Jump to content

Snake: Difference between revisions

Edit links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
m BOT - Reverted edits by 76.69.127.24 {possible vandalism} to last version by VoABot II.
Qqstar (talk | contribs)
9 edits
m mirno
Line 1: Line 1:
fuck you bicth thats what a snake says
{{otheruses}}
{{redirect|Ophidian|the musician|Ophidian (musician)}}
{{Taxobox
| color = pink
| name = Snakes
| fossil_range = [[Cretaceous]] - [[Holocene|Recent]]
| image = Antaresia maculosa.jpg
| image_width = 250px
| image_caption = Spotted Python<br/>''[[Antaresia maculosa]]''
| regnum = [[Animal]]ia
| phylum = [[Chordata]]
| subphylum = [[Vertebrata]]
| classis = [[Sauropsid]]a
| subclassis = [[Diapsida]]
| infraclassis = [[Lepidosauromorpha]]
| superordo = [[Lepidosauria]]
| ordo = [[Squamata]]
|<!-- unranked_ordo = [[Scleroglossa]] this does not work -->
| subordo = '''Serpentes'''
| subordo_authority = [[Carolus Linnaeus|Linnaeus]], [[1758]]
| subdivision_ranks = [[Infraorder]]s and [[Family (biology)|Families]]
| subdivision =
* [[Alethinophidia]] - <small>[[Franz Nopcsa von Felső-Szilvás|Nopcsa]], [[1923]]</small>
** [[Acrochordidae]]- <small>[[Charles Lucien Bonaparte|Bonaparte]], [[1831]]</small>
** [[Aniliidae]] - <small>[[Leonhard Hess Stejneger|Stejneger]], [[1907]]</small>
** [[Anomochilidae]] - <small>Cundall, Wallach & Rossman, 1993</small>
** [[Atractaspididae]] - <small>[[Albert C. L. G. Günther|Günther]], [[1858]]</small>
** [[Boidae]] - <small>[[John Edward Gray|Gray]], [[1825]]</small>
** [[Bolyeriidae]] - <small>Hoffstetter, [[1946]]</small>
** [[Colubridae]] - <small>[[Nicolaus Michael Oppel|Oppel]], [[1811]]</small>
** [[Cylindrophiidae]] - <small>[[Leopold Fitzinger|Fitzinger]], [[1843]]</small>
** [[Elapidae]] - <small>[[Friedrich Boie|F. Boie]], [[1827]]</small>
** [[Loxocemidae]] - <small>[[Edward Drinker Cope|Cope]], [[1861]]</small>
** [[Pythonidae]] - <small>[[Leopold Fitzinger|Fitzinger]], [[1826]]</small>
** [[Tropidophiidae]] - <small>[[Leo Brongersma|Brongersma]], [[1951]]</small>
** [[Uropeltidae]] - <small>[[Johannes Peter Müller|Müller]], 1832</small>
** [[Viperidae]] - <small>[[Nicolaus Michael Oppel|Oppel]], [[1811]]</small>
** [[Xenopeltidae]] - <small>[[Charles Lucien Bonaparte|Bonaparte]], [[1845]]</small>
* [[Scolecophidia]] - <small>[[Edward Drinker Cope|Cope]], [[1864]]</small>
** [[Anomalepididae]] - <small>[[Edward Harrison Taylor|Taylor]], [[1939]]</small>
** [[Leptotyphlopidae]] - <small>[[Leonhard Hess Stejneger|Stejneger]], [[1892]]</small>
** [[Typhlopidae]] - <small>[[Blasius Merrem|Merrem]], [[1820]]</small>
}}
A '''snake''' is an elongate [[reptile]] of the suborder ''Serpentes''. Like all reptiles, snakes are [[ectothermic]] and covered in [[Scale (zoology)|scales]]. All snakes are [[carnivore|carnivorous]] and can be distinguished from [[limbless vertebrates|legless lizards]] by their lack of eyelids, limbs, external ears, and vestiges of forelimbs. The 2,900 species of snakes spread across every continent except Antarctica ranging in size from the tiny, 10 cm long [[Leptotyphlops bilineatus|thread snake]] to [[pythonidae|python]]s and [[anaconda]]s over 7 meters long. In order to accommodate snakes' narrow bodies, paired organs (such as kidneys) appear one in front of the other instead of side by side.

While venomous snakes comprise a minority of the species of snakes and are typically small innocuous creatures, some possess potent venom capable of causing painful injury or death to humans. However, venom in snakes is primarily for killing and subduing prey rather than for self-defense.

Snakes may have evolved from a lizard which adapted to burrowing during the [[Cretaceous]] period (''c'' 150 [[Mega-annum|Ma]]), though some scientists have postulated an aquatic origin. The diversity of modern snakes appeared during the [[Paleocene]] period (''c'' 66 to 56 Ma).

A literary word for snake is '''serpent''' (a [[Middle English]] word which comes from [[Old French]], and ultimately from ''*serp-'', "to creep"<ref name="serpent">{{cite web | work=Merriam-Webster Online Dictionary | title=Definition of serpent - Merriam-Webster Online Dictionary|url=http://www.merriam-webster.com/dictionary/serpent| accessdate=12 October|accessyear=2006}}</ref>). In modern usage, the term serpent usually refers to a mythic or [[serpent (symbolism)|symbolic snake]]. In [[Christianity]], the serpent is often identified with the devil, as in the Biblical account of [[Adam and Eve]].

==Taxonomy==
Snakes are categorized in the order ''[[Squamata]]'' within the entire [[Class (biology)|suborder]] ''Serpentes'' in [[Linnean taxonomy]].<ref name="ITIS">{{ITIS|ID=174118|taxon=Serpentes|year=2007|date=20 August}}</ref> There are two [[infraorder]]s of ''Serpentes'': [[Alethinophidia]] and [[Scolecophidia]].<ref name="ITIS"/> This separation is based primarily on [[comparative anatomy|morphological]] characteristics between family groups and [[mitochondrial DNA]].

As with most taxonomic classifications, there are different interpretations of the evolutionary relationships. These include moving of families to different infraorders, merging or splitting of the infraorders and merging and splitting of the families. For instance, many sources classify [[Boidae]] and [[Pythonidae]] as the same family, or keep others, such as [[Elapidae]] and [[Hydrophiidae]], separate for practical reasons despite their extremely close relation.

