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Comatulida
Comatulida is an order of crinoids. Members of this order are known as feather stars and mostly do not have a stalk as adults. The oral surface with the mouth is facing upwards and is surrounded by five, often divided rays with feathery pinnules. Comatulids live on the seabed and on reefs in tropical and temperate waters. Taxonomy Bourgueticrinida, the sea lilies, has traditionally been viewed as an order of Articulata and a sister taxon to Comatulida. A study published in 2011 suggested that it should be renamed Bourgueticrinina and viewed as a suborder of Comatulida. Characteristics Like other echinoderms, comatulids have pentamerous symmetry (five sided) as adults though the larvae have bilateral symmetry. Late in their development, the larvae are attached to the seabed by a stalk, but this is broken at metamorphosis and the juvenile crinoid is free living. The body has an endoskeleton made from a number of articulated calcareous plates known as ossicles covered by a thin e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crinoidea
Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as . Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near the mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Articulata (Crinoidea)
Articulata are a subclass or superorder within the class Crinoidea, including the only living crinoid species. They are commonly known as sea lilies (stalked crinoids) or feather stars (unstalked crinoids). The Articulata are differentiated from the extinct subclasses by their lack of an anal plate in the adult stage and the presence of an entoneural system. Articulata first appeared in the fossil record during the Triassic period although other, now extinct crinoid groups, originated in the Ordovician. Characteristics Articulata exhibit pentamerous symmetry. The stalk, which consists of numerous disks held together by ligaments, supports a calyx or cup made of circlets of calcerous plates. In Comatulids, the stalk develops following the larval stage, but the juveniles shed all but the topmost disk to take up a free-living existence. Five often branched arms, which consist of articulated series of ossicles, extend from the oral plate and form the food-capture mechanism of Articula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bourgueticrinina
Bourgueticrinida is an order of crinoids that typically live deep in the ocean. Members of this order are attached to the seabed by a slender stalk and are known as sea lilies. While other groups of crinoids flourished during the Permian, bourgueticrinids along with other extant orders did not appear until the Triassic, following a mass extinction event in which nearly all crinoids died out. Taxonomy Bourgueticrinida has traditionally been viewed as an order of Articulata and a sister taxon to the order Comatulida, the feather stars. A study published in 2011 suggested that it should be renamed Bourgueticrinina and viewed as a suborder of Comatulida. Characteristics Sea lilies are crinoids with a calyx and five pairs of feather-like arms standing on a long stalk which is retained throughout the animal's life. This stalk is attached to the substrate by means of an enlarged, terminal disc or alternatively by means of several branching, irregular radicular cirri arising from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bourgueticrinida
Bourgueticrinida is an order of crinoids that typically live deep in the ocean. Members of this order are attached to the seabed by a slender stalk and are known as sea lilies. While other groups of crinoids flourished during the Permian, bourgueticrinids along with other extant orders did not appear until the Triassic, following a mass extinction event in which nearly all crinoids died out. Taxonomy Bourgueticrinida has traditionally been viewed as an order of Articulata and a sister taxon to the order Comatulida, the feather stars. A study published in 2011 suggested that it should be renamed Bourgueticrinina and viewed as a suborder of Comatulida. Characteristics Sea lilies are crinoids with a calyx and five pairs of feather-like arms standing on a long stalk which is retained throughout the animal's life. This stalk is attached to the substrate by means of an enlarged, terminal disc or alternatively by means of several branching, irregular radicular cirri arising from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathycrinidae
Bathycrinidae is a family of echinoderms in the class Crinoidea Crinoids are marine animals that make up the class Crinoidea. Crinoids that are attached to the sea bottom by a stalk in their adult form are commonly called sea lilies, while the unstalked forms are called feather stars or comatulids, which are .... It contains the following genera and species: * '' Bathycrinus'' Wyville Thomson, 1872 ** '' Bathycrinus aldrichianus'' Wyville Thomson, 1877 ** '' Bathycrinus australis'' AH Clark, 1907 ** '' Bathycrinus australocrucis'' McKnight, 1973 ** '' Bathycrinus carpenterii'' (Danielssen & Koren, 1877) ** '' Bathycrinus gracilis'' Wyville Thomson, 1877 ** '' Bathycrinus mendeleevi'' Mironov, 2008 * '' Discolocrinus'' Mironov, 2008 ** '' Discolocrinus thieli'' Mironov, 2008 * '' Monachocrinus'' AH Clark, 1919 ** '' Monachocrinus aotearoa'' McKnight, 1973 ** '' Monachocrinus caribbeus'' (AH Clark, 1908) ** '' Monachocrinus mortenseni'' Gislén, 1938 ** '' Monachocrinus paradoxu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oregonia Gracilis
