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Cyprid
Barnacles are arthropods of the subclass Cirripedia in the subphylum Crustacea. They are related to crabs and lobsters, with similar nauplius larvae. Barnacles are exclusively marine invertebrates; many species live in shallow and tidal waters. Some 2,100 species have been described. Barnacle adults are sessile; most are suspension feeders with hard calcareous shells, but the Rhizocephala are specialized parasites of other crustaceans, with reduced bodies. Barnacles have existed since at least the mid-Carboniferous, some 325 million years ago. In folklore, barnacle geese were once held to emerge fully formed from goose barnacles. Both goose barnacles and the Chilean giant barnacle are fished and eaten. Barnacles are economically significant as biofouling on ships, where they cause hydrodynamic drag, reducing efficiency. Etymology The word "barnacle" is attested in the early 13th century as Middle English "bernekke" or "bernake", close to Old French "bernaque" and med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizocephala
Rhizocephala are derived barnacles that are parasitic castrators. Their hosts are mostly decapod crustaceans, but include Peracarida, mantis shrimps and thoracican barnacles. Their habitats range from the deep ocean to freshwater. Together with their sister groups Thoracica and Acrothoracica, they make up the subclass Cirripedia. Their body plan is uniquely reduced in an extreme adaptation to their parasitic lifestyle, and makes their relationship to other barnacles unrecognisable in the adult form. They also exhibit the most extreme sexual dimorphism of all animals. The females inject themselves into a host and take over their bodies, while the males inject themselves into a settled female and cease being independent organisms through the degeneration of all tissues except the ones responsible for spermatogenesis. The name Rhizocephala derives from the Ancient Greek roots (, "root") and (, "head"), describing the adult female, which mostly consists of a network of threa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrothoracica
The Acrothoracica are an infraclass of barnacles. Acrothoracicans bore into calcareous material such as mollusc shells, coral, crinoids or hardgrounds, producing a slit-like hole in the surface known by the trace fossil name '' Rogerella''. Acrothoracicans are typically smaller than other types of barnacle, being only a few millimetres in length. Being protected by the hard surfaces into which they have bored, they have no solid carapace of plates like other barnacles but have a soft, sac-like body fixed to the surface by a chitinous disc at the front of the head. They have from four to six pairs of feathery limbs, or "cirri", which they project out of their borings to catch drifting detritus for food. The mouthparts consist of mandibles, maxillules and maxillae. One pair of cirri is close to these while the others are at the other end of the body. The cyprid larva in Lithoglyptidae and Trypetesidae have a well-developed carapace which can completely enclose the body, a dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austromegabalanus Psittacus
''Austromegabalanus psittacus'', the giant barnacle or ' as it is known in Spanish, is a species of large barnacle native to the coasts of southern Peru, all of Chile and southern Argentina. It inhabits the littoral and intertidal zones of rocky shores and normally grows up to tall with a mineralized shell composed of calcite. The ''picoroco barnacle'' is used in Chilean cuisine and is one of the ingredients in curanto. Description ''Austromegabalanus psittacus'' is a large sessile barnacle that lives in groups on hard substrates. It has a tall cone-shaped carapace composed of twelve large plates made of calcite microcrystals which are cemented together. The basal disc is firmly cemented to a hard surface. It grows to a height of . There is an opening at the top with a hinged operculum through which the thoracic limbs known as "cirri" protrude. The general colour is dull white with purple and brown markings. Biology ''Austromegabalanus psittacus'' is a simultaneous herm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthropods including decapods (shrimps, prawns, crabs, lobsters and crayfish), seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans ( oligostracans and multicrustaceans). The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medieval Latin
Medieval Latin was the form of Literary Latin used in Roman Catholic Church, Roman Catholic Western Europe during the Middle Ages. It was also the administrative language in the former Western Roman Empire, Roman Provinces of Mauretania, Numidia (Roman province), Numidia and Africa (Roman province), Africa Proconsularis under the Vandals, the Exarchate of Africa, Byzantines and the Kingdom of Altava, Romano-Berber Kingdoms, until it declined after the Arab conquest of North Africa, Arab Conquest. Medieval Latin in Southern and Central Visigothic Kingdom, Visigothic Hispania, conquered by the Arabs immediately after North Africa, experienced a similar fate, only recovering its importance after the Reconquista by the Northern Christian Kingdoms. In this region it served as the primary written language, though local languages were also written to varying degrees. Latin functioned as the main medium of scholarly exchange, as the liturgical language of the Roman Catholic Church, Churc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofouling
Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that cause degradation to the primary purpose of that item. Such accumulation is referred to as '' epibiosis'' when the host surface is another organism and the relationship is not parasitic. Since biofouling can occur almost anywhere water is present, biofouling poses risks to a wide variety of objects such as boat hulls and equipment, medical devices and membranes, as well as to entire industries, such as paper manufacturing, food processing, underwater construction, and desalination plants. Anti-fouling is the ability of specifically designed materials (such as toxic biocide paints, or non-toxic paints) to remove or prevent biofouling. The buildup of biofouling on marine vessels poses a significant problem. In some instances, the hull str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle English
Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman Conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English period. Scholarly opinion varies, but the University of Valencia states the period when Middle English was spoken as being from 1150 to 1500. This stage of the development of the English language roughly coincided with the High Middle Ages, High and Late Middle Ages. Middle English saw significant changes to its vocabulary, grammar, pronunciation, and orthography. Writing conventions during the Middle English period varied widely. Examples of writing from this period that have survived show extensive regional variation. The more standardized Old English literary variety broke down and writing in English became fragmented and localized and was, for the most part, being improvised. By the end of the period (about 1470), and aided by the movabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old French
Old French (, , ; ) was the language spoken in most of the northern half of France approximately between the late 8th [2-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it was deemed no longer make to think of the varieties spoken in Gaul as Latin. Although a precise date can't be given, there is a general consensus (see Wright 1982, 1991, Lodge 1993) that an awareness of a vernacular, distinct from Latin, emerged at the end of the eighth century.] and mid-14th centuries. Rather than a unified Dialect#Dialect or language, language, Old French was a Dialect cluster, group of Romance languages, Romance dialects, Mutual intelligibility, mutually intelligible yet Dialect continuum, diverse. These dialects came to be collectively known as the , contrasting with the , the emerging Occitano-Romance languages of Occitania, now the south of France. The mid-14th century witnessed the emergence of Middle French, the lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chthamalus Stellatus
''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a genus of barnacles that is found along almost all non-boreal coasts of the northern hemisphere, as well as many regions in the southern hemisphere. These small barnacles have been studied in part because of the taxonomic confusion over a group of species that, by and large, are morphologically and ecologically quite similar. In recent years, molecular techniques have identified a number of cryptic species that have been subsequently confirmed by taxonomists using morphological measurements. Most recently the genus has been shown to be paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ..., with the genus ''Microeuraphia'' nested within ''Chthamalus''. Field Identification Identification of barnacles in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barnacle Goose
The barnacle goose (''Branta leucopsis'') is a species of goose that belongs to the genus ''Branta'' of black geese, which contains species with extensive black in the plumage, distinguishing them from the grey ''Anser (genus), Anser'' species. Despite its superficial similarity to the brant goose, genetic analysis has shown its closest relative is the cackling goose. Taxonomy and naming The barnacle goose was first Biological classification, classified taxonomically by Johann Matthäus Bechstein in 1803. ''Branta'' is a Latinised form of Old Norse ''Brandgás'', "burnt [black] goose" and the specific epithet is from the Ancient Greek ''leukos'' "white", and ''opsis'' "faced". In the mediaeval period, the barnacle goose and the similar brant goose were not distinguished, and Barnacle goose myth, were formerly believed to spawn from the goose barnacle. This gave rise to the English name of the barnacle goose and the scientific name of the brant goose. The barnacle myth can be date ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Online Etymology Dictionary
Etymonline, or ''Online Etymology Dictionary'', sometimes abbreviated as OED (not to be confused with the ''Oxford English Dictionary'', which the site often cites), is a free online dictionary that describes the etymology, origins of English language, English words, written and compiled by Douglas R. Harper. Description Douglas R. Harper is an American Civil War historian and copy editor for LNP Media Group. He compiled the etymology dictionary to record the history and evolution of more than 50,000 words, including slang and technical terms. The core of its etymology information stems from ''The Barnhart Dictionary of Etymology'' by Robert Barnhart, Ernest Klein's ''Comprehensive Etymology Dictionary of the English Language'', ''The Middle English Compendium'', ''The Oxford English Dictionary'', and the 1889–1902 ''Century Dictionary''. Harper also researches on digital archives. On the ''Etymonline'' homepage, Harper says that he considers himself "essentially and for the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
