|
Ophiurida
The Ophiurida are an order of echinoderms within the class Ophiuroidea. It includes the vast majority of living brittle stars. Characteristics Ophiurida have bursae for respiration and excretion, and dorsal and ventral arm shields are present and usually well developed. Arms are unbranched and incapable of coiling vertically. Most are five-armed, some with 4 or 6 arms as an abnormality, but others properly bear six or seven arms. The madreporite is on the oral surface. The digestive glands are entirely within the central disc. They move their arms side to side by means of ball-and-socket joints. Tropical species tend to contrast color from the environment, but most others prefer to blend in. These biochromes do not include echinochromes. Systematics and phylogeny There is currently no consensus as to the subdivision of the Ophiurida. The order has been divided into the following suborders and infraorders * Ophiomyxina * Ophiurina ** Hemieuryalina ** Chilophiurina ** G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiuroidea
Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician, about 500 million years ago. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiurida
The Ophiurida are an order of echinoderms within the class Ophiuroidea. It includes the vast majority of living brittle stars. Characteristics Ophiurida have bursae for respiration and excretion, and dorsal and ventral arm shields are present and usually well developed. Arms are unbranched and incapable of coiling vertically. Most are five-armed, some with 4 or 6 arms as an abnormality, but others properly bear six or seven arms. The madreporite is on the oral surface. The digestive glands are entirely within the central disc. They move their arms side to side by means of ball-and-socket joints. Tropical species tend to contrast color from the environment, but most others prefer to blend in. These biochromes do not include echinochromes. Systematics and phylogeny There is currently no consensus as to the subdivision of the Ophiurida. The order has been divided into the following suborders and infraorders * Ophiomyxina * Ophiurina ** Hemieuryalina ** Chilophiurina ** G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiura Ophiura
''Ophiura ophiura'' or the serpent star is a species of brittle star in the order Ophiurida. It is typically found on coastal seabeds around northwestern Europe. Description ''Ophiura ophiura'' has a circular central disc up to 35 mm (1.5 in) wide and five radially arranged, narrow arms each up to long. The general colour is mottled reddish-brown with a paler underside. Both the top and the underside of the disc are covered with calcareous plates. The arms are joined to the top rather than the edge of the disc and further small, articulating plates allow the arms to bend from side to side. Small spines on the arms lie flat against the surface. Four larger plates occur across the root of each arm with the outer pair having a comb-like edge, with 20 to 30 fine papillae in each.''Ophiura ophiura'' (Linnae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiurina
Ophiurina are a suborder of brittle stars containing the majority of living brittle star species. Systematics There is currently no consensus as to the subdivision of the Ophiurina (traditionally, the infraorders have been treated as suborders). It contains the genera Amphiura, Amphipholis, and Ophiacantha. The suborder has been divided into the following recent infraorders and families :Smith, A.B.; Paterson, G.L.J., Ophiuroid phylogeny and higher taxonomy: morphological, molecular and palaeontological perspectives. Zool. J. Linn. Soc. 114 (1995) * Ophiacanthidae Hemieuryalina * Hemieuryalidae Chilophiurina * Ophiuridae Gnathophiurina * Amphilepididae * Amphiuridae * Ophiothricidae * Ophiactidae *Ophionereididae *Ophiocomidae Ophiocomidae are a family of brittle stars of the suborder Ophiurina. Systematics and phylogeny Ophiocomidae has been placed (along with Ophionereididae) to the superfamily Ophiocomidea and infraorder Order ( la, ordo) is one of the eigh ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnathophiurina
The Gnathophiurina are a group of Ophiuroidea mostly treated as suborder (but at first as an order Gnathophiurida, and sometimes as infraorder of OphiurinaSmith, A.B.; Paterson, G.L.J. . Ophiuroid phylogeny and higher taxonomy: morphological, molecular and palaeontological perspectives. Zool. J. Linn. Soc. 114 (1995) or not used at all). Families * Amphilepididae Matsumoto, 1915 * Amphiuridae Ljungman, 1867 * Ophiactidae Matsumoto, 1915 * Ophiocomidae Ljungman, 1867 * Ophionereididae Ljungman, 1867 * Ophiothricidae Ljungman, 1867 References Gnathophiurina, Ophiurida {{ophiuroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiothricidae
Ophiotrichidae are a family of ophiurid brittle stars within the suborder Gnathophiurina. All have arms with delicate translucent, thorny spines. The arms are flexible in all directions. The jaws contain clusters of well-developed tooth papillae on the apex but not on the sides. There are no mouth papillae. Inside the mouth edge there is a second pair of tube feet. They show large radial shields. The dorsal surface of the disc is covered with spines and thorny towers. Systematics Ophiotrichidae contains the following genera: *'' Asteria'' (''nomen dubium'') *'' Gymnolophus'' Brock, 1888 *'' Lissophiothrix'' H.L. Clark, 1938 *'' Macrophiothrix'' H.L. Clark, 1938 *'' Ophioaethiops'' Brock, 1888 *'' Ophiocampsis'' Duncan, 1887 *'' Ophiocnemis'' Müller & Troschel, 1842 *'' Ophiogymna'' Ljungman, 1866 *'' Ophiolophus'' Marktanner-Turneretscher, 1887 *'' Ophiomaza'' Lyman, 1871 *'' Ophiophthirius'' Döderlein, 1898 *'' Ophiopsammium'' Lyman, 1874 *'' Ophiopteron'' Ludwig, 1888 *'' Op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (biology)
In biological classification, class ( la, classis) is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order. History The class as a distinct rank of biological classification having its own distinctive name (and not just called a ''top-level genus'' ''(genus summum)'') was first introduced by the French botanist Joseph Pitton de Tournefort in his classification of plants that appeared in his ''Eléments de botanique'', 1694. Insofar as a general definition of a class is available, it has historically been conceived as embracing taxa that combine a distinct ''grade'' of organization—i.e. a 'level of complexity', measured in terms of how differentiated their organ systems are into distinct regions or sub-organs—with a distinct ''type'' of construction, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated " soil organic matter". The detritus of aquatic ecosystems is organic material that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated " marine snow". Theory The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthparts adapted to rasping or grinding. Horses and other herbivores have wide flat teeth that are adapted to grinding grass, tree bark, and other tough plant material. A large percentage of herbivores have mutualistic gut flora that help them digest plant matter, which is more difficult to digest than animal prey. This flora is made up of cellulose-digesting protozoans or bacteria. Etymology Herbivore is the anglicized form of a modern Latin coinage, ''herbivora'', cited in Charles Lyell's 1830 '' Principles of Geology''.J.A. Simpson and E.S.C. Weiner, eds. (2000) ''The Oxford English Dictionary'', vol. 8, p. 155. Richard Owen employed the anglicized term in an 1854 work on fossil teeth and skeletons. ''Herbivora'' is derived from Latin ''her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_grazing_-_20050809.jpg "Click for more on -> Herbivore")