{| class="wikitable"
|-
|colspan="100%" align="center" {{bgcolor-blue}}|'''[[Alethinophidia]]''' 15 families
|-
!Family!!Common Names!!Example Species!!Example Photo
|-
|[[Acrochordidae]]<br><small>[[Charles Lucien Bonaparte|Bonaparte]], 1831</small><ref name="Cogger91_23"/>||file snakes||[[Acrochordus granulatus|Marine File Snake]] (''Acrochordus granulatus'')||[[Image:Wart_snake_1.jpg|100px]]
|-
|[[Aniliidae]]<br><small>[[Leonhard Hess Stejneger|Stejneger]], 1907</small><ref>{{ITIS|ID=209611|taxon=Aniliidae|year=2007|date=12 December}}</ref> ||coral pipe snakes||[[Anilius scytale|Burrowing False Coral]] (''Anilius scytale'')||
|-
|[[Anomochilidae]]<br><small>Cundall, Wallach and [[Douglas Athon Rossman|Rossman]], 1993</small>.<ref>{{ITIS|ID=563894|taxon=Anomochilidae|year=2007|date=13 December}}</ref>||dwarf pipe snakes||[[Leonard's Pipe Snake]], (''Anomochilus leonardi'')||
|-
|[[Atractaspididae]]<br><small>[[Albert C. L. G. Günther|Günther]], 1858</small><ref>{{ITIS|ID=563895|taxon=Atractaspididae|year=2007|date=13 December}}</ref>
||mole vipers||[[Stiletto Snake]] (''Atractaspis bibroni'') ||
|-
|[[Boidae]]<br><small>[[John Edward Gray|Gray]], 1825</small><ref name="Cogger91_23">Cogger(1991), p.23</ref>||boas||[[Amazon tree boa]] (''Corallus hortulanus'')||[[Image:Corallushortulanus.GIF|100px]]
|-
|[[Bolyeriidae]]<br><small>[[Robert Hoffstetter|Hoffstetter]], 1946</small>||Round Island boas||[[Round Island Burrowing Boa]] (''Bolyeria multocarinata'')||
|-
|[[Colubridae]]<br><small>[[Nicolaus Michael Oppel|Oppel]], 1811</small><ref name="Cogger91_23"/>||colubrids||[[Grass Snake]] (''Natrix natrix'')||[[Image:Natrix natrix (Marek Szczepanek).jpg|100px]]
|-
|[[Cylindrophiidae]]<br><small>[[Leopold Fitzinger|Fitzinger]], 1843</small>||Asian pipe snakes||[[Red-tailed Pipe Snake]] (''Cylindrophis ruffus'')|| [[Image:Cylindrophis rufus.jpg|100px]]
|-
|[[Elapidae]]<br><small>[[Friedrich Boie|Boie]], 1827</small><ref name="Cogger91_23"/>||cobras, coral snakes, mambas, kraits, sea snakes, sea kraits, Australian elapids||[[King Cobra]] (''Ophiophagus hannah'')||[[Image:KINGCOBRA.jpg|100px]]
|-
|[[Loxocemidae]]<br><small>[[Edward Drinker Cope|Cope]], 1861</small>||Mexican burrowing snakes||[[Mexican burrowing snake]] (''Loxocemus bicolor'')||[[Image:Loxocemus_bicolor.jpg|100px]]
|-
|[[Pythonidae]]<br><small>[[Leopold Fitzinger|Fitzinger]], 1826</small>||pythons||[[Ball python]]/[[Royal python]] (''Python regius'')||[[Image:Python_Regius_Pastel.jpg|100px]]
|-
|[[Tropidophiidae]]<br><small>[[L.D. Brongersma|Brongersma]], 1951</small>||dwarf boas||[[Northern Eyelash Boa]] (''Trachyboa boulengeri'') ||
|-
|[[Uropeltidae]]<br><small>[[Johannes Peter Müller|Müller]], 1832</small>||shield-tailed snakes, short-tailed snakes||[[Uropeltis ocellatus|Ocellated Shield-tail]] (''Uropeltis ocellatus'')||
|-
|[[Viperidae]]<br><small>[[Nicolaus Michael Oppel|Oppel]], 1811</small><ref name="Cogger91_23"/>||vipers, pitvipers, rattlesnakes||[[Vipera aspis|European asp]] (''Vipera aspis'')||[[Image:Vipera-aspis-aspis-1.jpg|100px]]
|-
|[[Xenopeltidae]]<br><small>[[Charles Lucien Bonaparte|Bonaparte]], 1845</small>||sunbeam snakes||[[Xenopeltis unicolor|Sunbeam snake]] (''Xenopeltis unicolor'')||
|-
|colspan="100%" align="center" {{bgcolor-blue}}|'''[[Scolecophidia]]''' 3 families
|-
!Family!!Common Names!!Example Species!!Example Photo
|-
|[[Anomalepidae]]<br><small>[[Edward Harrison Taylor|Taylor]], 1939</small><ref name="Cogger91_23"/>||dawn blind snakes||[[Dawn Blind Snake]] (''Liotyphlops beui'')||<!-- Commented out because image was deleted: [[Image:Liotyphl.jpg|100px|{{deletable image-caption|1=Sunday, 16 December 2007}}]] -->
|-
|[[Leptotyphlopidae]]<br><small>[[Leonhard Hess Stejneger|Stejneger]], 1892</small><ref name="Cogger91_23"/>||slender blind snakes||[[Texas Blind Snake]] (''Leptotyphlops dulcis'')||[[Image:Leptotyphlops_dulcis.jpg|100px]]
|-
|[[Typhlopidae]]<br><small>[[Blasius Merrem|Merrem]], 1820</small><ref>{{ITIS|ID=174338|taxon=Typhlopidae|year=2007|date=13 December}}</ref>||blind snakes||[[Black Blind Snake]] (''Typhlops reticulatus'')||<!-- Commented out because image was deleted: [[Image:Typhlops.jpg|100px|{{deletable image-caption|1=Sunday, 16 December 2007}}]] -->
|-
|}

==Evolution==
[[Phylogenetics|Phylogeny]] of snakes is poorly known because snake [[skeleton]]s are typically small and fragile, making [[fossilization]] uncommon. However 150 million year old specimens readily definable as snakes with lizard-like skeletal structures have been uncovered in [[South America]] and [[Africa]].<ref name="Mehrtens87_11">Mehrtens (1987) p. 11</ref> It has been agreed, on the basis of [[Comparative anatomy|morphology]], that snakes descended from [[lizard|lizards]].<ref name="Sanchez">
{{citation
| last = Sanchez
| first = Alejandro
| title = Diapsids III: Snakes
| work= Father Sanchez's Web Site of West Indian Natural History
| url = http://www.kingsnake.com/westindian/metazoa12.html
| accessdate = November 26, 2007
}}
</ref><ref name="Mehrtens87_11"/> Molecular evidence reinforces this; it is hypothesized that snakes share a common venomous ancestor with several lizard families, forming the [[Toxicofera]] clade.

Fossil evidence suggests that snakes may have evolved from burrowing lizards, such as [[varanid]]s or a similar group during the [[Cretaceous|Cretaceous Period]].<ref name="EB">{{Citation
| last =Mc Dowell
| first =Samuel
| title =The evolution of the tongue of snakes and its bearing on snake origins
| journal =Evolutionary Biology
| year =1972
| volume=6
| pages = 191-273
}}
</ref> An early fossil snake, ''[[Najash rionegrina]]'', was a two-legged burrowing animal with a [[sacrum]], and was fully [[Terrestrial animal|terrestrial]].<ref>
{{cite journal
| last = Apesteguía
| first = Sebastián
| coauthors = Hussam Zaher
| year = 2006
| month = April
| title = A Cretaceous terrestrial snake with robust hindlimbs and a sacrum
| journal = Nature
| volume = 440
| issue = 7087
| pages = 1037&ndash;1040
| id = {{doi|10.1038/nature04413}}
| url = http://www.nature.com/nature/journal/v440/n7087/edsumm/e060420-11.html | accessdate = 2007-11-29 }}
</ref> One extant analog of these putative ancestors is the earless monitor ''[[Lanthanotidae|Lanthanotus]]'' of [[Borneo]], although it also is semi-[[Aquatic animal|aquatic]].<ref name="M2">{{Citation
| last =Mertens
| first =Robert
| title =Lanthanotus: an important lizard in evolution
| journal =Sarawak Museum Journal
| year =1961
| volume=10
| pages = 320-322
}}</ref> As these ancestors became more [[wiktionary:subterranean|subterranean]], they lost their limbs and their bodies became more streamlined for burrowing.<ref name="M2"/> According to this hypothesis, features such as the [[Transparency (optics)|transparent]], fused eyelids ([[brille]]) and loss of external ears evolved to combat subterranean conditions such as scratched corneas and dirt in the ears with snakes re-emerged onto the surface of the earth much as they are today.<ref name="M2"/><ref name="EB"/> Other primitive snakes are known to have possessed hindlimbs but lacked a direct connection of the pelvic bones to the vertebrae, including ''[[Haasiophis]]'', ''[[Pachyrhachis]]'' and ''Eupodophis'') which are slightly older than ''[[Najash]]''.<ref name="legs">
{{cite web
| title = New Fossil Snake With Legs
| work = UNEP WCMC Database
| publisher =American Association For The Advancement Of Science
| location = [[ Washington, D.C.]]
| url =http://www.wildlifenews.co.uk/articles2000/march/march2500a.htm
| accessdate =11/29/2007 }}
</ref>

