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Toxic Birds
Toxic birds are birds that use toxins to defend themselves from predators. Although no known bird actively injects or produces venom, toxic birds sequester poison from animals and plants they consume, especially poisonous insects. Species include the pitohui and ifrita birds from Papua New Guinea, the European quail, the spur-winged goose, hoopoes, the bronzewing pigeon, and the red warbler. The pitohui, the ifrita, and the rufous or little shrikethrush all sequester batrachotoxin in their skin and feathers. The African spur-winged goose is toxic to eat as it sequesters poison in its tissues, from the blister beetles that it feeds on. European quail are also known to be toxic and are able to cause coturnism at certain stages in their migrations. Initial research The first research done on toxic birds was published in 1992 by Dumbacher ''et al.'', which found traces of the neurotoxin homobatrachotoxin, a steroid alkaloid with the ability to polarize Na+ channels, in the feathers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homobatrachotoxin
Batrachotoxin (BTX) is an extremely potent cardiotoxic and neurotoxic steroidal alkaloid found in certain species of beetles, birds, and frogs. The name is from the Greek word . Structurally-related chemical compounds are often referred to collectively as batrachotoxins. In certain frogs, this alkaloid is present mostly on the skin. Such frogs are among those used for poisoning darts. Batrachotoxin binds to and irreversibly opens the sodium channels of nerve cells and prevents them from closing, resulting in paralysis and death. No antidote is known. History Batrachotoxin was discovered by Fritz Märki and Bernhard Witkop, at the National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland, U.S.A. Märki and Witkop separated the potent toxic alkaloids fraction from '' Phyllobates bicolor'' and determined its chemical properties in 1963. They isolated four major toxic steroidal alkaloids including batrachotoxin, homobatrachotoxin (iso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Venomous Animals
Numerous animal species naturally produce chemical toxins which are used to kill or incapacitate prey or as a defense against predators. Venomous animals actively deliver their toxins (called venom) into their target through a specially designed mechanism, such as a bite or sting, by using a ''venom apparatus'', such as fangs or a stinger, in a processes called envenomation. They are often distinguished from poisonous animals, which instead passively deliver their toxins (called poison) to their victims upon contact such as through inhalation, absorption through the skin, or after being ingested. The only difference between venomous animals and poisonous animals is how they deliver the toxins. This list deals exclusively with venomous animals. Venoms have adapted to serve a wide variety of purposes. Their intended effects can range from mild fleeting discomfort to paralysis and death, and they may be highly selective in which species they target, often making them harmless to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poisonous Amphibian
Poisonous amphibians are amphibians that produce toxins to defend themselves from Predation, predators. Amphibians Most toxic amphibians are poisonous to touch or eat. These amphibians usually sequester toxins from animals and plants on which they feed, commonly from poisonous insects or poisonous plants. Except certain salamandrid salamanders that can extrude sharp venom-tipped ribs, and two species of frogs with venom-tipped bone spurs on their skulls, amphibians are not known to actively inject venom. Toxic Frogs and Toads An example of poison ingestion derives from the poison dart frog. They get a deadly chemical called lipophilic alkaloid from consuming a poisonous food in the rainforest. They are immune to the poison and they secrete it through their skin as a defense mechanism against predators. This poison is so efficient, the native people of the South American Amazon rainforest use the frogs' toxins on their weapons to kill their prey, giving the frogs their nickname th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Poisonous Animals
The following is a list of poisonous animals, which are animals that passively deliver toxins (called poison) to their victims upon contact such as through inhalation, absorption through the skin, or after being ingested. They are often distinguished from venomous animals, which actively inject their toxins (called venom) into their victims through a venom apparatus such as fangs or a stinger. The only difference between poisonous animals and venomous animals is how they deliver the toxins. This list deals exclusively with poisonous animals. Poisonous animals This list is a partial list of animals that are poisonous to humans and other animals in that their flesh is toxic if consumed, or in some cases if they are touched: Frogs and toads Frogs * Corroboree frog * Mantella * Poison dart frog Toads Some of these toads are "milked" for their bufotoxins. *American toad * Asiatic toad *Cane toad * Colorado River toad *Common toad * European green toad * Fowler's toad Mammals *Sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrodotoxin
Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an Order (biology), order that includes Tetraodontidae, pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovered in these fish, it is found in several other animals (e.g., in blue-ringed octopus, blue-ringed octopuses, Taricha, rough-skinned newts, and Naticidae, moon snails). It is also produced by certain infectious or symbiotic bacteria like ''Pseudoalteromonas tetraodonis, Pseudoalteromonas'', ''Pseudomonas'', and ''Vibrio'' as well as other species found in symbiotic relationships with animals and plants. Although it produces thousands of intoxications annually and several deaths, it has shown efficacy for the treatment of cancer-related pain in phase II and III clinical trials. Tetrodotoxin is a sodium channel blocker. It inhibits the firing of action potentials in neurons by binding to the voltage-gated sodiu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pufferfish
