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Helmet Crab
''Corystes cassivelaunus'', the masked crab, helmet crab or sand crab, is a burrowing crab of the North Atlantic and North Sea from Portugal to Norway, which also occurs in the Mediterranean Sea. It may grow up to long (carapace length). The name "masked crab" derives from the patterns on the carapace which resemble a human face (a case of pareidolia), in a similar manner to ''heikegani''. It is the only species in the genus ''Corystes''. ''C. cassivelaunus'' lives buried in sandy substrates, where it feeds on the infaunal invertebrates such as polychaete worms and bivalve molluscs. It uses its two antennae to form a breathing tube that allows oxygenated water down into the substrate. The cheliped A chela ()also called a claw, nipper, or pinceris a pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are called chelipeds. ...s of males are much longer than ...
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Louis Augustin Guillaume Bosc
Louis Augustin Guillaume Bosc (or Louis-Augustin Bosc d'Antic) (29 January 1759 – 10 July 1828) was a French botanist, invertebrate zoologist, and entomologist. Biography Bosc was born in Paris, the son of Paul Bosc d’Antic, a medical doctor and chemist. He studied at Dijon, where he was the pupil of botanist Jean-François Durande and chemist Louis-Bernard Guyton-Morveau. Being unable to become an artilleryman, he worked initially for the office of the controller general and then for the comptroller of the postal service. In time he took courses in botany under Antoine-Laurent de Jussieu and met botanist René Desfontaines and naturalist Pierre Marie Auguste Broussonet. He also took up with Jean Marie Roland and Madame Roland and formed a lasting relationship with Danish entomologist Johan Christian Fabricius. While working for the postal service he carried out work on natural history, publishing a description of a new species of fly, Orthezia characais, and a method of pr ...
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Heikegani
is a species of crab native to Japan, with a shell that bears a pattern resembling a human face (a case of pareidolia) which is interpreted to be the face of an angry samurai hence the nickname samurai crab. The crabs are named after the once powerful Taira clan which dominated medieval Japan, commonly known as the Heike. It is believed that these crabs are reincarnations of the Heike warriors defeated at the naval Battle of Dan-no-ura as told in ''The Tale of the Heike''. While the crabs are edible, they are not eaten by most Japanese. Origin of the carapace pattern Heikegani were used by Carl Sagan in his popular science television series '' Cosmos: A Personal Voyage'' as an example of unintentional artificial selection, an interpretation originally published by Julian Huxley in 1952. According to this hypothesis, the crabs with shells resembling samurai were thrown back to the sea by fishermen out of respect for the Heike warriors, while those not resembling samurai ...
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Crustaceans Of The Atlantic Ocean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, 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 emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by their ...
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Crabs
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ...
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University Of Amsterdam
The University of Amsterdam (abbreviated as UvA, nl, Universiteit van Amsterdam) is a public research university located in Amsterdam, Netherlands. The UvA is one of two large, publicly funded research universities in the city, the other being the Vrije Universiteit Amsterdam (VU). Established in 1632 by municipal authorities and later renamed for the city of Amsterdam, the University of Amsterdam is the third-oldest university in the Netherlands. It is one of the largest research universities in Europe with 31,186 students, 4,794 staff, 1,340 PhD students and an annual budget of €600 million. It is the largest university in the Netherlands by enrollment. The main campus is located in central Amsterdam, with a few faculties located in adjacent boroughs. The university is organised into seven faculties: Humanities, Social and Behavioural Sciences, Economics and Business, Science, Law, Medicine, Dentistry. The University of Amsterdam has produced six Nobel Laureates and fiv ...
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Cheliped
A chela ()also called a claw, nipper, or pinceris a pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are called chelipeds. Another name is ''claw'' because most chelae are curved and have a sharp point like a claw. Chelae can be present at the tips of arthropod legs as well as their pedipalps. Chelae are distinct from spider chelicerae in that they do not contain venomous glands and cannot distribute venom. See also * Pincer (biology) * Pincer (tool) Pincers are a hand tool used in many situations where a mechanical advantage is required to pinch, cut or pull an object. Pincers are first-class levers, but differ from pliers in that the concentration of force is either to a point, or to an ... References Arthropod anatomy {{Arthropod-anatomy-stub ...
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Sefton Coast
Sefton Coast is a 4605.3 hectare (11379.9 acre) Site of special scientific interest which stretches for 12 miles (20 km) between Southport and Waterloo, which is end location of Crosby Beach. The site was notified in 2000 for both its biological and geological features. The coast has species such as grass of Parnassus, wild orchids, rare butterflies, sand lizards, natterjack toads and waders. Sefton Coast includes Crosby beach which is also the site of an art installation by Antony Gormley, called ''Another Place''. Further north is the National Trust site of Formby Point containing pinewoods and sand dunes. The whole of the coastline here is managed as a Special Area of Conservation(SAC) for its important wildlife reserves by Sefton Coast Partnership. The pine woods at Victoria Road have been established as a National Trust reserve for the red squirrel, listed on the endangered species list. Formby is one of several sites in Britain where the red squirrel can still b ...
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Oxygenation (environmental)
Environmental oxygenation can be important to the sustainability of a particular ecosystem. Insufficient oxygen ( environmental hypoxia) may occur in bodies of water such as ponds and rivers, tending to suppress the presence of aerobic organisms such as fish. Deoxygenation increases the relative population of anaerobic organisms such as plants and some bacteria, resulting in fish kills and other adverse events. The net effect is to alter the balance of nature by increasing the concentration of anaerobic over aerobic species. Oxygenation by water aeration can be part of the environmental remediation of a usually stagnant body of water. For example, Bubbly Creek in Chicago, Illinois, was hypoxic (deficient in oxygen) due to its use as an open sewer by Chicago's meat packing industry but has been oxygenated by introducing compressed air into its waters, increasing the fish population. A similar technique has previously been used in the Thames. Dissolved oxygen (DO) is measured in ...
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Antenna (biology)
Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments. While they are typically sensory organs, the exact nature of what they sense and how they sense it is not the same in all groups. Functions may variously include sensing touch, air motion, heat, vibration (sound), and especially smell or taste. Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring the arthropod to a substrate. Larval arthropods have antennae that differ from those of the adult. Many crustaceans, for example, have free-swimming larvae that use their antennae for swimming. Antennae can also locate other group members if the insect lives in a group, like the ant. The common ancestor of all arthropods likely had one pair of uniramous (unbranched ...
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Bivalvia
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ... that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into Ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they a ...
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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 ...
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Invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelids, echinoderms and cnidarians. The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxa have a greater number and variety of species than the entire subphylum of Vertebrata. Invertebrates vary widely in size, from 50  μm (0.002 in) rotifers to the 9–10 m (30–33 ft) colossal squid. Some so-called invertebrates, such as the Tunicata and Cephalochordata, are more closely related to vertebrates than to other invertebrates. This makes the invertebrates paraphyletic, so the term has little meaning in taxonomy. Etymology The word "invertebrate" comes from the Latin word ''vertebra'', whi ...
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