| Gorgonia flabellum | |
|---|---|
 | |
| Venus sea fan showing lateral branchlets | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Octocorallia |
| Order: | Alcyonacea |
| Family: | Gorgoniidae |
| Genus: | Gorgonia |
| Species: | G. flabellum |
| Binomial name | |
| Gorgonia flabellum | |
Gorgonia flabellum, also known as the Venus fan, Venus sea fan, West Indian sea fan, purple gorgonian seafan, and common sea fan, is a species of sea fan, a sessile colonial soft coral. [2]
The Venus sea fan is a delicate-looking colonial soft coral in the form of a fan composed of a lattice of branches in a single plane. The coral grows from a small base, forming several main branches with side branches and a network of small branchlets. The Venus sea fan is similar in appearance to Gorgonia ventalina , but has a slightly more untidy shape and short, stubby side growths coming out of the main plane. [3] In G. flabellum, the branches are flattened at right angles to the plane of the fan, while in G. ventalina, the branches are either round or flattened parallel to the plane of the fan. The wide-mesh sea fan ( Gorgonia mariae ) is also similar in appearance, but at only 30 centimetres (11.8 in), is smaller, and many of the branchlets do not interconnect. [4] The Venus sea fan is white, yellowish, or pale lavender. The fan is often found oriented perpendicular to the incoming waves and can grow to a height of 1.5 m (4 ft 11 in). [3] [5]
The Venus sea fan is very common in the Bahamas, and in this location is easily distinguishable from G. ventalina. In other parts of its range, Florida and the Lesser Antilles, however, the two species are more easily confused.[ why? ] It is a shallow-water species seldom exceeding a depth of 10 m (33 ft) and favours locations with strong wave action. [3]
The skeleton of the Venus sea fan is composed of calcite and a collagen-like substance. Embedded in this are the coral polyps, each of which is a filter feeder and extends its eight tentacles to catch plankton drifting past with the current. [3] The tissues contain symbiotic dinoflagellate algae Symbiodinium spp. which are photosynthetic and use sunlight to create organic carbon compounds which are then available to the host coral. [3]
The Venus sea fan is threatened by a variety of pathogens, including cyanobacteria and the fungal pathogen Aspergillus. [6] [7] Cyanobacterial overgrowth, particularly by filamentous Oscillatoriales, causes tissue necrosis and disrupts the sea fan's structure. [6] Additionally, Aspergillus infections have been linked to large-scale tissue loss, especially in larger colonies and deeper waters. [7]
White band disease is a coral disease that affects acroporid corals and is distinguishable by the white band of exposed coral skeleton that it forms. The disease completely destroys the coral tissue of Caribbean acroporid corals, specifically elkhorn coral and staghorn coral. The disease exhibits a pronounced division between the remaining coral tissue and the exposed coral skeleton. These symptoms are similar to white plague, except that white band disease is only found on acroporid corals, and white plague has not been found on any acroporid corals. It is part of a class of similar disease known as "white syndromes", many of which may be linked to species of Vibrio bacteria. While the pathogen for this disease has not been identified, Vibrio carchariae may be one of its factors. The degradation of coral tissue usually begins at the base of the coral, working its way up to the branch tips, but it can begin in the middle of a branch.
Black band disease is a coral disease in which corals develop a black band. It is characterized by complete tissue degradation due to a pathogenic microbial consortium. The mat is present between apparently healthy coral tissue and freshly exposed coral skeleton.
Gorgonia is a genus of soft corals, sea fans in the family Gorgoniidae.
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.
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.
White pox disease, first noted in 1996 on coral reefs near the Florida Keys, is a coral disease affecting Elkhorn coral throughout the Caribbean. It causes irregular white patches or blotches on the coral that result from the loss of coral tissue. These patches distinguish white pox disease from white band disease which produces a distinctive white band where the coral skeleton has been denuded. The blotches caused by this disease are also clearly differentiated from coral bleaching and scars caused by coral-eating snails. It is very contagious, spreading to nearby coral.
Yellow-band disease is a coral disease that attacks colonies of coral at a time when coral is already under stress from pollution, overfishing, and climate change. It is characterized by large blotches or patches of bleached, yellowed tissue on Caribbean scleractinian corals.
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.
Simnia spelta is a species of sea snail, a marine gastropod mollusc in the family Ovulidae, the ovulids, which are cowrie allies sometimes called "false cowries". It was first described in 1758 by the Swedish naturalist Carl Linnaeus.
In 1758, in the 10th edition of Systema Naturae, the Swedish scientist and taxonomist Carl Linnaeus described the class "Vermes" as:
Animals of slow motion, soft substance, able to increase their bulk and restore parts which have been destroyed, extremely tenacious of life, and the inhabitants of moist places. Many of them are without a distinct head, and most of them without feet. They are principally distinguished by their tentacles. By the Ancients they were not improperly called imperfect animals, as being destitute of ears, nose, head, eyes and legs; and are therefore totally distinct from Insects.
Amphimedon compressa, the erect rope sponge, red tree sponge, red tubular sponge, or red sponge is a demosponge found in southern Florida, the Caribbean Sea, and the Bahamas. It can be deep red, orange, brown, or black.
Gorgoniidae is a family of soft corals, a member of the subclass Octocorallia in the phylum Cnidaria. Nearly all the genera and species are native to the east and west coasts of America.
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 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.
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.
The branch coral is a species of acroporid coral found in the southwest and northern Indian Ocean, the central Indo-Pacific, Australia, Southeast Asia, Japan and the East China Sea, Cook Islands and the oceanic west Pacific Ocean. It can be found in shallow reefs on the reef tops, walls and slopes to depths of 30 m.
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.
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).
Manicina areolata, commonly known as rose coral, is a colonial species of stony coral. It occurs in shallow water in the West Atlantic Ocean and Caribbean Sea, sometimes as small solid heads and sometimes as unattached cone-shaped forms.
Coral diseases are transmissible pathogens that cause the degradation of coral colonies. Coral cover in reef ecosystems has decreased significantly for a diverse set of reasons, ranging from variable environmental conditions to mechanical breakdowns from storms. In recent years, diseases that infect and kill coral have shown to be a threat to the health of coral reefs. Since the first coral disease was reported in 1965, many different kinds of diseases have popped up in mostly Caribbean waters. These diseases are diverse, including pathogens of bacteria, fungi, viruses, and protozoans. Coral diseases have widespread implications, impacting entire ecosystems and communities of organisms. Researchers are working to understand these diseases, and how potential treatments could stop these pathogens from causing the widespread death of corals in a way that permanently impacts the community structure of reefs.
