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Rotenone
Rotenone is an odorless, colorless, crystalline isoflavone used as a broad-spectrum insecticide, piscicide, and pesticide. It occurs naturally in the seeds and stems of several plants, such as the jicama vine plant, and the roots of several members of Fabaceae. It was the first described member of the family of chemical compounds known as rotenoids. Discovery The earliest record of the now-known rotenone-containing plants used for killing leaf-eating caterpillars was in 1848, and for centuries, the same plants were used to poison fish. The active chemical component was first isolated in 1895 by a French botanist, Emmanuel Geoffroy, who called it ''nicouline'', from a specimen of ''Robinia nicou'', now called ''Lonchocarpus nicou'', while traveling in French Guiana. He wrote about this research in his thesis, published in 1895 after his death from a parasitic disease. In 1902 Kazuo Nagai, Japanese chemical engineer of the Government-General of Taiwan, isolated a pure crystalline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscicide
A piscicide is a chemical substance which is poisonous to fish. The primary use for piscicides is to eliminate a dominant species of fish in a body of water, as the first step in attempting to populate the body of water with a different fish. They are also used to combat parasitic and invasive species of fish. Examples of piscicides include rotenone, saponins, TFM, niclosamide and Antimycin A (Fintrol).Susan J. Clearwater, Chris W. Hickey, Michael L. Martin Overview of potential piscicides and molluscicides for controlling aquatic pest species in New Zealand' Science & Technical Publishing 2008 Plant-based piscicides Historically, fishing techniques of indigenous people around the world have frequently included the use of plant-based piscicides. Many of these plants are natural sources of rotenone and saponins. The genera ''Tephrosia'', ''Wikstroemia'', and ''Barringtonia'' are well known as fish poisons. See also *Cyanide fishing In respect of fishing techniques, cyanide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotenoid
Rotenoids are naturally occurring substances containing a cis-fused tetrahydrochromeno ,4-bhromene nucleus. Many have insecticidal activity, such as the prototypical member of the family, rotenone. Rotenoids are related to the isoflavones. Natural occurrences Many plants in the subfamily Faboideae contain rotenoids. Rotenoids can be found in ''Lonchocarpus sp''. Deguelin and tephrosin can be found in ''Tephrosia vogelii''. 6'-O-β-D-glucopyranosyl-12a-hydroxydalpanol can be found in the fruits of ''Amorpha fruticosa''. Elliptol, 12-deoxo-12alpha-methoxyelliptone, 6-methoxy-6a,12a-dehydrodeguelin, 6a,12a-dehydrodeguelin, 6-hydroxy-6a,12a-dehydrodeguelin, 6-oxo-6a,12a-dehydrodeguelin and 12a-hydroxyelliptone can be isolated from the twigs of ''Millettia duchesnei''. Deguelin, dehydrodeguelin, rotenol, rotenone, tephrosin and sumatrol can be found in ''Indigofera tinctoria''. 6aα,12aα-12a-hydroxyelliptone can be found in the stems of ''Derris trifoliata''. Amorphol, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lonchocarpus Nicou
''Lonchocarpus'' is a plant genus in the legume family ( Fabaceae). The species are called lancepods due to their fruit resembling an ornate lance tip or a few beads on a string. ''Cubé'' resin is produced from the roots of '' L. urucu'' and namely ' L. utilis'' (''cubé''). It contains enough of the toxic rotenoids rotenone and deguelin to be used as an insecticide and piscicide. As these are naturally occurring compounds, they were formerly used in organic farming. Since it is highly unselective and kills useful, as well as pest, animals, it is considered harmful to the environment today. Also, chronic exposure to rotenone and deguelin seems to increase the risk of Parkinson's disease even in mammals, for which these compounds are less acutely toxic than for fish and insects. On the other hand, deguelin might be useful in cancer therapy if it can be applied directly into tumors, and ''Lonchocarpus'' root is used to a probably insignificant extent by indigenous peoples as an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derris Elliptica
''Derris eliptica'' is a species of leguminous plant from Southeast Asia and the southwest Pacific islands, including New Guinea. The roots of ''D. elliptica'' contain rotenone, a strong insecticide and fish poison. Also known as ''derris powder'' and ''tuba root'' (in Indonesia), it was formerly used as an organic insecticide used to control pests on crops such as peas. However, due to studies revealing the extreme toxicity of rotenone to which the powder is often refined, it is unsafe: in spite of its popularity with organic growers. Derris root, when crushed, releases rotenone. Some native residents of Fiji and New Guinea practice a form of fishing in which they crush the roots and throw them into the water. The stunned or killed fish float to the surface where they can be easily reached. Despite its toxicity, ''Derris'' is used as a food plant by Lepidopteran larvae including '' Batrachedra amydraula''. Subspecies The following subspecies are listed:Roskov Y., Kunze T., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It is commonly used as a solvent in laboratories and as a starting fluid for some engines. It was formerly used as a general anesthetic, until non-flammable drugs were developed, such as halothane. It has been used as a recreational drug to cause intoxication. Production Most diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make more ether if the need arises. Vapor-phase dehydration of ethanol over some alumina catalysts can give diethyl ether yields of up to 95%. Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol is mixed with a stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and neophyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely, non-exponential) decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, ''half-life period'', dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to ''half-life'' in the early 1950s. Rutherford applied the principle of a radioactive element's half-life in studies of age determination of rocks by measuring the decay period of radium to lead-206. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Matter
Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have come from the feces and remains of organisms such as plants and animals. Organic molecules can also be made by chemical reactions that do not involve life. Basic structures are created from cellulose, tannin, cutin, and lignin, along with other various proteins, lipids, and carbohydrates. Organic matter is very important in the movement of nutrients in the environment and plays a role in water retention on the surface of the planet. Formation Living organisms are composed of organic compounds. In life, they secrete or excrete organic material into their environment, shed body parts such as leaves and roots and after organisms die, their bodies are broken down by bacterial and fungal action. Larger molecules of organic matter can be formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stone Moroko
The stone moroko (''Pseudorasbora parva''), also known as the topmouth gudgeon, is a fish belonging to the Cyprinid family, native to Asia, but introduced and now considered an invasive species in Europe and North America. The fish's size is rarely above 8 cm and usually 2 to 7.5 cm long. Invasive species In Europe, ''P. parva'' is included since 2016 in the list of Invasive Alien Species of Union concern (the Union list). This implies that this species cannot be imported, bred, transported, commercialized, or intentionally released into the environment in the whole of the European Union. The fish was introduced in the 1960s into ponds in Nucet, Dâmbovița County, Romania and it made its way into Danube, then spreading throughout Europe. They pose danger to other species such as the sunbleaks (''Leucaspius delineatus''). They are the carrier of a parasite (''Sphaerothecum destruens'') that is not damaging to the topmouth gudgeon, but attacks other fishes like the sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pumpkinseed
The pumpkinseed (''Lepomis gibbosus''), also referred to as pond perch, common sunfish, punkie, sunfish, sunny, and kivver, is a small/medium-sized North American freshwater fish of the genus ''Lepomis'' (true sunfishes), from family Centrarchidae (sunfishes, crappies and black basses) in the order Perciformes. Distribution and habitat The pumpkinseed's natural range in North America is from New Brunswick down the east coast to South Carolina. It then runs inland to the middle of North America, and extends through Iowa and back through Pennsylvania. Pumpkinseed sunfish have however been introduced throughout most of North America. They can now be found from Washington and Oregon on the Pacific Coast to Georgia on the Atlantic Coast. Yet they are primarily found in the northeastern United States and more rarely in the south-central or southwestern region of the continent. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Pike
The northern pike (''Esox lucius'') is a species of carnivorous fish of the genus '' Esox'' (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (''i.e.'' holarctic in distribution). They are known simply as a pike in Britain, Ireland, and most of Eastern Europe, Canada and the United States. Pike can grow to a relatively large size: the average length is about , with maximum recorded lengths of up to and published weights of . The IGFA currently recognizes a pike caught by Lothar Louis on Greffern Lake, Germany, on 16 October 1986, as the all-tackle world-record northern pike. Northern pike grow to larger sizes in Eurasia than in North America, and typically grow to larger sizes in coastal than inland regions of Eurasia. Etymology The northern pike gets its common name from its resemblance to the pole-weapon known as the pike (from the Middle English for 'pointed'). Various other unofficial trivial names are common pike, Lakes pike, great n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gambusia
''Gambusia'' is a large genus of viviparous fish in the family Poeciliidae (order Cyprinodontiformes). ''Gambusia'' contains over 40 species, most of which are principally found in freshwater habitats, though some species may also be found in brackish or saltwater habitats. The type species is the Cuban gambusia, ''G. punctata''. The greatest species richness is in Mexico, Texas, and the Greater Antilles, but species are also found elsewhere in the eastern and southern United States, the Bahamas, Central America, and Colombia. ''Gambusia'' species are often called topminnows, or simply gambusias; they are also known as mosquitofish, which, however, refers more specifically to two species, '' G. affinis'' and '' G. holbrooki'', which are often introduced into ponds to eat mosquito larvae. As a consequence, they have been introduced widely outside their native range, and frequently become invasive, threatening local species. They are only occasionally kept in aquariums, due to thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