[[Image:Micrurus tener.jpg|200px|thumb|left|[[Texas Coral Snake]] ''Micrurus tener'']] Primitive groups among the modern snakes, [[Pythonidae|python]]s and [[boa]]s, have vestigial hind limbs: tiny, clawed digits known as [[anal spur]]s which are used to grasp during mating.<ref name="legs"/><ref name="Mehrtens87_11"/> [[Leptotyphlopidae]] and [[Typhlopidae]] are other examples where remnants of the pelvic girdle are still present, sometimes appearing as horny projections when visible. The frontal limbs in all snakes are non-existent because of the evolution of the [[Homeobox#Hox genes|Hox gene]]s in this area. The axial skeleton of the snakes' common ancestor had like most other tetrapods the familiar regional specializations consisting of cervical (neck), thoracic (chest), lumbar (lower back), sacral (pelvic) and caudal (tail) vertebrae. The Hox gene expression in the axial skeleton responsible for the development of the thorax became dominant early in snake evolution and as a result, the vertebrae anterior to the hindlimb buds (when present) all have the same thoracic-like identity (except from the [[Atlas (anatomy)|atlas]], [[Axis (anatomy)|axis]] and 1-3 neck vertebrae), making most of the snake's skeleton being composed of an extremely extended thorax. Ribs are found exclusively on the thoracic vertebrae. The neck, lumbar and pelvic vertebrae are very reduced in number (only 2-10 lumbar and pelvic vertebrae are still present), while only a short tail remains of the caudal vertebrae, although the tail is still long enough to be of good use in many species, and is modified in some aquatic and tree dwelling species.

An alternative hypothesis, based on [[Morphology (biology)|morphology]], suggests that the ancestors of snakes were related to [[mosasaur]]s &mdash; extinct [[aquatic animal|aquatic]] reptiles from the [[Cretaceous]] &mdash; which in turn are thought to have derived from [[monitor lizard|varanid lizard]]s.<ref name="Sanchez"/> Under this hypothesis, the fused, transparent eyelids of snakes are thought to have evolved to combat marine conditions (corneal water loss through osmosis), while the external ears were lost through disuse in an aquatic environment, ultimately leading to an animal similar in appearance to [[sea snake]]s of today. In the Late [[Cretaceous]], snakes re-colonized the land much like they are today. Fossil snake remains are known from early Late Cretaceous marine sediments, which is consistent with this hypothesis, particularly as they are older than the terrestrial ''Najash rionegrina''. Similar skull structure; reduced/absent limbs; and other anatomical features found in both mosasaurs and snakes lead to a positive [[Cladistics|cladistic]]al correlation, although some of these features are shared with [[varanid]]s. In recent years, genetic studies have indicated that snakes are not as closely related to monitor lizards as it was once believed, and therefore not to mosasaurs, the proposed ancestor in the aquatic scenario of their evolution. However, there is more evidence linking mosasaurs to snakes than to varanids. Fragmentary remains that have been found from the [[Jurassic]] and Early Cretaceous indicate deeper fossil records for these groups, which may eventually refute either hypothesis.

The great diversity of modern snakes appeared in the [[Paleocene]], correlating with the [[adaptive radiation]] of mammals following the extinction of the [[dinosaur]]s. There are over 2,900 species of snakes ranging as far northward as the [[Arctic Circle]] in [[Scandinavia]] and southward through [[Australia]] and [[Tasmania]].<ref name="Sanchez"/> Snakes can be found on every continent with the exception of [[Antarctica]] dwelling in the sea and as high as 16,000 feet (4900m)in the [[Himalayan Mountains]] of [[Asia]].<ref name="Sanchez"/><ref name="Conant91_143">Conant (1991), p.143</ref> There are numerous islands from which snakes are conspicuously absent such as [[Ireland]], [[Iceland]], and [[New Zealand]].<ref name="Conant91_143"/>

==Digestion and diet==
[[Image:Snake eating mouse.jpg|thumb|right|250px|Snake eating a rat]] All snakes are strictly [[carnivore|carnivorous]], eating small animals including lizards, other snakes, small mammals, birds, [[egg (biology)|eggs]], fish, snails or insects.<ref name="Sanchez"/><ref name="Bebler79_581">Bebler (1979) p.581</ref><ref name="Mehrtens_1987_81"/> Because snakes cannot bite or tear their food to pieces, prey must be swallowed whole. The body size of a snake has a major influence on its eating habits. Smaller snakes eat smaller prey. Juvenile pythons might start out feeding on lizards or mice and graduate to small deer or antelope as an adult, for example.

The snake's jaw is the most unique jaw in the animal kingdom. Contrary to popular belief, snakes do ''NOT'' dislocate their jaws. They disarticulate their jaws. Basically the jaw acts like a hinge opening down up to 180° then the chin (which is not connected in the middle) spreads wide.

While the majority of snakes eat a variety of prey animals, there is some specialization by some species. [[King cobra]]s and the Australian [[Bandy-bandy]] consume other snakes. ''Pareas iwesakii'' and other [[snail]]-eating [[Colubrid]]s of subfamily [[Pareatinae]] have more teeth on the right side of their mouths than on the left, as the shells of their prey usually spiral clockwise<ref>Hoso, M., T. Takahiro & M. Hori. (2007) "Right-handed snakes: convergent evolution of asymmetry for functional specialization." ''Biol. Lett.'' '''3''': 169-72.</ref><ref>Mehrtens (1987), p.184</ref>

Some snakes have a venomous bite, which they use to kill their prey before eating it.<ref>Freiberg (1984), pp.125-127</ref><ref name="Bebler79_581"/> Other snakes kill their prey by [[constriction]].<ref name="Bebler79_581"/> Still others swallow their prey whole and alive.<ref name="Bebler79_581"/><ref name="Mehrtens_1987_81"/>
[[Image:Eierschlange frisst Zwergwachtelei.jpg|left|thumb|180px|[[Dasypeltis|African Egg-eating Snake]]]]
Snakes do not chew their food and have a very flexible [[mandible|lower jaw]], the two halves of which are not rigidly attached, and numerous other joints in their skull (see [[snake skull]]), allowing them to open their mouths wide enough to swallow their prey whole, even if it is larger in diameter than the snake itself.<ref name="Bebler79_581"/> The [[Dasypeltis|African Egg-eating Snake]] has flexible jaws adapted for eating eggs much larger than the diameter of its head.<ref name="Mehrtens_1987_81"/> This snake has no [[teeth]], but does have bony protrusions on the inside edge of its [[Vertebral column|spine]] which are used to aid in breaking the shells of the eggs it eats.<ref name="Mehrtens_1987_81">Mehrtens (1987), p.81</ref>

After eating, snakes become torpid while the process of [[digestion]] takes place.<ref name="Rosenfeld_11"> Rosenfeld(1989), p.11</ref> Digestion is an intense activity, especially after the consumption of very large prey. In species that feed only sporadically, the entire intestine enters a reduced state between meals to conserve energy, and the digestive system is 'up-regulated' to full capacity within 48 hours of prey consumption. Being [[ectothermic]] or cold blooded, the surrounding temperature plays a large role in a snake's digestion. 30 degrees celsius is the ideal temperature for snakes to digest their food. So much metabolic energy is involved in digestion that in ''Crotalus durissus'', the Mexican rattlesnake, an increase of body temperature to as much as 1.2 degrees [[Celsius]] above the surrounding environment has been observed.<ref> {{cite web
| coauthors =Glenn J. Tattersall1, William K. Milsom, Augusto S. Abe, Simone P. Brito, Denis V. Andrade
| year = 2004
| url =http://jeb.biologists.org/cgi/content/abstract/207/4/579
| title =The thermogenesis of digestion in rattlesnakes
| work =Journal of Experimental Biology 207
| pages =579-585
| publisher =The Company of Biologists
| accessdate =2006-05-26
| accessyear =2006
}}</ref> Because of this, a snake disturbed after having eaten recently will often regurgitate its prey in order to be able to escape the perceived threat. However, when undisturbed, the digestive process is highly efficient, dissolving and absorbing everything but hair and claws, which are excreted along with [[uric acid]] waste.

