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Luidia Magellanica
''Luidia magellanica'' is a species of starfish in the family Luidiidae. It is found in the southeastern Pacific Ocean on the coast of South America. Distribution and habitat ''Luidia magellanica'' occurs subtidally in the southeastern Pacific Ocean, on the coasts of Peru and Chile. Its typical habitat is on rock bottoms with encrusting red algae, ''Lithophyllum'', or soft sediments composed of coarse sand and shell fragments. Ecology ''Luidia magellanica'' is a large and aggressive specialist predator of other echinoderms. Its diet includes brittle stars such as '' Ophiactis'', sea urchins such as '' Tetrapygus niger'' and starfish such as '' Patiria''. In the subtidal zone of temperate Chile it feeds on eight different species of echinoderm, and with '' Meyenaster gelatinosus'' is the dominant predator. Many of the starfish in this zone have missing or regenerating arms, and this is likely to be as a result of a near-lethal encounter with either ''L. magellanica'' or ''M. ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfish
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannibalism
Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, both in ancient and in recent times. The rate of cannibalism increases in nutritionally poor environments as individuals turn to members of their own species as an additional food source.Elgar, M.A. & Crespi, B.J. (1992) ''Cannibalism: ecology and evolution among diverse taxa'', Oxford University Press, Oxford ngland New York. Cannibalism regulates population numbers, whereby resources such as food, shelter and territory become more readily available with the decrease of potential competition. Although it may benefit the individual, it has been shown that the presence of cannibalism decreases the expected survival rate of the whole population and increases the risk of consuming a relative. Other negative effects may include the increased r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luidia
''Luidia'' is a genus of starfish in the Family (biology), family Luidiidae in which it is the only genus. Species of the family have a cosmopolitan distribution. Characteristics Members of the genus are characterised by having long arms with pointed tips fringed with spines. Their upper surfaces are covered with Paxilla (ossicle), paxillae, pillar-like spines with flattened summits covered with minute spinules. The upper marginal plates are replaced by paxillae, but the lower marginal plates are large and covered with paxillae. The tube feet do not have suckers, but have two swollen regions. A mouth, oesophagus, and cardiac stomach are seen, but no pyloric stomach or anus is present. The gonads are underneath the sides of each arm. The early larval stages of starfish are known as bipinnarial larvae, and members of this genus do not continue their development after this stage into a brachiolar stage before undergoing metamorphosis. However, they are capable of larval cloning, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapygus Niger
''Tetrapygus'' is a genus of sea urchins in the family Arbaciidae. It is a monotypic genus and the only species is ''Tetrapygus niger'' which was first described by the Chilean naturalist Juan Ignacio Molina in 1782. It is found in the southeastern Pacific Ocean on the coasts of South America. Description The oral (under) surface of the test is flattened while the aboral (upper) surface is shallowly domed. There is a small apical disc and the ambulacral areas are straight. There are up to five large primary tubercles in rows in the inter-ambulacral areas, interspersed with smaller secondary tubercles. The mouth is surrounded by a sunken subpentagonal peristome which is half as wide as the test. The primary spines are moderately long while the secondary spines are short. The colour of this sea urchin is purplish-black. Distribution ''T. niger'' is found in the southeastern Pacific Ocean on the coasts of Peru and Chile, its range extending from northern Peru to the Strait of Magel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date Line and 120°W), including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. El Niño phases are known to last close to four years; however, records demonstrate that the cycles have lasted between two and seven years. During the development of El Niño, rainfall develops between September–November. The cool phase of ENSO is es, La Niña, translation=The Girl, with SSTs in the eastern Pacific below average, and air pressure high in the eastern Pacific and low in the western Pacific. The ENSO cycle, including bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stichaster Striatus
''Stichaster striatus'', the common light striated star, is a species of starfish in the family Stichasteridae, found in the southeastern Pacific Ocean. It was first described by the German zoologists Johannes Peter Müller and Franz Hermann Troschel in 1840. Distribution and habitat ''Stichaster striatus'' is native to the southeastern Pacific Ocean, along the coast of South America. It occurs on rocky and sandy seabeds and among kelp in intertidal areas, with a maximum depth of . Ecology This starfish is gregarious and a predator. Although it has been recorded in Chile as feeding on twenty-eight different species of invertebrate, the majority of these were sessile organisms. It was not found to engage in cannibalism of its own species or to feed on other species of starfish. Many individuals were found to have missing or regenerating arms. This is likely the result of attacks by the dominant predatory starfish in the region '' Meyenaster gelatinosus'' and ''Luidia magell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patiria Chilensis
