700V. doi: 10.1073/pnas.131022398 . PMC   35405 . PMID   11427702.
  6. Gerhart, Donald J. (1984). "Prostaglandin A2, an agent of chemical defense in the Caribbean gorgonian Plexaura homomalla". Marine Ecology Progress Series. 19: 181–187. Bibcode:1984MEPS...19..181G. doi: 10.3354/meps019181 .