''Oregonia gracilis'', commonly known as the graceful decorator crab, is a species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ... of crab belonging to the family Oregoniidae. Like other decorator crabs it habitually attaches other organisms to its back. The sessile organisms are attached to hooked setae that act as a sort of velcro attachment. This decoration provides visual and chemical camouflage thus reducing predation risk. Pacific halibut are a major predator of ''O. gracilis''. Other predators include octopus and sea otters. The main food source of ''O. gracilis'' is floating kelp and algae that they capture utilizing a waiting strategy in order to maintain cryptosis. Anatomy and physiology ''Oregonia gracilis'' have three body segments: head, thorax and abdomen. Like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pycnopodia Helianthoides
''Pycnopodia helianthoides'', commonly known as the sunflower sea star, is a large sea star found in the northeast Pacific. The only species of its genus, it is among the largest sea stars in the world, with a maximum arm span of . Adult sunflower sea stars usually have 16 to 24 limbs; their color can vary widely. They are predatory, feeding mostly on sea urchins, clams, snails, and other small invertebrates. Although the species had been widely distributed throughout the northeast Pacific, its population has rapidly declined since 2013. The sea star has been on IUCN list of endangered animals since 2021. Description Sunflower sea stars can grow to have an arm span of in diameter. They are the second-biggest sea star in the world, only second to the poorly known deep water '' Midgardia xandaros'', whose arm span is and its body is 2.6 cm (roughly 1 inch) wide, although ''P. helianthoides'' is the largest known echinoderm by mass. Growth of the sea star b ... [...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] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh B
Hugh may refer to: *Hugh (given name) Noblemen and clergy French * Hugh the Great (died 956), Duke of the Franks * Hugh Magnus of France (1007–1025), co-King of France under his father, Robert II * Hugh, Duke of Alsace (died 895), modern-day France * Hugh of Austrasia (7th century), Mayor of the Palace of Austrasia * Hugh I, Count of Angoulême (1183–1249) * Hugh II, Count of Angoulême (1221–1250) * Hugh III, Count of Angoulême (13th century) * Hugh IV, Count of Angoulême (1259–1303) * Hugh, Bishop of Avranches (11th century), France * Hugh I, Count of Blois (died 1248) * Hugh II, Count of Blois (died 1307) * Hugh of Brienne (1240–1296), Count of the medieval French County of Brienne * Hugh, Duke of Burgundy (d. 952) * Hugh I, Duke of Burgundy (1057–1093) * Hugh II, Duke of Burgundy (1084–1143) * Hugh III, Duke of Burgundy (1142–1192) * Hugh IV, Duke of Burgundy (1213–1272) * Hugh V, Duke of Burgundy (1294–1315) * Hugh Capet (939–996), King of France * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decorator Crab
Decorator crabs are crabs of several different species, belonging to the superfamily Majoidea (not all of which are decorators), that use materials from their environment to hide from, or ward off, predators. They decorate themselves by sticking mostly sedentary animals and plants to their bodies as camouflage, or if the attached organisms are noxious, to ward off predators through aposematism. History In 1889, William Bateson observed in detail the way that decorator crabs fix materials on their backs. He noted that "the whole proceeding is most human and purposeful", and that if a '' Stenorhynchus'' crab is cleaned, it will "''immediately'' begin to clothe itself again with the same care and precision as before". In his ''The Colours of Animals'' (1890), Edward Bagnall Poulton classified protective animal coloration into types such as warning colours and protective mimicry. He included self decoration under the heading "Adventitious Protection", quoting Bateson's account of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Florometra Serratissima
''Florometra serratissima'' is a species of crinoid or feather star in the family Antedonidae. It is found off the Pacific coast of North America, usually in deep water. Description Like other feather stars, ''F. serratissima'' has a stalk, a calyx and a set of arms. The mouth is located on the upper side at the centre of the calyx, with the anus nearby. Surrounding the calyx are five jointed limbs. These branch at the base to form ten or more arms, each of which has jointed appendages known as pinnules growing from it, in a feather-like fashion. The centre of each arm has an ambulacral groove down which food particles are moved by cilia to the mouth. When the arms are fully extended to either side, the crinoid may measure across. On the aboral (under) surface are clawlike cirri which grasp the seabed. This feather star is reddish-brown. Juveniles have a long stalk. Distribution ''F. serratissima'' is native to the Pacific coast of North America, its range extending from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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