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Venomous Fish
Venomous fish are species of fish which produce strong mixtures of toxins harmful to humans (called venom) which they deliberately deliver by means of a bite, sting, or stab, resulting in an envenomation. As a contrast, poisonous fish also produce a strong toxin, but they do not bite, sting, or stab to deliver the toxin, instead being poisonous to eat because the human digestive system does not destroy the toxin they contain in their bodies. Venomous fish do not necessarily cause poisoning if they are eaten, as the digestive system often destroys the venom.Poisonous vs. Venomous fish: What’s the difference? Reef Biosearch. Retrieved 17 July 2009. There are at least 1200 species of venomous fish, Smith WL and Wheeler WC (2006 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reef0915 - Flickr - NOAA Photo Library
A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock outcrops, etc.—but there are also reefs such as the coral reefs of tropical waters formed by biotic processes dominated by corals and coralline algae, and artificial reefs such as shipwrecks and other anthropogenic underwater structures may occur intentionally or as the result of an accident, and sometimes have a designed role in enhancing the physical complexity of featureless sand bottoms, to attract a more diverse assemblage of organisms. Reefs are often quite near to the surface, but not all definitions require this. Earth's largest coral reef system is the Great Barrier Reef in Australia, at a length of over . Biotic There is a variety of biotic reef types, including oyster reefs and sponge reefs, but the most massive and widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coral Reef Fish
Coral reef fish are fish which live amongst or in close relation to coral reefs. Coral reefs form complex ecosystems with tremendous biodiversity. Among the myriad inhabitants, the fish stand out as colourful and interesting to watch. Hundreds of species can exist in a small area of a healthy reef, many of them hidden or well camouflaged. Reef fish have developed many ingenious specialisations adapted to survival on the reefs. Coral reefs occupy less than 1% of the surface area of the world oceans, but provide a home for 25% of all marine fish species. Reef habitats are a sharp contrast to the open water habitats that make up the other 99% of the world oceans. However, loss and degradation of coral reef habitat, increasing pollution, and overfishing including the use of destructive fishing practices, are threatening the survival of the coral reefs and the associated reef fish. Overview Coral reefs are the result of millions of years of coevolution among algae, invertebrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phospholipase
A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. Acids trigger the release of bound calcium from cellular stores and the consequent increase in free cytosolic Ca2+, an essential step in calcium signaling to regulate intracellular processes. There are four major classes, termed A, B, C, and D, which are distinguished by the type of reaction which they catalyze: *Phospholipase A **Phospholipase A1 – cleaves the ''sn''-1 acyl chain (where ''sn'' refers to stereospecific numbering). **Phospholipase A2 – cleaves the ''sn''-2 acyl chain, releasing arachidonic acid. * Phospholipase B – cleaves both ''sn''-1 and ''sn''-2 acyl chains; this enzyme is also known as a lysophospholipase. *Phospholipase C – cleaves before the phosphate, releasing diacylglycerol and a phosphate-containing head group. PLCs play a central role in signal transduction, releasing the second messenger inositol triphosphate. * Phospholipase D †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enkephalin
An enkephalin is a pentapeptide involved in regulating nociception in the body. The enkephalins are termed endogenous ligands, as they are internally derived and bind to the body's opioid receptors. Discovered in 1975, two forms of enkephalin have been found, one containing leucine ("leu"), and the other containing methionine ("met"). Both are products of the proenkephalin gene. * Met-enkephalin is Tyr-Gly-Gly-Phe-Met. * Leu-enkephalin has Tyr-Gly-Gly-Phe-Leu. Endogenous opioid peptides There are three well-characterized families of opioid peptides produced by the body: enkephalins, B-endorphin, and dynorphins. The met-enkephalin peptide sequence is coded for by the enkephalin gene; the leu-enkephalin peptide sequence is coded for by both the enkephalin gene and the dynorphin gene. The proopiomelanocortin gene (POMC) also contains the met-enkephalin sequence on the N-terminus of beta-endorphin, but the endorphin peptide is not processed into enkephalin. Effects on stress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blenniiformes
Blenny (from the Greek and , mucus, slime) is a common name for many types of fish, including several families of percomorph marine, brackish, and some freshwater fish sharing similar morphology and behaviour. Six families are considered "true blennies", grouped under the order Blenniiformes; its members are referred to as blenniiformids. About 151 genera and nearly 900 species have been described within the order. The order was formerly classified as a suborder of the Perciformes but the 5th Edition of ''Fishes of the World'' divided the Perciformes into a number of new orders and the Blenniiformes were placed in the percomorph clade Ovalentaria alongside the such taxa as Cichliformes, Mugiliformes and Gobiesociformes. Families The six "true blenny" families are: * Blenniidae Rafinesque, 1810 - combtooth blennies, including the sabre-toothed blennies * Chaenopsidae Gill, 1865 - pikeblennies, tubeblennies and flagblennies * Clinidae Swainson, 1839 - clinids, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Pacific Underwater Medicine Society
