Fire coral
Encyclopedia
Fire corals are colonial marine organisms that look rather like real coral
. However they are technically not corals; they are actually more closely related to jellyfish
and other stinging anemones
. They are members of the phylum Cnidaria
, class Hydrozoa
, order Capitata
, family Milleporidae.
stings). In addition, fire corals have a sharp, calcified external skeleton that can scrape the skin.
Fire coral has several common growth forms; these include branching, plate and encrusting. Branching adopts a calcerious structure which branches off, to rounded finger-like tips. Plate adopts a shape similar to that of the smaller non-sheet lettuce corals; therefore erect, thin sheets, which group together to form a colony. The latter; "encrusting", is where the fire coral forms on the calcerious structure of other coral or gorgonian structures.
The gonophore
s in the family Milleporidae arise from the coenosarc (i.e. the hollow living tubes of the upright branching individuals of a colony) within chambers embedded entirely in the coenosteum (i.e. the calcareous mass forming the skeleton of a compound coral).
s in the Indian, Pacific and Atlantic Oceans. They form extensive outcrops on projecting parts of the reef where the tidal currents are strong. They are also abundant on upper reef slopes and in lagoons, and occur down to depths of 40 metres.
s of fire corals are near microscopic size and are mostly embedded in the skeleton and connected by a network of minute canals. All that is visible on the smooth surface are pores of two sizes: gastropores and dactylopores. In fact, Millepora means ‘many pores’. Dactylopores have long fine hairs that protrude from the skeleton. The hairs possess clusters of stinging cells and capture prey, which is then engulfed by gastrozooids, or feeding polyps, situated within the gastropores. As well as capturing prey, fire corals gain nutrients via their special symbiotic
relationship with algae known as zooxanthella
e. The zooxanthellae live inside the tissues of the coral, and provide the coral with food, which they produce through photosynthesis
, and therefore require sunlight. In return, the coral provides the algae with protection and access to sunlight.
Reproduction in fire corals is more complex than in other reef-building corals. The polyps reproduce asexually
, producing jellyfish-like medusa
e, which are released into the water from special cup-like structures known as ampullae. The medusae contain the reproductive organs that release eggs and sperm into the water. Fertilised eggs develop into free-swimming larvae that will eventually settle on the substrate and form new colonies. Fire corals can also reproduce asexually by fragmentation.
Most fire coral species have brittle skeletons that can easily be broken, for example, during storms, or by divers. Divers can easily break the branches of fire corals when diving for leisure, or when collecting fish for the aquarium trade. For instance, the yellowtail damselfish (Chrysiptera parasema
) tends to dwell close to the branching fire coral colonies, and retreats into its branches when threatened. In Brazil
, fire coral colonies are extensively damaged when harvesting the yellowtail damselfish, as the corals are often deliberately smashed and fishes hiding amongst the branches are ‘shaken out’ into plastic bags.
Fire corals are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES).
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
. However they are technically not corals; they are actually more closely related to jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
and other stinging anemones
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
. They are members of the phylum Cnidaria
Cnidaria
Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...
, class Hydrozoa
Hydrozoa
Hydrozoa are a taxonomic class of very small, predatory animals which can be solitary or colonial and which mostly live in saltwater. A few genera within this class live in freshwater...
, order Capitata
Capitata
The word Capitata comes from the Latin capitatus, meaning "having a head". It may refer to:* Capitata , a suborder of Anthomedusae* Capitata Group, a cultivar group of the species Brassica oleracea, containing the cabbages...
, family Milleporidae.
Distinguishing characteristics
Fire corals have a bright yellow-green and brown skeletal covering and are widely distributed in tropical and subtropical waters. They appear in small brush-like growths on rocks and coral. Divers often mistake fire coral for seaweed, and accidental contact is common. Upon contact, an intense pain can be felt that can last from two days to two weeks. The very small nematocysts on fire corals contain tentacles that protrude from numerous surface pores (similar to jellyfishJellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
stings). In addition, fire corals have a sharp, calcified external skeleton that can scrape the skin.
Fire coral has several common growth forms; these include branching, plate and encrusting. Branching adopts a calcerious structure which branches off, to rounded finger-like tips. Plate adopts a shape similar to that of the smaller non-sheet lettuce corals; therefore erect, thin sheets, which group together to form a colony. The latter; "encrusting", is where the fire coral forms on the calcerious structure of other coral or gorgonian structures.
