| Gorgonia ventalina | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Octocorallia |
| Order: | Alcyonacea |
| Family: | Gorgoniidae |
| Genus: | Gorgonia |
| Species: | G. ventalina |
| Binomial name | |
| Gorgonia ventalina | |
Gorgonia ventalina, the common sea fan and 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.
G. ventalina is a fan-shaped colonial coral with several main branches and a latticework of linking smaller branches. The skeleton is composed of calcite and gorgonin, a collagen-like compound. The calyces in which the polyps are embedded are in two rows along the branches. Many of the smaller branches are compressed in the plane of the fan, which distinguishes this species from the Venus sea fan ( Gorgonia flabellum ). It often has small accessory fans growing out sideways from the main fan. It grows to 1.5 m (5 ft) tall and is variable in colour, being whitish, yellow, or pale purple. The main branches are often purple and the fan is orientated at right angles to the current. [3] [4]
The purple sea fan is found in the western Atlantic and Caribbean, with a range extending from Bermuda and Florida and the Gulf of Mexico to Curaçao. It grows near the shore in shallow water in areas with strong wave action and on deeper outer reefs with strong currents down to a depth of about 15 m (49 ft). [3]
G. ventalina is a filter feeder. Each polyp extends its eight tentacles to catch plankton drifting past on the current. Its tissues contain symbiotic dinoflagellate Symbiodinium spp., which are photosynthetic and use sunlight to create organic carbon compounds which are then available to the host coral. [5]
The skeleton of G. ventalina contains hard structures known as sclerites which are unpalatable to predators. It also contains certain secondary metabolites in its tissues which are distasteful. The nudibranch Tritonia hamnerorum seems undeterred by these defences and is often found associated with the coral. While feeding on the coral, it concentrates the metabolites in its tissues which render it unpleasant to potential predators. [5] This is because T.hamnerorum sequesters the chemical compound julieannfuran from G.ventalina to use as a chemical deterrent to predators. [6]
This coral is sometimes attacked by the fungus Aspergillus sydowii which causes aspergillosis. This results in damaged patches, galls, purpling of the tissues, and even coral death. Several epizootics have occurred in the Caribbean on corals growing in stressful conditions such as in low-salinity water in estuaries which seem especially susceptible. [5] A parasite of the class Labyrinthulomycetes in the family Thraustochytriidae has been found to have similar effects of damaged purple patches on the fan called multifocal purple spots. [7]
A study done in the U.S. Virgin Islands has shown that G. ventalina has a high ecological resilience with populations maintaining their densities after two hurricanes in 2017. [8]
Nudibranchs are a group of soft-bodied marine gastropod molluscs that shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", and "sea rabbit". Currently, about 3,000 valid species of nudibranchs are known.
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.
Alcyonacea are a species 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" (Octocorallia) that are quite different from "true" corals (Scleractinia). 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.
The flamingo tongue snail is a species of small but brightly colored sea snail, a marine gastropod mollusk in the family Ovulidae, the ovulids, cowry allies or false cowries.
The diamondback tritonia is a species of nudibranch, a marine gastropod mollusk in the family Tritoniidae. It is an opportunistic predator of other marine invertebrates.
The soft coral nudibranch, Tritonia sp. 1, as designated by Gosliner, 1987, is a species of small sea slug, a dendronotid nudibranch. It is a marine gastropod mollusc in the family Tritoniidae. As of November 2009, it was undescribed by science.
Tritonicula hamnerorum is a species of dendronotid nudibranch. It is a marine gastropod mollusc in the family Tritoniidae. A number of Caribbean species of Tritonia were moved to a new genus Tritonicula in 2020 as a result of an integrative taxonomic study of the family Tritoniidae.
Leptogorgia virgulata, commonly known as the sea whip or colorful sea whip, is a species of soft coral in the family Gorgoniidae.
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.
Gorgonia flabellum, also known as the Venus fan, Venus sea fan, West Indian sea fan, and purple gorgonian seafan, is a species of sea fan, a sessile colonial soft 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.
Aspergillus sydowii is a pathogenic fungus that causes several diseases in humans. It has been implicated in the death of sea fan corals in the Caribbean Sea.
Lobophora variegata is a species of small thalloid brown alga which grows intertidally or in shallow water in tropical and warm temperate seas. It has three basic forms, being sometimes ruffled, sometimes reclining and sometimes encrusting, and each form is typically found in a different habitat. This seaweed occurs worldwide. It is the type species of the genus Lobophora, the type locality being the Antilles in the West Indies.
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.
Antillogorgia bipinnata, the bipinnate sea plume, is a species of colonial soft coral, a sea fan in the family Gorgoniidae. It is found in the Caribbean Sea. It was first described as Pseudopterogorgia bipinnata in 1864 by the American zoologist Addison Emery Verrill. Williams and Chen (2012), transferred all the Atlantic species of Pseudopterogorgia to Antillogorgia.
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.
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.
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).
Tritoniella is a genus of sea slugs, specifically dendronotid nudibranchs. It is a marine gastropod mollusc in the family Tritoniidae.The genus was described in 1907 by the British diplomat and malacologist Charles Eliot.
Conopea galeata is a species of colonial barnacle in the family Archaeobalanidae. It lives exclusively on gorgonians in the western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
