| Galaxea astreata | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Hexacorallia |
| Order: | Scleractinia |
| Family: | Euphylliidae |
| Genus: | Galaxea |
| Species: | G. astreata |
| Binomial name | |
| Galaxea astreata (Lamarck, 1816) | |
| Synonyms | |
List
| |
(Lamark, 1816)
Galaxea astreata is a common and cosmopolitan large polyp scleractinian coral, (stony, hard coral) in the family Euphylliidae . It has a sub-massive morphology. It is found in the Indo-Pacific [2] and is the most abundant coral species in Xuwen Coral Reef National Nature Reserve. G. astreata is acclimatized to water temperatures ranging from about 27 ± 0.5 °C. [3] It is generally a shallow-water coral and is commonly seen at a depth of around 15 meters. It can range from a depth of 1 meter to 30 meters. [4] It generally prefers clear, salt waters over turbid brackish waters. [5]
Galaxea astreata has a very distinctive skeleton structure, which is made of calcium carbonate (CaCO3). Corallites, the skeletal cup formed by individual polyps, are very plate-like. They are about 3-4.5 in diameter. They are also well spaced. [6] The coral can has a symbiotic relationship with zooxanthellae living inside of the coral. [5] Colonies of G. astreata are either sub-massive, columnar, or encrusting, meaning they can either be irregularly shaped, growing upward like columns, or impinging on a hard substrate. Colonies can grow to be over two meters long. The polyps are usually found to be pink, grey, green, or brown in color. [6]
Galaxea astreata eat zooplankton and coral larvae that float by. Corals tend to feed at night since planktivorous fishes are sleeping. G. astreata expands its polyps to feed during the day, and contracts them at night. It is an effective predator, and like other massive growth forms, G. astreata will be an even more efficient when the larvae starts sinking in the water column so that it is easier for the coral to catch. [7]
Galaxea astreata is a broadcast spawner, as gametes are released into the water for external fertilization. After the gamete is fertilized, the planulae, or the larval form of the coral, develops inside the plankton. [5] G. astreata can either be a hermaphrodite, having both male and female gametes, or a gonochore, having gametes of only one sex. [5]
The coral coverage rate in Xuwen rapidly decreased due to human activity and other environmental factors causing a decline in the G. astreata. [8] Some detrimental human activities include overuse of fisheries and extraction, eutrophication and siltation, and pollution. [9] Though G. astreata is more resistant to environmental changes than other coral species (i.e. Accropora spp.), [10] it had a 100% mortality rate after the El Niño phenomenon of 1997-1998, starting with slow death of tissue fragments in the first 4 months after the disturbance. [11] However, G. astreata was not the only coral affected, as this 1998 coral bleaching event reduced the richness of all coral species off the coast of Sesoko Island, Japan by 61% and reduced coral cover by 85%. Temperatures rose 2.8 °C above average from this one event alone. [12] Coral bleaching events cause a loss of the symbiotic algae (zooxanthellae) and/or a loss of pigment (color mostly derived from zooxanthellae). It is a global phenomenon that is most likely linked to global climate change and rising ocean temperatures, as well as ocean acidification. [12]
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard 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.
Montipora is a genus of Scleractinian corals in the phylum Cnidaria. Members of the genus Montipora may exhibit many different growth morphologies. With eighty five known species, Montipora is the second most species rich coral genus after Acropora.
The four-spotted butterflyfish or fourspot butterflyfish is a species of butterflyfish found in the Pacific Ocean from the Ryukyus, Ogasawara (Bonin) Islands and Taiwan to the Hawaiian, Marquesan, and Pitcairn islands, south to the Samoan and Austral Islands and the Marianas and Marshall Islands in Micronesia.
Millepora dichotoma, the net fire coral, is a species of hydrozoan, consisting of a colony of polyps with a calcareous skeleton.