==Skin==
{{main|Snake scales}}
[[Image:Nerodia sipedon shedding.JPG|thumb|240px|left|A snake shedding its skin]]
[[Image:Ptyas gab fbi.png|thumb|400px|right|A line diagram from G.A. Boulenger's Fauna of British India (1890) illustrating the terminology of shields on the head of a snake]]
The [[skin]] of a snake is covered in [[Snake scales|scale]]s. Contrary to the popular notion of snakes being slimy because of possible confusion of snakes with [[worm]]s, snakeskin has a smooth, dry texture. Most snakes use specialized belly scales to travel, gripping surfaces. The body scales may be smooth, [[keeled scales|keeled]], or granular. Snake's eyelids are transparent "spectacle" scales which remain permanently closed, also known as brille.

The shedding of scales is called ''[[ecdysis]]'', or, in normal usage ''[[moult]]ing'' or ''sloughing''. In the case of snakes, the complete outer layer of skin is shed in one layer.<ref name = "Smith1_30"> Smith, Malcolm A. Fauna of British India...Vol I - Loricata and Testudines, page 30 </ref> Snake scales are not discrete but extensions of the epidermis hence they are not shed separately, but are ejected as a complete contiguous outer layer of skin during each [[moult]], akin to a sock being turned inside out.<ref name="RSSlimy">[http://www.szgdocent.org/resource/rr/c-slimy.htm Are snakes slimy?] at [http://www.szgdocent.org/ Singapore Zoological Garden's Docent. Accessed 14 August 2006.</ref>

[[Moult]]ing serves a number of functions - firstly, the old and worn skin is replaced, secondly, it helps get rid of parasites such as mites and ticks. Renewal of the skin by [[moult]]ing is supposed to allow growth in some animals such as insects, however this view has been disputed in the case of snakes.<ref name="RSSlimy"/><ref name="ZooPax3"> [http://whozoo.org/ZooPax/ZPScales_3.htm ZooPax Scales Part 3]</ref>

Moulting is repeated periodically throughout a snake's life. Before a moult, the snake stops eating and often hides or moves to a safe place. Just prior to shedding, the skin becomes dull and dry looking and the eyes become cloudy or blue-colored. The inner surface of the old outer skin liquefies. This causes the old outer skin to separate from the new inner skin. After a few days, the eyes clear and the snake "crawls" out of its old skin. The old skin breaks near the mouth and the snake wriggles out aided by rubbing against rough surfaces. In many cases the cast skin peels backward over the body from head to tail, in one piece like an old sock. A new, larger, and brighter layer of skin has formed underneath.<ref name="RSSlimy"/><ref name = "GenSnakeInfo"> [http://www.sdgfp.info/Wildlife/Snakes/SnakeInfo.htm General Snake Information - Division of Wildlife, South Dakota]</ref>

An older snake may shed its skin only once or twice a year, but a younger, still-growing snake, may shed up to four times a year.<ref name = "GenSnakeInfo"/> The discarded skin gives a perfect imprint of the scale pattern and it is usually possible to identify the snake if this discard is reasonably complete and intact.<ref name="RSSlimy"/> Although the primary purpose of [[shedding]] is for the snake's growth; it also removes external [[parasite]]s. This periodic renewal has led to the snake being a symbol of healing and medicine, as pictured in the [[Rod of Asclepius]].<ref name=AIM>{{cite journal
|last=Wilcox
|first=Robert A
|last2=Whitham
|first2= Emma M
|title=The symbol of modern medicine: why one snake is more than two
|date=15 April 2003
|url=http://www.annals.org/cgi/content/full/138/8/673
|journal=Annals of Internal Medicine
|accessdate=2007-11-26}}</ref>

The shape and number of scales on the head, back and belly are characteristic to family, genus and species. Scales have a nomenclature analogous to the position on the body. In "advanced" ([[Caenophidia]]n) snakes, the broad belly scales and rows of [[dorsal scale]]s correspond to the [[vertebra]]e, allowing scientists to count the vertebrae without [[dissection]].

Scalation counts are also used to tell the sex of a snake when the species is not readily sexually dimorphic. A probe is inserted into the [[cloaca]] until it can go no further. The probe is marked at the point where it stops, removed, and compared to the subcaudal depth by laying it alongside the scales.<ref name="Rosenfeld_11"/> The scalation count determines whether the snake is a male or female as hemipenes of a male will probe to a different depth (usually shorter) than the cloaca of a female.<ref name="Rosenfeld_11"/>

==Perception==
[[Image:wiki snake eats mouse.jpg|thumb|250px|Thermographic image of a snake eating a mouse.]]
===Eyesight===
Snake [[Visual perception|vision]] is unremarkable. Generally vision is best in arboreal snakes and worst in burrowing snakes. Snakes can detect movement.<ref name="Cogger91_180"/> Some snakes, such the Asian vine snake (genus ''[[Ahaetulla]]''), have [[binocular vision]], with both eyes capable of focusing on the same point. Most snakes focus by moving the [[Lens (anatomy)|lens]] back and forth in relation to the [[retina]], as opposed to the human eye in which the lens is stretched.

===Smell===
Snakes use smell to track their prey. It smells by using its [[forked tongue]] to collect airborne particles then passing them to the [[Vomeronasal organ|''Jacobson's organ'' or the ''Vomeronasal organ'']] in the [[mouth]] for examination.<ref name="Cogger91_180">Cogger(1991), p.180</ref> The fork in the tongue gives the snake a sort of directional sense of smell and taste simultaneously.<ref name="Cogger91_180"/> The snake keeps its tongue constantly in motion, sampling particles from the air, ground, and water analyzing the chemicals found and determining the presence of prey or predators in its local environment.<ref name="Cogger91_180"/>

===Vibration sensitivity===
The part of the body which is in direct contact with the surface of the ground is very sensitive to vibration, thus a snake is able to sense other animals approaching through detecting faint vibrations in the air and on the ground.<ref name="Cogger91_180"/>

===Infrared sensitivity===
Pit vipers, pythons, and some boas have [[infrared sensing in snakes|infrared-sensitive receptors]] in deep grooves between the nostril and eye, although some have labial pits on their upper lip just below the nostrils(common in pythons) which allow them to "see" the radiated heat.<ref name="Cogger91_180"/> Infrared sensitivity helps snakes locate nearby prey, especially warm-blooded mammals.

==Internal organs==
{{snake anatomy imagemap}}
As with all reptiles, snakes are [[ectothermic]] ("cold-blooded"). They possess a three-chambered heart composed of two [[Atrium (heart)|atria]] and one large [[Ventricle (heart)|ventricle]].<ref name="Mader"/> Although more evolutionary basic than the mammalian four-chambered heart, it functions in a similar manner because of divisions and valves within the ventricle.<ref name="Mader"/> The oxygenated blood, therefore mingles with the venous blood to an extent.

The snake's heart is encased in a sac, called the ''[[pericardium]]'', located at the [[:wiktionary:bifurcation|bifurcation]] of the [[bronchi]]. The heart is able to move around, however, due to the lack of a diaphragm. This adjustment protects the heart from potential damage when large ingested prey is passed through the esophagus. The [[spleen]] is attached to the [[gall bladder]] and [[pancreas]] and filters the blood. The [[thymus gland]] is located in fatty tissue above the heart and is responsible for the generation of immune cells in the blood. The cardiovascular system of snakes is also unique due to the presence of a renal portal system in which the blood from the snake's tail passes through the kidneys before returning to the heart.<ref name="Mader"/>

The [[vestige|vestigial]] left [[lung]] is often small or sometimes even absent, as snakes' tubular bodies require all of their organs to be long and thin.<ref name="Mader">
{{Citation
| last = Mader
| first = Douglas
| title = Reptillian Anatomy
| journal = Reptiles
| volume =3
| issue =2
| pages =84-93
| date = June 1995
| year = 1995
}}
</ref> In the majority of species, only one [[lung]] is functional. This lung contains a vascularized anterior portion and a posterior portion which does not function in gas exchange.<ref name="Mader"/> This 'saccular lung' is used for [[hydrostatic]] purposes to adjust buoyancy in some aquatic snakes and its function remains unknown in terrestrial species.<ref name="Mader"/> Many organs that are paired, such as [[kidneys]] or [[reproductive organs]], are staggered within the body, with one located ahead of the other.<ref name="Mader"/> Snakes have no colenary bladder or [[lymph node]]s.<ref name="Mader"/>

