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Valve (mollusc)
A valve is each articulating part of the shell of a Mollusca, mollusc or another multi-shelled animal such as Brachiopod, brachiopods and some Crustacean, crustaceans. Each part is known as a valve or in the case of Chiton, chitons, a "plate". Members of two Class (biology), classes of molluscs, the Bivalvia (clams) and the Polyplacophora (chitons), have valves. Species within one family of very unusual small sea snails, marine (ocean), marine opisthobranch gastropods in the family Juliidae, also have two articulating shells or valves, which resemble those of a bivalve. This exceptional family is commonly known as the bivalved gastropods. Gastropods in general are sometimes called "univalves", because in those that have a shell, the shell is usually in one part. Chitons The valves of chitons are eight dorsum (biology), dorsal, wiktionary:articulated, articulated shell plates, which are frequently coloured and sculpted. After death the girdle that holds the plates together disin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiton Tuberculatus Plates
Chitons () are marine (ocean), marine molluscs of varying size in the class (biology), class Polyplacophora ( ), formerly known as Amphineura. About 940 Extant taxon, extant and 430 fossil species are recognized. They are also sometimes known as sea cradles or coat-of-mail shells or suck-rocks, or more formally as loricates, polyplacophorans, and occasionally as polyplacophores. Chitons have a shell composed of eight separate shell plates or Valve (mollusc), valves. These plates overlap slightly at the front and back edges, and yet articulate well with one another. Because of this, the shell provides protection at the same time as permitting the chiton to flex upward when needed for locomotion over uneven surfaces, and even allows the animal to curl up into a ball when dislodged from rocks. The shell plates are encircled by a skirt known as a girdle (chiton), girdle. Habitat Chitons live worldwide, from cold waters through to the tropics. They live on hard surfaces, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abra Alba 2
Abra may refer to: Places * Abra, Burkina Faso * Abra, Ivory Coast * Abra (province), a province of the Philippines ** Abra's at-large congressional district ** Legislative district of Abra * Abra de Ilog, a municipality of Occidental Mindoro in the Philippines * Abra River, in the Philippines * Abra, Lebanon, a municipality of Lebanon * Abra, Pakistan * Abra Channel, connecting the Magellan Strait with the Pacific Ocean * El Abra, an archaeological site in Colombia People * Abra (name), a given name and a surname * Abra (Samma tribe) or Abro, an ethnic group in Pakistan Other uses * American Boat Racing Association * Abra (boat), a type of river-crossing boat in Dubai, United Arab Emirates * ''Abra'' (bivalve), a genus of Semelidae clams * ABRA (gene), a human gene located on chromosome 8 * Abra Group, holding company of Avianca Group, GOL Linhas Aéreas Inteligentes and Wamos Air * Abra (company), an American financial services and technology company o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamanovalva
''Berthelinia'' is a genus of gastropod belonging to the family Juliidae.MolluscaBase eds. (2021). MolluscaBase. Berthelinia Crosse, 1875. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=415113 on 2021-06-09 The genus has almost cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en .... Species: *'' Berthelinia australis'' *'' Berthelinia babai'' *'' Berthelinia caribbea'' *'' Berthelinia chloris'' *'' Berthelinia corallensis'' *'' Berthelinia darwini'' *'' Berthelinia elegans'' *'' Berthelinia fijiensis'' *'' Berthelinia ganapati'' *'' Berthelinia limax'' * † '' Berthelinia oligocaenica'' Janssen, 1979 Lozouet (P.) & Maestrati (P.), 2012 - Le contenu paléontologique. Mollusques. In : L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julia (genus)
Julia is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the superfamily Oxynooidea. ''Julia'' is the type genus of the family Juliidae. Description As Tryon (1884) Tryon G. W. Jr. (1884)''Structural and systematic conchology: an introduction to the study of the Mollusca. Volume III'' Philadelphia, published by the authorp. 267 wrote in his description of the genus ''Julia'': the shell is oblong, thick, and cordiform. The valves are closed, the margins entire and the valves are inequilateral. The lunule is deep circular, projecting into the interior of the right valve, the left valve is in the same place furnished with dentiform tubercles. The hinge line is simple and arched. The ligament is external and narrow. There are two muscle scars which are unequal and subcentral. These animals have two valves, and the soft parts can be completely withdrawn inside the shell. de Bruyne R. H. (2004). ''Encyklopedie ulit a lastur''. Rebo Productions, 336 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacoglossa
Sacoglossa are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia known as sacoglossans. There are 284 valid species recognized within this superorder. Sacoglossans live by ingesting the cellular contents of algae, hence they are sometimes called "sap-sucking sea slugs". Some sacoglossans simply digest the fluid which they suck from the algae, but in some other species, the slugs sequester and use within their own tissues living chloroplasts from the algae they eat, a very unusual phenomenon known as kleptoplasty, for the "stolen" plastids. This earns them the title of the "solar-powered sea slugs", and makes them unique among metazoan organisms, for otherwise kleptoplasty is known only among other euthyneurans and single-celled protists. The Sacoglossa are divided into two clades - the shelled families (Oxynoacea) and the shell-less families (Plakobranchacea). The four families of shelled species are Cylindrobul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of many gastropods, including snails, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, ostracum, is typically made of calcium carbonate (CaCO3) precipitated into an organic matrix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusks
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater and even terrestrial species. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known extant invertebrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues. Chemistry Calcium carbonate shares the typical properties of other carbonates. Notably, it: *reacts with acids, releasing carbonic acid which quickly disintegrates into carbon dioxide and water: : *releases carbon dioxide upon heating, called a thermal decomposition reaction, or calcination (to above 840 °C in the case of ), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
An operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails, including the Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture (mollusc), aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture (mollusc), aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which are not capable of closing the shell aperture. Opercula have sometimes been modifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
