Venom 32771 223650746 2008-07-05T02:22:24Z Insanity Incarnate 3763104 Reverted edits by [[Special:Contributions/71.106.106.119|71.106.106.119]] to last version by AlexiusHoratius (using [[WP:HG|Huggle]]) :''This article is about the class of [[biotoxin]]s. For other uses, see [[Venom (disambiguation)]] and [[Venomous (disambiguation)]].'' {{toxicology}} {{Citations missing|date=February 2008}} '''Venom''' is any of a variety of [[toxin]]s used by certain types of [[animal]]s, for the purpose of defense and [[hunting]]. Generally, venom is delivered (injected) by such means as a bite or a sting, while a [[poison]] is absorbed by ingestion or through the skin. [[Image:Waspstinger1658-2.jpg|200px|left|thumb|[[Wasp]] [[stinger (organ)|sting]], with droplet of venom]] The animals most widely known to use venom are [[snake]]s, some species of which inject venom into their prey through hollow [[tooth|fang]]s; [[spider (animal)|spiders]] and [[centipede]]s, which also inject venom through fangs; [[scorpion]]s and stinging [[insect]]s, which inject venom with a sting (which, in insects such as [[bees]] and [[wasps]], is a modified egg-laying device – the [[ovipositor]]). Many [[caterpillar]]s have defensive venom glands associated with specialized bristles on the body, known as [[urtication|urticating hairs]], and can be lethal to humans (e.g., that of the ''[[Lonomia]]'' moth). Venom is also found in a few reptiles besides snakes, such as the [[gila monster]] and [[Mexican beaded lizard]]. Other insects, such as [[Hemiptera|true bug]]s [http://ufbir.ifas.ufl.edu/Chap23.htm] and many [[ants]], also produce venom. Venom can also be found in some [[fish]], such as the cartilaginous fishes – [[stingrays]], [[shark]]s, and [[chimaera]]s – and the [[teleost]] fishes including [[monognathus]] eels, [[catfishes]], [[stonefish]]es and waspfishes, [[scorpionfish]]es and [[lionfish]]es, gurnard perches, [[rabbitfishes]], [[surgeonfish]]es, [[Scatophagidae|scats]], [[stargazers]], [[weever]]s, [[carangid]]s, [[saber-toothed blenny]], and [[toadfish]]. In fact, recent studies have shown that there are more venomous ray-finned fishes than all other venomous [[vertebrate]]s combined. There are many other venomous invertebrates, including [[jellyfish]] and [[cone snails]]. The [[box jellyfish]] is widely considered the most venomous creature in the world.[http://en.wikipedia.org/wiki/Box_jellyfish#treatmentofstings] Some mammals are also venomous, including [[solenodon]]s, [[shrews]], the [[slow loris]], and the male [[platypus]]. Because they are tasked to defend their hives and food stores, bees synthesize and employ an acidic venom ([[apitoxin]]) to cause pain in those that they sting, whereas wasps use a chemically different venom designed to paralyze prey, so it can be stored alive in the food chambers of their young. The use of venom is much more widespread than just these examples, of course. ==Venomous vs. poisonous== There is a difference between organisms that are "venomous" and those that are "[[poisonous]]", two commonly confused terms applied to [[plant]] and [[animal]] life. ''Venomous'', as stated above, refers to animals that deliver (often, [[Wiktionary:inject|inject]]) venom into their [[prey]] when hunting or as a defense mechanism. ''Poisonous'', on the other hand, describes plants or animals that are harmful when consumed or touched.<ref>''E.g.'', Kenneth G. Wilson, ''The Columbia Guide to Standard American English''. 1993.</ref> A poison tends to be distributed over a large part of the body of the organism producing it, while venom is typically produced in organs specialized for the purpose.<ref>[http://www.fathom.com/course/10701017/session1.html Zoltan Takacs, The Biology of Venomous Animals. Session 1. Columbia University, 2001.]</ref> One species of bird, the [[Hooded Pitohui|hooded pitohui]], although not venomous, is poisonous, secreting a [[neurotoxin]] onto its skin and feathers. The [[slow loris]], a primate, blurs the boundary between poisonous and venomous; it has poison-secreting patches on the inside of its elbows which it is believed to smear on its young to prevent them from being eaten. However, it will also lick these patches, giving it a venomous bite. ==Snake venom== {{main|Snake venom}} Snake venom is produced by glands below the eye and delivered to the victim through tubular or channeled fangs. Snake poisons contain a variety of [[peptide]] toxins. Snakes use their venom principally for hunting, though the threat of being bitten serves also as a defense. Snake bites cause a variety of symptoms including pain, swelling, tissue damage, low blood pressure, convulsions, and hemorrhaging (varying by species of snake). Doctors treat victims of a venomous bite with [[antivenin]], which is created by dosing an animal such as a [[sheep]], [[horse]], [[goat]], or [[rabbit]] with a small amount of the targeted venom. The immune system of the subject animal responds to the dose, producing [[antibodies]] to the venom's active molecule; the antibodies can then be harvested from the animal's blood and applied to treat envenomation in others. This treatment can be used effectively only a limited number of times for a given person, however, as that person will ultimately develop antibodies to neutralize the foreign animal antibodies injected into him (anti-antibody antibodies). Even if that person does not suffer a serious allergic reaction to the antivenom, his own immune system can destroy the antivenin before the antivenin can destroy the venom. Though most people never require even one treatment of antivenin in their lifetime, let alone several, people who work with snakes or other venomous animals may. Fortunately, these people often develop antibodies of their own against the venom of whatever animals they handle, and thereby are protected without the assistance of exogenous antibodies. [[Aristolochia rugosa]] and [[Aristolochia trilobata]], or "Dutchman's Pipe," are recorded in a list of plants used worldwide and in the West Indies, South and Central America against snakebites and scorpion stings. [[Aristolochic acid]] inhibits inflammation induced by immune complexes, and nonimmunological agents (carrageenan or croton oil).{{Fact|date=January 2008}} Aristolochic acid inhibits the activity of snake venom phospholipase (PLA2) by forming a 1:1 complex with the enzyme. Since phospholipase enzymes play a significant part in the cascade leading to the inflammatory and pain response, their inhibition could lead to relief of problems from scorpion envenomation. ==See also== * [[Toxin]] * [[Poison]] * [[Toxinology]] * [[Schmidt Sting Pain Index]] * [[Venomous mammals]] * [[Venomous fish]] * [[Big Four (Indian snakes)]] * [[Envenomation]] * [[:Category:Venomous animals|Venomous animals]] (category) ==Notes== {{reflist}} ==Bibliography== * Leo Smith and Ward C. Wheeler. 2006. Venom evolution widespread in fishes: A phylogenetic road map for the bioprospecting of piscine venoms. Journal of Heredity 97(3): 206-217. * Lans C, Harper T, Georges K, Bridgewater E. 2001. Medicinal and ethnoveterinary remedies of hunters in Trinidad. BMC Complement Altern Med. 2001;1:10. Epub 2001 Nov 30. http://www.biomedcentral.com/1472-6882/1/10 {{Poisoning and toxicity}} [[Category:Toxins]] [[ar:فينوم]] [[eo:Ĉasveneno]] [[fr:Venin]] [[id:Bisa]] [[he:ארס]] [[pl:Jad]] [[pt:Peçonha]]