==Locomotion==
As snakes have no limbs, they have adapted various methods to move on land or in water.<ref name="Cogger91_175">Cogger(1991), p.175</ref> [[Lateral undulation]] is the sole mode of aquatic locomotion, and the most common mode of terrestrial locomotion.<ref name="Cogger91_175"/> In this mode, the body of the snake alternately flexes to the left and right, resulting in a series of rearward-moving 'waves'.<ref name="Cogger91_175"/> When swimming, the waves become larger as they move down the snake's body, and the wave travels backwards faster than the snake moves forwards.<ref name="Cogger91_175"/> This contrasts with terrestrial lateral undulation, in which the wave speed is precisely the same as the snake speed, and as a result, every point on the snake's body follows the path of the point ahead of it, allowing snakes to move through very dense vegetation and small openings.<ref name="Cogger91_175"/> In aquatic lateral undulation, snakes generate forward thrust by pushing their body against the water, resulting in the observed slip, while in terrestrial lateral undulation, thrust is generated by pushing against irregularities in the substrate such as pebbles and grass, resulting in 'path following'.<ref name="Cogger91_175"/> In spite of overall similarities, studies show that the pattern of muscle activation is substantially different in aquatic vs terrestrial lateral undulation, which justifies calling them separate modes. All snakes can laterally undulate forwards (with backward-moving waves), but only [[sea snakes]] have been observed reversing the pattern, i.e. moving backwards via forward-traveling waves.

[[Image:CrolatusScutulatusSidewindingSnake.jpg|thumb|left|Mojave rattlesnake, sidewinding]]
When the snake must move in an environment which lacks any irregulaties to push against, such as a slick mud flat or sand dune, colubroid snakes (colubrids, elapids, and vipers) usually employ [[sidewinding]].<ref name="Cogger91_176">Cogger(1991), p.176</ref> Most common in short, stocky snakes, sidewinding is a modified form of lateral undulation in which all of the body segments oriented in one direction remain in contact with the ground, while the other segments are lifted up, resulting in a peculiar 'rolling' motion.<ref name="Cogger91_177">Cogger(1991), p.177</ref> Contrary to some sources, there is no evidence that sidewinding is associated with hot sand.<ref name="Cogger91_177"/>

Both sidewinding and lateral undulation require substantial space, but some environments, such as tunnels, have very limited space and in these instances snakes rely on concertina locomotion.<ref name="Cogger91_177"/> In this mode, the snake braces the posterior portion of its body against the tunnel wall while the front of the snake extends and straightens.<ref name="Cogger91_177"/> The front portion then flexes and forms an anchor point, and the posterior is straightened and pulled forwards.<ref name="Cogger91_177"/>

The slowest mode of snake locomotion is [[rectilinear locomotion]], which is also the only one in which the snake does not bend its body laterally.<ref name="Cogger91_176"/> In this mode, the belly scales are lifted and pulled forward before being placed down and the body pulled over them. Waves of movement and stasis pass posteriorly, resulting in a series of ripples in the skin.<ref name="Cogger91_176"/> The ribs of the snake do not move in this mode of locomotion and this method is most often used by large [[Python (genus)|python]]s, [[boa]]s, and [[pit viper]]s when stalking prey across open ground as the snake's movements are subtle and harder to detect by their prey in this manner.<ref name="Cogger91_177"/>

The movement of snakes in arboreal habitats has only recently been studied.<ref name="Cogger91_177"/> While on tree branches, snakes use several modes of locomotion depending on species and bark texture.<ref name="Cogger91_177"/> However, gliding snakes ([[Chrysopelea]]) of Southeast Asia launch themselves from branch tips, by spreading their ribs and laterally undulating as they glide between trees. <ref name="Cogger91_177"/><ref>Freiberg(1984). p.135</ref>

==Reproduction==
Although a wide range of reproductive modes are used by snakes; all snakes employ [[internal fertilization]], accomplished by means of paired, forked [[hemipenis|hemipenes]], which are stored inverted in the male's tail.<ref name="Capula89_117">Capula (1989), p.117</ref> The hemipenes are often grooved, hooked, or spined in order to grip the walls of the female's [[cloaca]].<ref name="Capula89_117"/>

Most species of snake lay [[egg (biology)|eggs]], and most of those species abandon them shortly after laying; however, individual species such as the [[King cobra]] actually construct nests and stay in the vicinity of the hatchlings after incubation.<ref name="Capula89_117"/> Most pythons coil around their egg-clutches after they have laid them and remain with the eggs until they hatch.<ref name="Cogger91_186">Cogger (1991), p.186</ref> The female python will not leave the eggs, except to occasionally bask in the sun or drink water and will generate heat to incubate the eggs by shivering.<ref name="Cogger91_186"/>

Some species of snake are [[Ovoviviparity|ovoviviparous]] and retain the eggs within their bodies until they are almost ready to hatch.<ref name="Capula89_118">Capula (1989), p.118</ref><ref name="Cogger91_182">Cogger (1991), p.182</ref> Recently, it has been confirmed that several species of snake are fully [[Vivipary|viviparous]], such as the [[boa constrictor]] and [[green anaconda]], nourishing their young through a [[placenta]] as well as a [[yolk sac]], which is highly unusual among reptiles, or anything else outside of [[placental mammals]].<ref name="Capula89_118"/><ref name="Cogger91_182"/> Retention of eggs and live birth are most often associated with colder environments, as the retention of the young within the [[female]].<ref name="Capula89_117"/><ref name="Cogger91_182"/>

== Venom ==
{{see also|Snake venom}}
[[Image:ViperaBerusFang.JPG|thumb|200px|left|[[Vipera berus]], one fang with a small venom stain in glove, the other still in place]]
Cobras, vipers, and closely related species use [[venom]] to immobilize or kill their prey. The venom is modified [[saliva]], delivered through [[snake venom|fang]]s.<ref name= "Mehrtens87_243">Mehrtens (1987), p.243</ref> The fangs of 'advanced' venomous snakes like viperids and elapids are hollow in order to inject venom more effectively, while the fangs of rear-fanged snakes such as the Boomslang merely have a groove on the posterior edge to channel venom into the wound. Snake venoms are often prey specific, its role in self-defense is secondary.<ref name= "Mehrtens87_243"/> Venom, like all salivary secretions, is a pre-digestant which initiates the breakdown of food into soluble compounds allowing for proper digestion and even "non-venomous" snake bites (like any animal bite) will cause tissue damage.<ref name="Mehrtens87_209">Mehrtens (1987), p.209</ref>

Certain birds, mammals, and other snakes such as [[kingsnake]]s that prey on venomous snakes have developed resistance and even immunity to certain venom.<ref name= "Mehrtens87_243"/> Venomous snakes include three [[family (biology)|families]] of snakes and do not constitute a formal [[taxonomic classification|classification]] group used in [[taxonomy]]. The term '''poisonous snake''' is mostly incorrect - poison is inhaled or ingested whereas venom is injected.<ref name="Freiberg84_125"/> There are, however, two examples - [[Rhabdophis]] sequesters toxins from the toads it eats then secretes them from nuchal glands to ward off predators, and a small population of [[garter snakes]] in Oregon retains enough toxin in their liver from the newts they eat to be effectively poisonous to local small predators such as crows and foxes.<ref name="Freiberg84_123">Freiberg (1984), p.123</ref>

Snake venoms are complex mixtures of [[protein]]s and are stored in poison glands at the back of the head.<ref name="Freiberg84_123"/> In all venomous snakes these glands open through ducts into grooved or hollow teeth in the upper jaw.<ref name= "Mehrtens87_243"/><ref name="Freiberg84_125">Freiberg (1984), p.125</ref> These proteins can potentially be a mix of [[neurotoxin]]s (which attack the nervous system), [[hemotoxin]]s (which attack the circulatory system), [[cytotoxin]]s, [[bungarotoxin]]s and many other toxins that affect the body in different ways.<ref name="Freiberg84_125"/> Almost all snake venom contains ''hyaluronidase'', an enzyme that ensures rapid diffusion of the venom.<ref name= "Mehrtens87_243"/>

