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Crabs Of The Atlantic Ocean
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 fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liocarcinus Vernalis
''Liocarcinus vernalis'', the grey swimming crab, is a small, shallow-water crab in the family Portunidae. ''L. vernalis'' was thought for a long time to be a predominantly Mediterranean Sea, Mediterranean species, but its known range was extended by a series of observations in the 1980s and 1990s. It ranges from West Africa to the southern North Sea. References Portunoidea Crustaceans of the Atlantic Ocean Crustaceans described in 1816 {{Crab-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oceana (non-profit Group)
Oceana, inc. is a 501(c)(3) nonprofit ocean conservation organization focused on influencing specific policy decisions on the national level to preserve and restore the world's oceans. It is headquartered in Washington D.C. with offices in Juneau, Alaska, Monterey, California, Fort Lauderdale, Florida, New York City, New York, Portland, Oregon, Toronto, Ontario, Mexico City, Madrid, Brussels, Copenhagen, Geneva, London, Manila, Belmopan, Brasilia, Santiago, and Lima, and it is the largest international advocacy group dedicated entirely to ocean conservation. Currently, Oceana has a staff of about 200 and 6,000 volunteers, and it has almost 50 million dollars of revenue (as of 2017). Oceana takes a multi-faceted approach to ocean conservation; It conducts its own scientific research in addition to making policy recommendations, lobbying for specific legislation, and filing and litigating lawsuits. History Oceana was established in 2001 by an international group of leading founda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japanese Spider Crab
The Japanese spider crab (''Macrocheira kaempferi'') is a species of marine crab that lives in the waters around Japan. It has the largest known leg-span of any arthropod. It goes through three main larval stages along with a prezoeal stage to grow to its great size. The genus ''Macrocheira'' contains multiple species. Two fossil species of this genus have been found, ''M. ginzanensis'' and ''M. yabei'', both from the Miocene of Japan. Its diverse taxonomic history is an important part of what these creatures are and how they evolved to be what they are today. They are sought by crab fisheries, and are considered a delicacy in Japan. Conservation efforts aim to protect these creatures and their population from overfishing. The Japanese spider crab is similar in appearance to the much smaller European spider crab ''(Maja squinado)'', though the latter, while within the same superfamily, belongs to a different family, the Majidae. Description The Japanese spider crab has the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pea Crab
The pea crab, ''Pinnotheres pisum'', is a small crab in the family Pinnotheridae that lives as a parasite in oysters, clams, mussels, and other species of bivalves. Description Pea crabs are small crustaceans about the size of a pea or dime, with a "smooth dorsal surface of the carapace, or upper exoskeleton". The exoskeleton of males is hard and circular and has eyes and antennae extending from their fronts, and the chelipeds are more robust in males than in females, which have more elongated chelipeds. The bodies of the female pea crabs are often translucent and show the inner organs and gonads as yellow and red, with the males being a "more yellowish-grey with patches of brown". Ecology The relationship between the pea crab and its host is one of parasitism, rather than commensalism, since the host may be harmed by the crab's feeding activities. The pea crab relies solely on its host for food, safety, and oxygen. Pea crabs have a variety of hosts, the most important of whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chela (organ)
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 a ... References Arthropod anatomy {{Arthropod-anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Biomaterialia
''Acta Biomaterialia'' is a monthly peer-reviewed scientific journal published by Elsevier. It is published on behalf of Acta Materialia, Inc., and is sponsored by ASM International and The Minerals, Metals & Materials Society. The journal was established in January 2005. The editor-in-chief is W.R. Wagner ( University of Pittsburgh). The journal covers research in biomaterials science, including the interrelationship of biomaterial structure and function from macroscale to nanoscale. Topical coverage includes biomedical and biocompatible materials. Formats of publication include original research reports, review papers, and rapid communications ("letters"). Abstracting and indexing ''Acta Biomaterialia'' is abstracted and indexed in: * Chemical Abstracts Service * EMBASE * EMBiology * Elsevier BIOBASE * MEDLINE/ PubMed * Materials Science Citation Index * Science Citation Index Expanded * Scopus According to the '' Journal Citation Reports'', the journal has a 2021 imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chitin
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chitin are produced each year in the biosphere. It is a primary component of cell walls in fungi (especially basidiomycetes and filamentous fungi), the exoskeletons of arthropods such as crustaceans and insects, the radulae, cephalopod beaks and gladii of molluscs and in some nematodes and diatoms. It is also synthesised by at least some fish and lissamphibians. Commercially, chitin is extracted from the shells of crabs, shrimps, shellfishes and lobsters, which are major by-products of the seafood industry. The structure of chitin is comparable to cellulose, forming crystalline nanofibrils or whiskers. It is functionally comparable to the protein keratin. Chitin has proved useful for several medicinal, industrial and biotechnological purpose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the larger kinds of exoskeletons are known as " shells". Examples of exoskeletons within animals include the arthropod exoskeleton shared by chelicerates, myriapods, crustaceans, and insects, as well as the shell of certain sponges and the mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some animals, such as the turtle, have both an endoskeleton and an exoskeleton. Role Exoskeletons contain rigid and resistant components that fulfill a set of functional roles in many animals including protection, excretion, sensing, support, feeding and acting as a barrier against desiccation in terrestrial organisms. Exoskeletons have a role in defense from pests and predators, support and in providing an attachment framewo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gecarcinus Quadratus (Nosara)
''Gecarcinus quadratus'', known as the red land crab, whitespot crab, Halloween crab, moon crab, Halloween moon crab, mouthless crab, or harlequin land crab, is a colourful land crab from the family Gecarcinidae. Distribution ''Gecarcinus quadratus'' is found in mangrove, sand dunes and rainforest along the Pacific coast from Mexico south to Panama. Previously it has also been reported from the Pacific coast of northwestern South America, but in 2014 this population was recognized as a separate species, '' G. nobili''. The taxonomy in relation to the Atlantic '' G. lateralis'' is disputed, with many considering ''G. quadratus'' and ''G. lateralis'' to be conspecific. Description The carapace of ''G. quadratus'' may reach a length of . It has a pair of largely purple claws, red-orange legs, and an almost entirely black carapace with a pair of yellow, orange, or reddish spots behind the eyes, and an additional pair of whitish spots on the central-lower carapace. Behaviour This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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