Viperidae
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Viperidae | |
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Viperidae | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Suborder: | Serpentes |
Clade: | Colubroides |
Family: | Viperidae Oppel, 1811 |
Synonyms | |
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The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia,[2] Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs that permit deep penetration and injection of their venom.[3] Three subfamilies are currently recognized.[4] They are also known as viperids. The name "viper" is derived from the Latin word vipera, -ae, also meaning viper, possibly from vivus ("living") and parere ("to beget"), referring to the trait viviparity (giving live birth) common in vipers like most of the species of Boidae.[5]
Description
All viperids have a pair of relatively long
Almost all vipers have keeled scales, a stocky build with a short tail, and a triangle-shaped head distinct from the neck, owing to the location of the venom glands. The great majority have vertically elliptical, or slit-shaped, pupils that can open wide to cover most of the eye or close almost completely, which helps them to see in a wide range of light levels. Typically, vipers are nocturnal and ambush their prey.
Compared to many other snakes, vipers often appear rather sluggish. Most are ovoviviparous: the eggs are retained inside the mother's body, and the young emerge living. However, a few lay eggs in nests. Typically, the number of young in a clutch remains constant, but as the weight of the mother increases, larger eggs are produced, yielding larger young.
Geographic range
Viperid snakes are found in the Americas, Africa, Eurasia, and South Asia. In the Americas, they are native from south of
Venom
Viperid venoms typically contain an abundance of
Proteolytic venom is also dual-purpose: first, it is used for defense and to immobilize prey, as with neurotoxic venoms; second, many of the venom's enzymes have a digestive function, breaking down molecules such as lipids, nucleic acids, and proteins.[6] This is an important adaptation, as many vipers have inefficient digestive systems.[7]
Due to the nature of proteolytic venom, a viperid bite is often a very painful experience and should always be taken seriously, though it may not necessarily prove fatal. Even with prompt and proper treatment, a bite can still result in a permanent scar, and in the worst cases, the affected limb may even have to be amputated. A victim's fate is impossible to predict, as this depends on many factors, including the species and size of the snake involved, how much venom was injected (if any), and the size and condition of the patient before being bitten. Viper bite victims may also be allergic to the venom or the antivenom.
Behavior
These snakes can decide how much venom to inject depending on the circumstances. The most important determinant of venom expenditure is generally the size of the snake; larger specimens can deliver much more venom. The species is also important, since some are likely to inject more venom than others, may have more venom available, strike more accurately, or deliver a number of bites in a short time. In predatory bites, factors that influence the amount of venom injected include the size of the prey, the species of prey, and whether the prey item is held or released. The need to label prey for chemosensory relocation after a bite and release may also play a role. In defensive bites, the amount of venom injected may be determined by the size or species of the predator (or antagonist), as well as the assessed level of threat, although larger assailants and higher threat levels may not necessarily lead to larger amounts of venom being injected.[8]
Prey tracking
Hemotoxic venom takes more time than neurotoxic venom to immobilize prey, so viperid snakes need to track down prey animals after they have been bitten,[8] in a process known as "prey relocalization". Vipers are able to do this via certain proteins contained in their venom. This important adaptation allowed rattlesnakes to evolve the strike-and-release bite mechanism, which provided a huge benefit to snakes by minimizing contact with potentially dangerous prey animals.[9] This adaptation, then, requires the snake to track down the bitten animal to eat it, in an environment full of other animals of the same species. Western diamondback rattlesnakes respond more actively to mouse carcasses that have been injected with crude rattlesnake venom. When the various components of the venom were separated out, the snakes responded to mice injected with two kinds of disintegrins, which are responsible for allowing the snakes to track down their prey.[9]
Subfamilies
Subfamily[4] | Taxon author[4] | Genera[4] | Common name | Geographic range[1] |
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Azemiopinae
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Liem, Marx & Rabb, 1971 | 1 | Fea's vipers | Myanmar, southeastern Tibet across South China (Fujian, Guangxi, Jiangxi, Guizhou, Sichuan, Yunnan, Zhejiang) to Northern Vietnam |
Crotalinae
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Oppel, 1811 | 22 | Pit vipers | In the southern South America
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Viperinae | Oppel, 1811 | 13 | True or pitless vipers | Europe, Asia, and Africa |
Type genus = Vipera Laurenti, 1768[1]
Sensory organs
Heat-sensing pits
Taxonomy
Whether family Viperidae is attributed to Oppel (1811), as opposed to Laurenti (1768) or Gray (1825), is subject to some interpretation. The consensus among leading experts, though, is that Laurenti used viperae as the plural of vipera (Latin for "viper", "adder", or "snake") and did not intend for it to indicate a family group taxon. Rather, it is attributed to Oppel, based on his Viperini as a distinct family group name, despite the fact that Gray was the first to use the form Viperinae.[1]
See also
- List of snakes, overview of all snake families and genera
- Snakebite
References
- ^ ISBN 1-893777-01-4(volume).
- ^ Fender-Barnett, Arli (27 May 2019). "Are Australian snakes really the most dangerous in the world?". CSIRO. Archived from the original on 9 December 2023.
Yes, we have some scary snakes in Australia but none are close to what's happening in tropical parts of Asia, Africa and South America – they have a group of snakes called Vipers (which we don't have, phew!).
- ^ a b "Viperids". Snakesuntamed.webr.ly. Archived from the original on 8 January 2015. Retrieved 8 January 2015.
- ^ a b c d "Viperidae". Integrated Taxonomic Information System. Retrieved 10 August 2006.
- ISBN 0-7137-1704-1.
- ^ Slowinski, Joe (2000). "Striking Beauties: Venomous Snakes". California Wild. 53 (2). Archived from the original on 13 October 2004.
- ^ Smith, SA (2004). "Did Someone Say... SSSSnakes?". Maryland Dept. of Natural Resources. Archived from the original on 21 July 2006. Retrieved 2 December 2006.
- ^ ISBN 0-9720154-0-X.
- ^ PMID 23452837.
- ^ PMID 13377311.
- .
- .
- PMID 20228791.
Further reading
- Gray JE. 1825. A synopsis of the genera of reptiles and Amphibia, with a description of some new species. Annals of Philosophy, new ser., 10: 193–217.
- Laurenti JN. 1768. Specimen Medicum, Exhibens Synopsin Reptilium Emendatam cum Experimentis circa Venena et antidota reptilium Austriacorum. J.T. de Trattnern, Wien.
- Oppel M. 1811. Mémoire sur la classification des reptiles. Ordre II. Reptiles à écailles. Section II. Ophidiens. Annales du Musée National d'Histoire Naturelle, Paris 16: 254–295, 376–393.
External links
- Viperidae at the Reptarium.cz Reptile Database. Accessed 3 November 2008.
- Ripley, George; Dana, Charles A., eds. (1879). The American Cyclopædia.
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- . . 1914.
- Pit vipers