Venomous snakes that use hemotoxins usually have the fangs that secrete the venom in the front of their mouths, making it easier for them to inject the venom into their victims.<ref name="Freiberg84_125"/> Some snakes that use neurotoxins, such as the [[Boiga dendrophila|mangrove snake]], have their fangs located in the back of their mouths, with the fangs curled backwards.<ref name="Freiberg84_126">Freiberg (1984), pp.126</ref> This makes it both difficult for the snake to use its venom and for scientists to milk them.<ref name="Freiberg84_125"/> ''[[elapid|Elapid]]'' snakes, however, such as [[cobra]]s and [[krait]]s are ''proteroglyphous'', possessing hollow fangs which cannot be erected toward the front of their mouths and cannot "stab" like a viper, they must actually bite the victim.<ref>Mehrtens (1987), p.242</ref>

It has recently been suggested that all snakes may be venomous to a certain degree, the harmless snakes having weak venom and no fangs.<ref name="Fry_2006_earlyevolution">
{{citation | last = Fry | first = Brian G | last2 = Vidal | first2 = Nicholas | last3 = Norman | first3 = Janette A. | last4 = Vonk | first4 = Freek J. | last5 = Scheib | first5 = Holger | last6 = Ramjan | first6 = Ryan | last7 = Kuruppu | first7 = Sanjaya | title = Early evolution of the venom system in lizards and snakes. | journal = Nature (Letters) | volume = 439 | pages = 584-588 | year = 2006 | doi = 10.1038/nature04328 }}</ref>

Snakes may have evolved from a common lizard ancestor that was venomous, from which venomous lizards like the [[gila monster]] and [[beaded lizard]] may have also derived. They share this [[venom clade]] with various other [[sauria]]n species.

Venomous snakes are classified in two [[taxonomy|taxonomic]] [[family (biology)|families]]:
*[[Elapid]]s - [[cobra]]s including [[King Cobra|king cobras]], [[Bungarus|krait]]s, [[mamba]]s, [[Austrelaps|Australian copperhead]]s, [[sea snake]]s, and [[coral snake]]s.<ref name="Freiberg84_126"/>
*[[Viperidae|Viperids]] - [[Viperidae|viper]]s, [[rattlesnake]]s, [[Agkistrodon contortrix|copperhead]]s/[[Agkistrodon piscivorus|cottonmouth]]s, [[adder (snake)|adder]]s and [[Lachesis (genus)|bushmaster]]s.<ref name="Freiberg84_126"/>

There is a third family containing the ''opistoglyphous'' (rear-fanged)snakes as well as the majority of other snake species:
*[[Colubrid]]s - [[boomslang]]s, tree snakes, [[Ahaetulla|vine snake]]s, [[boiga|mangrove snake]]s, although not all [[colubrid]]s are [[venomous]].<ref name="Mehrtens87_209"/><ref name="Freiberg84_126"/>

==Interactions with humans==

=== Snake bite ===
{{main|Snake bite}}
[[Image:Baumpython.jpg|thumb|200px|left|Coiled up Green tree python ''[[Morelia viridis]]'']]
Snakes do not ordinarily prey on humans and most will not attack humans unless the snake is startled or injured, preferring instead to avoid contact. With the exception of large constrictors, non-venomous snakes are not a threat to humans. The bite of non-venomous snakes are usually harmless because their teeth are designed for grabbing and holding, rather than tearing or inflicting a deep puncture wound. Although the possibility of an infection and tissue damage is present in the bite of a non-venomous snake; venomous snakes present far greater hazard to humans.<ref name="Mehrtens87_209"/>

Documented deaths resulting from snake bites are uncommon. Non-fatal bites from venomous snakes may result in the need for amputation of a limb or part thereof. Of the roughly 725 species of venomous snakes worldwide, only 250 are able to kill a human with one bite. Although [[Australia]] is home to the largest number of venomous snakes in the world, about one snakebite proves venomous, on average, in a year; in [[India]] where 250,000 snakebites are recorded in a single year, as many as 50,000 initial deaths are recorded. <ref name="Sinha">
{{Citation
| last =Sinha
| first =Kounteya
| author-link =
| title = No more the land of snake charmers...
| newspaper = The Times of India
| pages =
| year =2006
| date =25 Jul 2006
| url =http://timesofindia.indiatimes.com/articleshow/1803026.cms }}
</ref>

The treatment for a snakebite is as variable as the bite itself. The most common and effective method is through [[antivenin]], a serum made from the venom of the snake. Some antivenom is species specific or monovalent and some is made for use with multiple species in mind also known as polyvalent. In the United States for example, all species of venomous snakes are [[pit viper]]s, with the exception of the [[coral snake]]. To produce antivenin, a mixture of the venoms of the different species of [[rattlesnake]]s, copperheads, and cottonmouths is injected into the body of a horse in ever-increasing dosages until the horse is immunized. Blood is then extracted from the immunized horse and freeze-dried. It is reconstituted with sterile water and becomes antivenin. For this reason, people who are allergic to horses cannot be treated using antivenin. Antivenin for the more dangerous species (such as [[mamba]]s, [[taipan]]s, and [[cobra]]s) is made in a similar manner in India, South Africa, and Australia with the exception being that those antivenins are species-specific.

snakes bites with venom can lead to hair loss,aids,t-cell supression,and scarring

===Snake charmers===
{{main|Snake charming}}
[[Image:Snake in basket.jpg|thumb|right|200px|[[Indian Cobra]] in a basket being charmed]]In some parts of the world, especially in [[India]], [[snake charming]] is a roadside show performed by a charmer. In such a show, the snake charmer carries a basket that contains a snake that he seemingly charms by playing tunes from his flute-like musical instrument, to which the snake responds.<ref name="Bagla"/> Snakes lack external ears, though have internal ears. However, snakes show no tendency to be influenced by music.<ref name="Bagla">
{{cite news
| last=Bagla
| first=Pallava
| title=India's Snake Charmers Fade, Blaming Eco-Laws, TV
| date=April 23, 2002
| publisher=National Geographic News
| url=http://news.nationalgeographic.com/news/2002/04/0417_020423_snakecharm_2.html
| accessdate = November 26, 2007}}</ref>

Researchers have pointed out that many of these snake charmers are good sleight-of-hand artists. The snake moves correspondingly to the flute movement and the vibrations from the tapping of the charmer's foot, neither of which is noticed by the public. Charmers rarely catch their snakes and the snakes are either nonvenomous or defanged cobras. Other snake charmers also have a snake and [[mongoose]] show, where both the animals have a mock fight; however, this is not very common, as the snakes, as well as the mongooses, may be seriously injured or killed.

Snake charming as a profession is now discouraged in India as a contribution to forest and snake conservation. In fact, in some places in India snake charming is banned by law.<ref name="Bagla"/>

===Snake trapping===
The tribals of "Irulas" from [[Andhra Pradesh]] and [[Tamil Nadu]] in [[India]] have been hunter-gatherers in the hot dry plains forests and have practiced this art for generations. They have a vast knowledge of snakes in the field. Irulas generally catch the snakes with the help of a simple stick. Earlier, the Irulas caught thousands of snakes for the snake-skin industry. After the complete ban on snake-skin industry in India and protection of all snakes under the [[Wildlife Protection Act of 1972|Indian Wildlife (Protection) Act 1972]], they formed the Irula Snake Catcher's Cooperative and switched to catching snakes for removal of venom, releasing them in the wild after four extractions. The venom so collected is used for producing life-saving [[antivenin]], biomedical research and for other medicinal products.<ref name="Whitaker et al"> Whitaker, Romulus & Captain, Ashok. ''Snakes of India: The Field Guide''.(2004) pp 11 to 13.</ref> The Irulas are also known to eat some of the snakes they catch and are very useful in rat extermination in the villages.