The gonophore
Gonophore
A gonophore is a reproductive organ in Hydrozoa that produces gametes. It is a sporosac, a medusa or any intermediate stage.The name is derived from the Greek words gone and phoreus ....
s in the family Milleporidae arise from the coenosarc (i.e. the hollow living tubes of the upright branching individuals of a colony) within chambers embedded entirely in the coenosteum (i.e. the calcareous mass forming the skeleton of a compound coral).
Distribution and habitat
Fire corals are found on reefReef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s in the Indian, Pacific and Atlantic Oceans. They form extensive outcrops on projecting parts of the reef where the tidal currents are strong. They are also abundant on upper reef slopes and in lagoons, and occur down to depths of 40 metres.
Biology
The polypPolyp
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
s of fire corals are near microscopic size and are mostly embedded in the skeleton and connected by a network of minute canals. All that is visible on the smooth surface are pores of two sizes: gastropores and dactylopores. In fact, Millepora means ‘many pores’. Dactylopores have long fine hairs that protrude from the skeleton. The hairs possess clusters of stinging cells and capture prey, which is then engulfed by gastrozooids, or feeding polyps, situated within the gastropores. As well as capturing prey, fire corals gain nutrients via their special symbiotic
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
relationship with algae known as zooxanthella
Zooxanthella
Zooxanthellae are flagellate protozoa that are golden-brown intracellular endosymbionts of various marine animals and protozoa, especially anthozoans such as the scleractinian corals and the tropical sea anemone, Aiptasia....
e. The zooxanthellae live inside the tissues of the coral, and provide the coral with food, which they produce through photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
, and therefore require sunlight. In return, the coral provides the algae with protection and access to sunlight.
Reproduction in fire corals is more complex than in other reef-building corals. The polyps reproduce asexually
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
, producing jellyfish-like medusa
Medusa
In Greek mythology Medusa , " guardian, protectress") was a Gorgon, a chthonic monster, and a daughter of Phorcys and Ceto. The author Hyginus, interposes a generation and gives Medusa another chthonic pair as parents. Gazing directly upon her would turn onlookers to stone...
e, which are released into the water from special cup-like structures known as ampullae. The medusae contain the reproductive organs that release eggs and sperm into the water. Fertilised eggs develop into free-swimming larvae that will eventually settle on the substrate and form new colonies. Fire corals can also reproduce asexually by fragmentation.
Threats and conservation
Fire corals face the many threats that are impacting coral reefs globally which include poor land management practices that are releasing more sediment, nutrients and pollutants into the oceans and stressing the fragile reef ecosystem. Overfishing has ‘knock-on’ effects that result in the increase of macro-algae that can out-compete and smother corals, and fishing using destructive methods physically devastates the reef. A further potential threat is the increase of coral bleaching events, as a result of global climate change.Most fire coral species have brittle skeletons that can easily be broken, for example, during storms, or by divers. Divers can easily break the branches of fire corals when diving for leisure, or when collecting fish for the aquarium trade. For instance, the yellowtail damselfish (Chrysiptera parasema
Chrysiptera parasema
Chrysiptera parasema, also known as Yellowtail Damselfish or Goldtail demoiselle is a popular saltwater aquarium fish from the Indo-Pacific.-Appearance:A small marine fish that reaches three inches in length. It is blue with a yellow tail....
) tends to dwell close to the branching fire coral colonies, and retreats into its branches when threatened. In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, fire coral colonies are extensively damaged when harvesting the yellowtail damselfish, as the corals are often deliberately smashed and fishes hiding amongst the branches are ‘shaken out’ into plastic bags.
Fire corals are listed on Appendix II of the Convention on International Trade in Endangered Species (CITES).
Species
Thirteen species of Millepora are currently recognised:- Millepora alcicornis Linnaeus, 1758
- Millepora boschmai de Weerdt & Glynn, 1991
- Millepora braziliensis Verrill, 1868
- Millepora complanata Lamarck, 1816
- Millepora dichotoma (Forsskål, 1775)
- Millepora exaesa (Forsskål, 1775)
- Millepora foveolata Crossland, 1952
- Millepora intricata Milne-Edwards & Haime, 1860
- Millepora laboreli Amaral, 2008
- Millepora latifolia Boschma, 1948
- Millepora platyphylla Hemprich & Ehrenberg, 1834
- Millepora squarrosa Lamarck, 1816
- Millepora tenera Boschma, 1948
External links
- "Fire Coral Cuts Treatment" at WebMDWebMDWebMD is an American corporation which provides health information services. It was founded in 1996 by Jim Clark and Pavan Nigam as Healthscape, later Healtheon, and then acquired WebMD in 1999 to form Healtheon/WebMD...
- http://www.emedicinehealth.com/wilderness_fire_coral_cuts/article_em.htm