Galaxea is a genus of colonial stony corals in the family Euphylliidae. Common names include crystal, galaxy, starburst and tooth coral. They are abundant on reefs in the Indo-Pacific region and the Red Sea. They are found in water less than 20 metres (66 ft) deep and favour turbid sites. They are sometimes kept in reef aquaria.
Galaxea fascicularis is a species of colonial stony coral in the family Euphylliidae, commonly known as octopus coral, fluorescence grass coral, galaxy coral among various vernacular names.
Porites lobata, known by the common name lobe coral, is a species of stony coral in the family Poritidae. It is found growing on coral reefs in tropical parts of the Indian and Pacific Oceans.
Scolymia, commonly called scoly coral, is a genus of large-polyp stony corals (Scleractinia). These animals are believed date back to the Miocene with three extant species present in the eastern Atlantic Ocean.
Millepora platyphylla is a species of fire coral, a type of hydrocoral, in the family Milleporidae. It is also known by the common names blade fire coral and plate fire coral. It forms a calcium carbonate skeleton and has toxic, defensive polyps that sting. It obtains nutrients by consuming plankton and via symbiosis with photosynthetic algae. The species is found from the Red Sea and East Africa to northern Australia and French Polynesia. It plays an important role in reef-building in the Indo-Pacific region. Depending on its environment, it can have a variety of different forms and structures.
Euphyllia ancora is a species of hard coral in the family Euphylliidae. It is known by several common names, including anchor coral and hammer coral, or less frequently as sausage coral, ridge coral, or bubble honeycomb coral.
Pocillopora damicornis, commonly known as the cauliflower coral or lace coral, is a species of stony coral in the family Pocilloporidae. It is native to tropical and subtropical parts of the Indian and Pacific Oceans.
Astrangia poculata, the northern star coral or northern cup coral, is a species of non-reefbuilding stony coral in the family Rhizangiidae. It is native to shallow water in the western Atlantic Ocean and the Caribbean Sea. It is also found on the western coast of Africa. The International Union for Conservation of Nature lists this coral as being of "least concern". Astrangia poculata is an emerging model organism for corals because it harbors a facultative photosymbiosis, is a calcifying coral, and has a large geographic range. Research on this emerging model system is showcased annually by the Astrangia Research Working Group, collaboratively hosted by Roger Williams University, Boston University, and Southern Connecticut State University
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.
Coelastrea aspera is a species of stony coral in the family Merulinidae. It is a colonial species native to the Indo-Pacific region where it occurs in shallow water. It was first described by the American zoologist Addison Emery Verrill in 1866 as Goniastrea aspera but it has since been determined that it should be in a different genus and its scientific name has been changed to Coelastrea aspera. This is a common species throughout much of its wide range and the International Union for Conservation of Nature has rated its conservation status as being of "least concern".
Porites cylindrica, commonly known as hump coral, is a stony coral belonging to the subclass Hexacorallia in the class Anthozoa. Hexacorallia differ from other subclasses in that they have 6 or fewer axes of symmetry. Members of this class possess colonial polyps which can be reef-building, secreting a calcium carbonate skeleton. They are dominant in both inshore reefs and midshelf reefs.
A corallivore is an animal that feeds on coral. Corallivores are an important group of reef organism because they can influence coral abundance, distribution, and community structure. Corallivores feed on coral using a variety of unique adaptations and strategies. Animals known to be corallivores include certain mollusks, annelids, fish, crustaceans, flatworms and echinoderms. The first recorded evidence of corallivory was presented by Charles Darwin in 1842 during his voyage on HMS Beagle in which he found coral in the stomach of two Scarus parrotfish.
Oxypora glabra is a species of large polyp stony coral in the family Lobophylliidae. It is a colonial coral with thin encrusting laminae. It is native to the central Indo-Pacific.
Heterocyathus is a genus of coral of the family Caryophylliidae.
Heteropsammia is a genus of apozooxanthellate corals that belong to the family Dendrophylliidae.