Despite the existence of snake charmers, there have also been professional snake catchers or wranglers. Modern day snake trapping involves a [[herpetologist]] using a long stick with a "V" shaped end. Some like [[Bill Haast]], [[Austin Stevens]], and [[Jeff Corwin]] prefer to catch them using bare hands.
<!--At least one tribe uses a specialized form of snake catching as a rite of passage to manhood.{{Fact|date=February 2007}} The young man of interest will wrap his leg heavily in some type of cloth all the way to the inseam. He will then stick his leg in a burrow containing a large python, typically a [[Python reticulatus|reticulated python]]. After the snake swallows most of his leg several other members of the tribe will pull him out of the hole along with the snake. The snake is then killed and the man's leg removed from the snake. These snakes can be over 20&nbsp;ft long and it is possible for the man to have his leg dislocated. The scent of a prey animal may be used to help convince the snake to swallow the leg. Snakes have a single-track digestive system, but the digestion process is actually much slower.
Commented this para out till the tribe is identified and a reference given/. -->

===Consumption of snakes===
[[Image:Heron with snake.JPG|thumb|250px|[[Great Blue Heron]] with a snake]]
While not commonly thought of as a dietary item by most cultures, in some cultures, the consumption of snakes is acceptable, or even considered a delicacy, prized for its alleged pharmaceutical effect of warming the heart.<ref>{{cite web
|title=Dining Guide Chinese Cuisine
|url=http://www.asiatour.com/x-librar/dining/chinese.htm |accessdate=11/27/2007}}</ref> Western cultures document the consumption of snakes under extreme circumstances of hunger.<ref>Irvine, F. R. 1954. Snakes as food for man. British Journal of Herpetology. 1(10):183-189.</ref> Cooked rattlesnake meat is an exception, which is commonly consumed in parts of the Midwestern United States. In Asian countries such as [[Thailand]], [[Indonesia]], and [[Cambodia]], drinking the blood of snakes, particularly the cobra, is believed to increase sexual virility.<ref name="Flynn">
{{cite news
| last=Flynn
| first=Eugene
| title=Flynn Of The Orient Meets The Cobra
| date=April 23, 2002
| publisher=Fabulous Travel
| url=http://www.fabuloustravel.com/gourmet/travel/cobrasblood/cobra.html
| accessdate = November 26, 2007}}</ref> The blood is drained while the cobra is still alive when possible, and is usually mixed with some form of liquor to improve the taste.<ref name="Flynn"/>

In some Asian countries, the use of snakes in alcohol is also accepted. In such cases, the body of a snake or several snakes is left to steep in a jar or container of liquor. It is claimed that this makes the liquor stronger (as well as more expensive). One example of this is the [[Habu]] snake sometimes placed in the [[Okinawa]]n liquor [[Awamori]] also known as "Habu Sake".<ref name="Allen">
{{cite news
| last=Allen
| first=David
| title=Okinawa’s potent habu sake packs healthy punch, poisonous snake
| date=Sunday, July 22, 2001
| publisher=[[Stars and Stripes]]
| url=http://ww2.pstripes.osd.mil/01/mag/sm072201c.html
| accessdate = November 26, 2007}}</ref>

===Snakes as pets===
In the Western world some snakes, especially docile species such as the [[Python regius|ball python]] and [[Corn Snake|corn snake]], are kept as pets. To supply this demand a [[herpetoculture|captive breeding]] industry has developed. Snakes bred in captivity tend to make better pets and are considered preferable to wild caught specimens.

===Symbolism===
[[Image:Medusa by Carvaggio.jpg|thumb|200px|right|[[Medusa]] by 16th Century Italian artist [[Caravaggio]]]]
[[Image:Rod of asclepius.jpg|thumb|300px|Rod of Asclepius, in which the snakes, through [[ecdysis]], symbolize healing.]]
{{main|Serpent (symbolism)}}

In [[History of Egypt|Egyptian history]], the snake occupies a primary role with the Nile cobra adorning the crown of the pharaoh in ancient times. It was [[snake worship|worshipped]] as one of the gods and was also used for sinister purposes: murder of an adversary and ritual suicide ([[Cleopatra VII of Egypt|Cleopatra]]).

In [[Greek Mythology|Greek mythology]] snakes are often associated with deadly and dangerous antagonists, but this is not to say that snakes are symbolic of evil; in fact, snakes are a [[chthonic]] symbol, roughly translated as 'earthbound'. The nine-headed [[Lernaean Hydra]] that [[Hercules ]] defeated and the three [[Gorgon]] sisters are children of Gaia, the earth.<ref name="BF85">Bullfinch (2000) p. 85</ref> [[Medusa]] was one of the three Gorgon sisters who [[Perseus ]] defeated.<ref name="BF85"/> Medusa is described as a hideous mortal, with snakes instead of hair and the power to turn men to stone with her gaze.<ref name="BF85"/> After killing her, Perseus gave her head to [[Athena]] who fixed it to her shield called the [[Aegis]].<ref name="BF85"/> The [[Titan (mythology)|Titans]] are also depicted in art with snakes instead of legs and feet for the same reason—they are children of Gaia and Ouranos (Uranus), so they are bound to the earth.

Three medical symbols involving snakes that are still used today are [[Bowl of Hygieia]], symbolizing pharmacy, and the [[Caduceus]] and [[Rod of Asclepius]], which are symbols denoting medicine in general.<ref name=AIM>{{cite journal|last=Wilcox|first=Robert A|coauthors=Whitham, Emma M|title=The symbol of modern medicine: why one snake is more than two|date=15 April 2003|url=http://www.annals.org/cgi/content/full/138/8/673|journal=Annals of Internal Medicine|accessdate=2007-12-04}}</ref>

[[India]] is often called the land of snakes and is steeped in tradition regarding snakes.<ref name="Deane_61"/> Snakes are worshipped as gods even today with many women pouring [[milk]] on snake pits (despite snakes' aversion for milk).<ref name="Deane_61">Deane (1833). p.61</ref> The cobra is seen on the neck of [[Shiva]] and [[Vishnu]] is depicted often as sleeping on a 7 headed snake or within the coils of a serpent.<ref>Deane (1833). p.62-64</ref> There are also several temples in India solely for cobras sometimes called ''Nagraj'' (King of Snakes) and it is believed that snakes are symbols of fertility. There is a Hindu festival called [[Nag Panchami]] each year on which day snakes are venerated and prayed to. See also ''[[Nāga]]''.

In [[Islam]], [[Christianity]] and [[Judaism]] the snake makes its infamous appearance in the first book ([[Genesis]] 3:1) of the [[Bible]] when a serpent appears before the first couple [[Adam and Eve]] as an agent of the devil and tempts them with the [[forbidden fruit]] from the [[Tree of Life]]. The snake returns in [[Exodus]] when [[Moses]], as a sign of God's power, turns his staff into a snake and when Moses made the [[Nehushtan]], a bronze snake on a pole that when looked at cured the people of bites from the snakes that plagued them in the desert. The serpent makes its final appearance symbolizing [[Satan]] in the [[Book of Revelation]]:"And he laid hold on the dragon the old serpent, which is the devil and Satan, and bound him for a thousand years." (Revelation 20:2)

The [[Ouroboros]] is a symbol that is associated with many different religions and customs, and is also claimed to be related to [[Alchemy]]. The Ouroboros or Oroboros is a snake eating its own tail in a clock-wise direction (from the head to the tail) in the shape of a circle, representing manifestation of one's own life and rebirth, leading to immortality.

The [[Snake (zodiac)|snake]] is one of the 12 celestial animals of [[Chinese Zodiac]], in the [[Chinese calendar]].

