Venomous snake

Venomous snake

A venomous snake is a snake that uses modified saliva, venom, usually delivered through highly specialized teeth such as hollow fangs, for the purpose of prey immobilization and self-defense. In contrast, non-venomous species either constrict their prey, or simply overpower it with their jaws.

Venomous snakes include several families of snakes and do not form a single taxonomic group. This has been interpreted to mean that venom in snakes originated more than once as the result of convergent evolution. Evidence has recently been presented for the Toxicofera hypothesis however; if correct, venom was present (in small amounts) in the ancestor of all snakes (as well as several lizard families) as 'toxic saliva' and evolved to extremes in those snake families normally classified as venomous by parallel evolution. The Toxicofera hypothesis further implies that 'non-venomous' snake lineages have either lost the ability to produce venom (but may still have lingering venom pseudogenes) or actually do produce venom in small quantities, likely sufficient to assist in small prey capture, but not normally cause harm to humans if bitten.

Venomous snakes are often said to be poisonous, although this is not the correct term, as venoms and poisons are different. Poisons can be absorbed by the body, such as through the skin or digestive system, while venoms must first be introduced directly into tissues or the blood stream through mechanical means. It is, for example, therefore harmless to drink snake venom as long as there are no lacerations inside the mouth or digestive tract.Klauber LM. 1997. Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition. First published in 1956, 1972. University of California Press, Berkeley. ISBN 0-520-21056-5.]

Many other snakes, such as boas and pythons may not be venomous, but their bites should be attended to medically. Their teeth may be long and sharp, capable of inflicting lacerations, with bites often introducing mouth bacteria and shed teeth into the wound.

Families of venomous snakes

Over 600 species are known to be venomous -- about a quarter of all snake species. The following groups of snakes can be aggressive and inflict dangerous, even potentially lethal bites:

References

External links

* [http://www.fda.gov/Fdac/features/995_snakes.html For goodness snakes] Treating and Preventing Venomous Bites.
* [http://www.venomoussnakes.net Venomous Snakes] Pictures, videos and description of the most venomous snakes in the world.


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См. также в других словарях:

  • Venomous snake — Venomous Ven om*ous, a. [OE. venemous, venimous, F. venimeux, L. venenosus, fr. venenum poison. See {Venom}, and cf. {Venenose}.] 1. Full of venom; noxious to animal life; poisonous; as, the bite of a serpent may be venomous. [1913 Webster] 2.… …   The Collaborative International Dictionary of English

  • venomous snake — poisonous snake …   English contemporary dictionary

  • Snake wine — ( rượu rắn in Vietnamese) is an alcoholic beverage that includes a whole venomous snake in the bottle. It originated in Vietnam and can be found around Southeast Asia. The snakes, preferably venomous ones, are usually not preserved for their meat …   Wikipedia

  • Venomous — Ven om*ous, a. [OE. venemous, venimous, F. venimeux, L. venenosus, fr. venenum poison. See {Venom}, and cf. {Venenose}.] 1. Full of venom; noxious to animal life; poisonous; as, the bite of a serpent may be venomous. [1913 Webster] 2. (Zo[ o]l.)… …   The Collaborative International Dictionary of English

  • Snake — Ophidian redirects here. For the professional wrestler, see The Osirian Portal. This article is about the animal. For other uses, see Snake (disambiguation). Snakes Temporal range: Early Cretaceous – Recent, 112–0 Ma …   Wikipedia

  • Snake venom — Contents 1 Chemistry 1.1 Neurotoxins 1.2 Cytotoxins 2 …   Wikipedia

  • venomous — [[t]ve̱nəməs[/t]] 1) ADJ GRADED: usu ADJ n If you describe a person or their behaviour as venomous, you mean that they show great bitterness and anger towards someone. ...his terrifying and venomous Aunt Bridget... He heaped abuse on Waite and… …   English dictionary

  • venomous — adj. VERBS ▪ be ADVERB ▪ highly ▪ a highly venomous snake ▪ mildly ▪ a type of snail that is mildly venomous …   Collocations dictionary

  • snake — I n. 1) a poisonous, venomous snake 2) snakes bite, strike; coil; crawl; hibernate; hiss; molt, shed skin 3) (misc.) a snake in the grass ( a treacherous person ) II v. (colloq.) he snaked his way through the crowd * * * [sneɪk] coil crawl… …   Combinatory dictionary

  • venomous — venomously, adv. venomousness, venomness, n. /ven euh meuhs/, adj. 1. (of an animal) having a gland or glands for secreting venom; able to inflict a poisoned bite, sting, or wound: a venomous snake. 2. full of or containing venom; poisonous: a… …   Universalium


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