The South Pacific Underwater Medicine Society (SPUMS) is a primary source of information for diving and hyperbaric medicine physiology worldwide. History The SPUMS was founded on May 3, 1971 in the wardroom of HMAS PENGUIN. The founding members of SPUMS were Carl Edmonds, Bob Thomas, Douglas Walker, Ian Unsworth, and Cedric Deal and they were joined by approximately 20 others as "charter members". The society was incorporated in 1990. Purpose The aims of SPUMS have never changed since its inception: * To promote and facilitate the study of all aspects of underwater and hyperbaric medicine; * To provide information on underwater and hyperbaric medicine; * To publish a journal and; * To convene members of each Society annually at a scientific conference. Training SPUMS offers a Diploma of Diving and Hyperbaric Medicine. This certification, was the first non-naval certification and for years the only postgraduate education available. The first Diplomas by examination were a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artery
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pulmonary and the umbilical arteries, which carry deoxygenated blood to the organs that oxygenate it (lungs and placenta, respectively). The effective arterial blood volume is that extracellular fluid which fills the arterial system. The arteries are part of the circulatory system, that is responsible for the delivery of oxygen and nutrients to all cells, as well as the removal of carbon dioxide and waste products, the maintenance of optimum blood pH, and the circulation of proteins and cells of the immune system. Arteries contrast with veins, which carry blood back towards the heart. Structure The anatomy of arteries can be separated into gross anatomy, at the macroscopic level, and microanatomy, which must be studied with a microscop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz. Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Somewhat more rarely, sand may be composed of calciu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stinger
A stinger (or sting) is a sharp organ found in various animals (typically insects and other arthropods) capable of injecting venom, usually by piercing the epidermis of another animal. An insect sting is complicated by its introduction of venom, although not all stings are venomous. Bites, which can introduce saliva as well as additional pathogens and diseases, are often confused with stings, and vice versa. Specific components of venom are believed to give rise to an allergic reaction, which in turn produces skin lesions that may vary from a small itching weal, or slightly elevated area of the skin, to large areas of inflamed skin covered by vesicles and crusted lesions. Stinging insects produce a painful swelling of the skin, the severity of the lesion varying according to the location of the sting, the identity of the insect and the sensitivity of the subject. Many species of bees and wasps have two poison glands, one gland secreting a toxin in which formic acid is one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stingray Injury
A stingray injury is caused by the venomous tail spines, stingers or dermal denticles of rays in the order Myliobatiformes, most significantly those belonging to the families Dasyatidae, Urotrygonidae, Urolophidae, and Potamotrygonidae. Stingrays generally do not attack aggressively or even actively defend themselves. When threatened, their primary reaction is to swim away. However, when attacked by predators or stepped on, the stinger in their tail is whipped up. This is normally ineffective against sharks, their main predator. Depending on the size of the stingray, humans are usually stung in the lower limb region. Stings usually occur when swimmers or divers accidentally step on a stingray, but a human is less likely to be stung by simply brushing against the stinger. Those who enter waters with large populations of stingrays are advised to slide their feet through the sand rather than taking normal steps, as the rays detect the vibrations in the sand and swim away. There ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stingray
Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwater stingray), Urolophidae (stingarees), Urotrygonidae (round rays), Dasyatidae (whiptail stingrays), Potamotrygonidae (river stingrays), Gymnuridae (butterfly rays) and Myliobatidae (eagle rays). There are about 220 known stingray species organized into 29 genera. Stingrays are common in coastal tropical and subtropical marine waters throughout the world. Some species, such as the thorntail stingray (''Dasyatis thetidis''), are found in warmer temperate oceans and others, such as the deepwater stingray (''Plesiobatis daviesi''), are found in the deep ocean. The river stingrays and a number of whiptail stingrays (such as the Niger stingray (''Fontitrygon garouaensis'')) are restricted to fresh water. Most myliobatoids are demersa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Market
A fish market is a marketplace for selling fish and fish products. It can be dedicated to wholesale trade between fishermen and fish merchants, or to the sale of seafood to individual consumers, or to both. Retail fish markets, a type of wet market, often sell street food as well. Fish markets range in size from small fish stalls to large ones such as the great Tsukiji fish market in Tokyo, which turns over about 660,000 tonnes a year.Clover C (2008''The End of the Line: How Overfishing Is Changing the World and What We Eat''Page 165. University of California Press, . The term ''fish market'' can also refer to the process of fish marketing in general, but this article is concerned with physical marketplaces. __TOC__ History and development Fish markets were known in antiquity.Rauch JE and Casella A (2001''Networks and markets''Page 157. Russell Sage Foundation, . They served as a public space where large numbers of people could gather and discuss current events and local polit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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