Tetraodontidae is a family of marine and freshwater fish in the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowers, blowies, bubblefish, globefish, swellfish, toadfish, toadies, toadle, honey toads, sugar toads, and sea squab. They are morphologically similar to the closely related porcupinefish, which have large external spines (unlike the thinner, hidden spines of the Tetraodontidae, which are only visible when the fish have puffed up). The majority of pufferfish species are toxic, with some among the most poisonous vertebrates in the world. In certain species, the internal organs, such as the liver, and sometimes the skin, contain mucus tetrodotoxin, and are highly toxic to most animals when eaten; nevertheless, the meat of some species is considered a delicacy in Japan (as 河豚, pronounced ''fugu''), Korea (as 복, ''bok'', or 복어, ''bogeo''), and China (as 河豚, ''hétún'') w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Novo Synthesis
In chemistry, ''de novo'' synthesis () is the synthesis of complex molecules from simple molecules such as sugars or amino acids, as opposed to recycling after partial degradation. For example, nucleotides are not needed in the diet as they can be constructed from small precursor molecules such as formate and aspartate. Methionine, on the other hand, is needed in the diet because while it can be degraded to and then regenerated from homocysteine, it cannot be synthesized ''de novo''. Nucleotide ''De novo'' pathways of nucleotides do not use free bases: adenine (abbreviated as A), guanine (G), cytosine (C), thymine (T), or uracil (U). The purine ring is built up one atom or a few atoms at a time and attached to ribose throughout the process. Pyrimidine ring is synthesized as orotate and attached to ribose phosphate and later converted to common pyrimidine nucleotides. Cholesterol Cholesterol is an essential structural component of animal cell membranes. Cholesterol a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Selection
Sexual selection is a mechanism of evolution in which members of one sex mate choice, choose mates of the other sex to mating, mate with (intersexual selection), and compete with members of the same sex for access to members of the opposite sex (intrasexual selection). These two forms of selection mean that some individuals have greater reproductive success than others within a population, for example because they are more Animal sexual behaviour, attractive or prefer more attractive partners to produce offspring. Successful males benefit from frequent mating and monopolizing access to one or more fertile females. Females can maximise the return on the energy they invest in reproduction by selecting and mating with the best males. The concept was first articulated by Charles Darwin who wrote of a "second agency" other than natural selection, in which competition between mate candidates could lead to speciation. The theory was given a mathematical basis by Ronald Fisher in the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectoparasites
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson characterised parasites' way of feeding as "predators that eat prey in units of less than one". Parasites include single-celled protozoans such as the agents of malaria, sleeping sickness, and amoebic dysentery; animals such as hookworms, lice, mosquitoes, and vampire bats; fungi such as honey fungus and the agents of ringworm; and plants such as mistletoe, dodder, and the broomrapes. There are six major parasitic strategies of exploitation of animal hosts, namely parasitic castration, directly transmitted parasitism (by contact), trophicallytransmitted parasitism (by being eaten), vector-transmitted parasitism, parasitoidism, and micropredation. One major axis of classification concerns invasiveness: an endop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogeny
A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA. In other words, it is a branching diagram or a tree (graph theory), tree showing the evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical or genetic characteristics. In evolutionary biology, all life on Earth is theoretically part of a single phylogenetic tree, indicating common ancestry. Phylogenetics is the study of phylogenetic trees. The main challenge is to find a phylogenetic tree representing optimal evolutionary ancestry between a set of species or taxa. computational phylogenetics, Computational phylogenetics (also phylogeny inference) focuses on the algorithms involved in finding optimal phylogenetic tree in the phylogenetic landscape. Phylogene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choresine
''Choresine'' is a genus of beetles that belong to the family Melyridae. This genus of beetle is known to have high levels of batrachotoxins and is believed to be a possible toxin source for Pitohui and Blue-capped ifrit birds in New Guinea. Collections from Herowana in the Eastern Highlands Province that tested positive for batrachotoxins included the more abundant '' C. pulchra'', the less abundant '' C. semiopaca'' and the two infrequent '' C. rugiceps'' and '' C. sp. A'', the latter as yet unnamed. The locals advise against allowing these beetles to touch the eyes or sweaty face as a severe burning sensation can result. These species are all described as having metallic blue-violaceous elytra and a yellow and blackish pronotum. The name "nanisani" is used by villagers in Herowana equally for this group of insects, the numbing, tingling, burning sensation they cause and the Blue-capped ifrit. The hypothesis that ''Phyllobates'' frogs in South America obtain batrachotoxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
