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Biomineralising Polychaetes
Biomineralising polychaetes are polychaetes that Biomineralization, biomineralize. The most important biomineralizing polychaetes are Serpulidae, serpulids, Sabellidae, sabellids and Cirratulidae, cirratulids. They secrete tubes of calcium carbonate. Serpulids have most advanced biomineralization system among the annelids. Serpulids possess very diverse tube ultrastructures. Serpulid tubes are composed of aragonite, calcite or mixture of both polymorphs. In addition to the tubes, some serpulid species secrete calcareous opercula. Some sabellids and cirratulids can secrete aragonitic tubes. Sabellid and cirratulid tubes have a spherulitic prismatic ultrastructure. There are thin organic sheets in serpulid tube mineral structures. These sheets have evolved as an adaptation to strengthen the mechanical properties of the tubes. References {{reflist Polychaetes Serpulidae Biomineralization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpula Israelitica
''Serpula'' (also known as calcareous tubeworm, serpulid tubeworm, fanworm, or plume worm) is a genus of Sessility (zoology), sessile, Marine (ocean), marine Annelida, annelid tube worm (body plan), tube worms that belongs to the family (biology), family Serpulidae. Serpulid worms are very similar to tube worms of the closely related Sabellidae, sabellid family, except that the former possess a cartilage, cartilaginous ''Operculum (bryozoa), operculum'' that occludes the entrance to their protective tube after the animal has withdrawn into it. The most distinctive feature of worms of the genus ''Serpula'' is their colorful fan-shaped "crown". The crown, used by these animals for Aquatic respiration, respiration and Filter feeder, alimentation, is the structure that is most commonly seen by scuba divers and other casual observers. Taxonomy Following is a brief description of the cladistics and taxonomic rank, taxonomic classification of ''Serpula'': ;Higher taxonomic ranks * The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerula Piloseta Tube Microstructure
''Glomerula'' is a genus of polychaete worm in the family Sabellidae. It differs from all other Sabellidae in having a calcareous tube and spinose setae. Only one living species, ''G. piloseta'', is known from Lizard Island, Great Barrier Reef, Australia. The oldest fossils of ''Glomerula'' are known from the Early Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ... and their tube microstructure has remained unchanged since then. References {{Taxonbar, from=Q2153277 Sabellida Extant Early Jurassic first appearances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychaete
Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the Alitta virens, sandworm or Alitta succinea, clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe Nereus (underwater vehicle), ''Nereus'' at the bottom of the Challenger Deep, the deepes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomineralization
Biomineralization, also written biomineralisation, is the process by which living organisms produce minerals, often to harden or stiffen existing tissues. Such tissues are called mineralized tissues. It is an extremely widespread phenomenon; all six taxonomic kingdoms contain members that are able to form minerals, and over 60 different minerals have been identified in organisms. Examples include silicates in algae and diatoms, carbonates in invertebrates, and calcium phosphates and carbonates in vertebrates. These minerals often form structural features such as sea shells and the bone in mammals and birds. Organisms have been producing mineralized skeletons for the past 550 million years. Calcium carbonates and calcium phosphates are usually crystalline, but silica organisms (sponges, diatoms...) are always non crystalline minerals. Other examples include copper, iron and gold deposits involving bacteria. Biologically formed minerals often have special uses such as magnetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpulidae
The Serpulidae are a family (biology), family of Sessility (zoology), sessile, tube worm (body plan), tube-building annelid worms in the class Polychaeta. The members of this family differ from other Sabellidae, sabellid tube worms in that they have a specialized Operculum (animal), operculum that blocks the entrance of their tubes when they withdraw into the tubes. In addition, serpulids secrete tubes of calcium carbonate. Serpulids are the most important biomineralising polychaetes, biomineralizers among annelids. About 300 species in the family Serpulidae are known, all but one of which live in saline waters. The earliest serpulids are known from the Permian (Wordian to lopingian, late Permian). The blood of most species of serpulid and sabellid worms contains the oxygen-binding pigment chlorocruorin. This is used to transport oxygen to the tissues. It has an affinity for carbon monoxide which is 570 times as strong as that of the haemoglobin found in human blood. Empty serpul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sabellidae
Sabellidae, or feather duster worms, are a family of marine polychaete tube worms characterized by protruding feathery branchiae. Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell. Unlike the other sabellids, the genus '' Glomerula'' secretes a tube of calcium carbonate instead. Sabellidae can be found in subtidal habitats around the world. Their oldest fossils are known from the Early Jurassic. Characteristics Feather-duster worms have a crown of feeding appendages or radioles in two fan-shaped clusters projecting from their tubes when under water. Each radiole has paired side branches making a two-edged comb for filter feeding. Most species have a narrow collar below the head. The body segments are smooth and lack parapodia. The usually eight thoracic segments bear capillaries dorsally and hooked chaetae (bristles) ventrally. The abdominal segments are similar, but with the position of the capillaries and chaetae reversed. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirratulidae
Cirratulidae is a family of marine polychaete worms. Members of the family are found worldwide, mostly living in mud or rock crevices. Most are deposit feeders, but some graze on algae or are suspension feeders. Description Cirratulids vary in size from one to twenty centimetres long. They are mostly burrowers in soft sediments but some live in rock crevices. The head is conical or wedge-shaped and has no antennae. The body is generally cylindrical, tapering at both ends. Cirratulids are characterised by a large number of simple elongate filaments along the body. Some of these occur as an anterior cluster of tentacles, grooved for deposit-feeding, but the majority, the branchiae, are found one pair per segment, and do not have grooves. The chaetae (bristles) are simple capillaries, usually with hooks, and emerge directly from the body wall. There are no anal cirri (slender sensory appendages). The worm is usually buried with only the writhing branchial filaments visible. Some ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polycha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aragonite
Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments. The crystal lattice of aragonite differs from that of calcite, resulting in a different crystal shape, an orthorhombic crystal system with acicular crystal. Repeated twinning results in pseudo-hexagonal forms. Aragonite may be columnar or fibrous, occasionally in branching helictitic forms called ''flos-ferri'' ("flowers of iron") from their association with the ores at the Carinthian iron mines. Occurrence The type location for aragonite is Molina de Aragón in the Province of Guadalajara in Castilla-La Mancha, Spain, for which it was named in 1797. Aragonite is found in this locality as cyclic twins inside gypsum and marls of the Keuper facies of the Triassic. This type of arago ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for Lime (material), lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeology, archaeologists and stone trade pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