''Patiria chilensis'' is a species of starfish in the family Asterinidae. It is found in the southeastern Pacific Ocean along the coasts of South America. It is a broadly pentagonal, cushion-like starfish with five short arms. Ecology ''P. chilensis'' occurs in the rocky intertidal zone in temperate seas off the coast of Chile. It is mainly present in the lower algal zone, dominated by the kelps ''Lessonia nigrescens'' and ''Durvillaea antarctica'' and various encrusting coralline algae. Echinoids occurring in this zone include ''Loxechinus albus'' and ''Tetrapygus niger'', and starfish include ''Stichaster striatus'', '' Meyenaster gelatinosus'' and the dominant ''Heliaster helianthus''. These starfish are the dominant carnivores in this zone and seem to play an important role in maintaining the community structure. Besides being a predator of sessile organisms, ''P. chilensis'' is an opportunistic feeder, scavenging for dead animal matter and detritus In biology, detritus ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autotomy
Autotomy (from the Greek language, Greek ''auto-'', "self-" and ''tome'', "severing", wikt:αὐτοτομία, αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-preservation, self-defense mechanism to elude a predation, predator's grasp or to distract the predator and thereby allow escape. Some animals have the ability to regeneration (biology), regenerate the lost body part later. Autotomy has multiple evolutionary origins and is thought to have evolved at least nine times independently in animalia. The term was coined in 1883 by Léon Fredericq, Leon Fredericq. Vertebrates Reptiles and amphibians Some lizards, salamanders and tuatara when caught by the tail will shed part of it in attempting to escape. In many species the detached tail will continue to wriggle, creating a deceptive sense of continued struggle, and distracting the predator's attention from the fleeing prey animal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meyenaster
''Meyenaster'' is a genus of starfish in the family Asteriidae. It is a monotypic genus and the only species is ''Meyenaster gelatinosus'' which was first described by the Prussian botanist and zoologist Franz Julius Ferdinand Meyen in 1834. It is found in the southeastern Pacific Ocean on the coasts of South America. Description ''M. gelatinosus'' is a white starfish with six arms and a mean radius ranging from . Distribution and habitat ''M. gelatinosus'' is native to the southeastern Pacific Ocean where it is found on the coasts of Chile. It is abundant in kelp forests in the subtidal zone as well as being found on sand and gravel bottoms, and among seagrasses. It is usually found in areas with strong surge away from quiet locations. Ecology In the kelp forests, ''M. gelatinosus'' is one of the dominant predators along with the starfish ''Stichaster striatus'', ''Luidia magellanica'' and ''Heliaster helianthus'', the fish ''Pinguipes chilensis'', '' Semicossyphus darwini'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luidiidae
''Luidia'' is a genus of starfish in the family Luidiidae in which it is the only genus. Species of the family have a cosmopolitan distribution. Characteristics Members of the genus are characterised by having long arms with pointed tips fringed with spines. Their upper surfaces are covered with paxillae, pillar-like spines with flattened summits covered with minute spinules. The upper marginal plates are replaced by paxillae, but the lower marginal plates are large and covered with paxillae. The tube feet do not have suckers, but have two swollen regions. A mouth, oesophagus, and cardiac stomach are seen, but no pyloric stomach or anus is present. The gonads are underneath the sides of each arm. The early larval stages of starfish are known as bipinnarial larvae, and members of this genus do not continue their development after this stage into a brachiolar stage before undergoing metamorphosis. However, they are capable of larval cloning, with asexual reproduction taking pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patiria
''Patiria'' is a genus of starfish in the family Asterinidae The Asterinidae are a large family of sea stars in the order Valvatida. Description and characteristics These are generally small sea stars, flattened dorsally and bearing very short arms, often giving a pentagonal shape in the body ;example: ... from the Pacific Ocean. Species ''Patiria'' contains the following species: References Asterinidae Asteroidea genera Taxa named by John Edward Gray {{Asteroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapygus
''Tetrapygus'' is a genus of sea urchins in the family Arbaciidae. It is a monotypic genus and the only species is ''Tetrapygus niger'' which was first described by the Chilean naturalist Juan Ignacio Molina in 1782. It is found in the southeastern Pacific Ocean on the coasts of South America. Description The oral (under) surface of the test is flattened while the aboral (upper) surface is shallowly domed. There is a small apical disc and the ambulacral areas are straight. There are up to five large primary tubercles in rows in the inter-ambulacral areas, interspersed with smaller secondary tubercles. The mouth is surrounded by a sunken subpentagonal peristome which is half as wide as the test. The primary spines are moderately long while the secondary spines are short. The colour of this sea urchin is purplish-black. Distribution ''T. niger'' is found in the southeastern Pacific Ocean on the coasts of Peru and Chile, its range extending from northern Peru to the Strait of Mage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