Many ancient Peruvian cultures worshipped nature.<ref> Benson, Elizabeth, The Mochica: A Culture of Peru. New York, NY: Praeger Press. 1972</ref> They placed emphasis on animals and often depicted snakes in their art.<ref>Berrin, Katherine & Larco Museum. ''The Spirit of Ancient Peru:Treasures from the [[Larco_Museum|Museo Arqueológico Rafael Larco Herrera]].'' New York: [[Thames and Hudson]], 1997.</ref>

===In religion===
[[Muhammad]], the prophet of [[Islam]] was reported to have said to "Kill the snake with two white lines on its back, for it blinds the on-looker and causes [[abortion]]." <ref>{{Bukhari|4|54|527}}</ref>

==See also==
[[Image:SnakesCupisnique200BC.jpg|thumb|right|200px|Cupisnique Snake. 200 B.C.[[Larco_Museum|Larco Museum Collection]] Lima, Peru.]]
'''Snakes'''

* [[Snake skeleton]]
* [[Venomous snake]]
* [[List of snakes]]
* [[List of Serpentes families]]
* [[Limbless vertebrates]]

'''Snakes in culture'''
* [[Snakebot]]
* [[Snake-arm robot]]
* [[Snake oil]]
* [[Exploding snake]]
* [[Snake Shyam]]
* [[Snakes on a Plane]]
* [[Serpent Mound]]

==Cited references==
{{reflist|3}}

==References==
* {{ITIS|ID=174118|taxon=Serpentes|year=2007|date=6 December}}
*{{cite book | last = Bebler | first = John L. | last2 = King | first2 = F. Wayne | title = The Audubon Society Field Guide to Reptiles and Amphibians of North America | publisher = Alfred A. Knopf |Location= New York | pages = 581 | date= 1979 | isbn = 0394508246}}
* {{cite book | last =Bullfinch | first =Thomas | authorlink =Thomas Bullfinch | title =Bullfinch's Complete Mythology
| publisher =Chancellor Press | date =2000 | location =[[London]]
| pages =679 | url =http://etext.library.adelaide.edu.au/b/bulfinch/thomas/
| isbn =0753703815 }}
*{{cite book |last= Capula|first= Massimo|coauthors =Behler|title= Simon & Schuster's Guide to Reptiles and Amphibians of the World |year= 1989||publisher= [[Simon & Schuster]] |location= [[New York]]|isbn= 0671690981}}
*{{cite book |last= Coborn|first= John| title=The Atlas of Snakes of the World| year= 1991| location=[[New Jersey]]| publisher = TFH Publications| ISBN= 9780866227490}}
*{{cite book | last = Cogger | first = Harold | authorlink = Harold Cogger | last2 = Zweifel | first2 = Richard | title = Reptiles & Amphibians | publisher = Weldon Owen | location = [[Sydney, Australia]] |date = 1992 | isbn = 0831727861}}
*{{cite book | last =Conant | first =Roger | last2 =Collins | first2 =Joseph |authorlink=Roger Conant (herpetologist) | title =A Field Guide to Reptiles and Amphibians Eastern/Central North America | publisher =Houghton Mifflin Company | date= 1991 | location =[[Boston]], [[Massachusetts]] | isbn = 0395583896 }}
*{{cite book | last =Deane | first =John | authorlink =The Worship of the Serpent | title =The Worship of the Serpent | publisher =Kessinger Publishing | date =1833 | location =[[Whitefish, Montana|Whitefish]], [[Montana]]| pages =412| url =http://www.sacred-texts.com/etc/wos/index.htm | isbn =1564598985 }}
*{{cite book | last =Ditmars | first =Raymond L | authorlink =Raymond Ditmars | title = Poisonous Snakes of the United States: How to Distinguish Them
| publisher =E. R. Sanborn | date =1906 | location =[[New York]] | pages =11}}
*{{cite book | last =Ditmars | first =Raymond L | authorlink =Raymond Ditmars | title = Snakes of the World | publisher =Macmillian | date =1931
| location =[[New York]] | pages =11 | isbn = 978-0025317307 }}
*{{cite book | last =Ditmars | first =Raymond L | authorlink =Raymond Ditmars | title = Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres | publisher =Macmillian | date =1933 | location =[[New York]] | pages =321}}
*{{cite book | last =Ditmars | first =Raymond L |coauthor = W. Bridges | authorlink =Raymond Ditmars | title = Snake-Hunters' Holiday. | publisher =D. Appleton and Company | date =1935 | location =[[New York]] | pages =309}}
*{{cite book | last =Ditmars | first =Raymond L | authorlink =Raymond Ditmars | title = A Field Book of North American Snakes | publisher =Doubleday, Doran & Co | date =1939 | location =[[Garden City, New York|Garden City]],[[New York]] | pages =305}}
*{{cite book |last= Freiberg|first= Dr. Marcos|last2= Walls|first2=Jerry |title= The World of Venomous Animals|year= 1984
|publisher= TFH Publications|location=[[ New Jersey]] |isbn= 0876665679}}
*{{cite book | last =Gibbons | first =J. Whitfield | last2 =Gibbons | first2 =Whit | title =Their Blood Runs Cold: Adventures With Reptiles and Amphibians | publisher =[[University of Alabama]] Press | date =1983 | location =[[Alabama]] | pages =164 |isbn=978-0817301354 }}
*{{cite book | last =Mattison | first =Chris | title =The New Encyclopedia of Snakes | publisher =[[Princeton University]] Press | date =2007 | location =[[New Jersey]] | pages =272|isbn=978-0691132952 }}
*{{cite book | last=McDiarmid | first=RW | last2= Campbell |first2=JA | last3=Touré| first3=T|year= 1999|title= Snake Species of the World: A Taxonomic and Geographic Reference |volume= 1 |publisher= Herpetologists' League |pages=511 | ISBN= 1893777006 }}
*{{cite book |last= Mehrtens|first= John|title= Living Snakes of the World in Color|year= 1987|publisher= Sterling
|location= [[New York]]|isbn= 0806964618}}
*{{cite book | author=[[Romulus Whitaker]] (English edition); Tamil translation by O.Henry Francis | title=நம்மை சுட்ரியுள்ள பாம்புகள் (Snakes around us, Tamil) | publisher=National Book Trust | year=1996 | id=ISBN 81-237-1905-1}}
*{{cite book |last = Rosenfeld | first = Arthur | title = Exotic Pets | publisher = [[Simon & Schuster]] | location= [[New York]] | date= 1989 | pages=293|isbn = 067147654}}
*{{cite book |last =Spawls| first=Steven|last2 =Branch |first2= Bill |year= 1995 |title= The Dangerous Snakes of Africa |publisher=Ralph Curtis Publishing| location=[[Sanibel Island]],[[Florida]]|pages= 192 |isbn = 0883590298}}

==External links==
{{commonscat|Serpentes}}

*[http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=174118 Integrated Taxonomic Information System] (USDA)
*[http://www.science2day.info/ Snakes in tropical countries]
* [http://www.naturemagics.com/stock-photo/thumbnails.php?album=7 Snakes of the Indian Subcontinent]
* [http://www.smithsonianeducation.org/educators/lesson_plans/herps/start.html Research Guides for Reptile Study] (Smithsonian)
* [http://www.reptile-database.org/ EMBL Database]

* [http://www.snakecell.org Snake Cell -- Large DB about snake
* [http://www.reptil.de European Snakes -- Large DB and Pictures about snakes]
* [http://www.venom-center.com/ Venomous Snakes Information Community]
* [http://www.reptilesweb.com/reptiles-section/snake-world.html Snake World - Several Types of Snakes]
* [http://www.oplin.org/snake What's That Snake? Snake Identification Tool] (OPLIN)
* [http://erudite.110mb.com/worlds-top-10-most-poisonous-venomous-toxic-snakes/ Worlds Top 10 Most Poisonous Snakes - Toxic Ranking]
* [http://artedi.nrm.se/nrmherps/qbrowse.php?FormData=scientificName Swedish Museum of Natural History Herpetology Database]






{{Snake_families}}

[[Category:Snakes| ]]

[[ar:ثعبان]]
[[ay:Asiru]]
[[bn:সাপ]]
[[zh-min-nan:Choâ]]
[[bs:Zmija]]
[[br:Naer]]
[[bg:Змии]]
[[ca:Serp]]
[[ceb:Serpent]]
[[cs:Hadi]]
[[ch:Kolepbla]]
[[cy:Neidr]]
[[da:Slange]]
[[de:Schlangen]]
[[nv:Tł’iish]]
[[el:Φίδι]]
[[es:Serpentes]]
[[eo:Serpento]]
[[fa:مار]]
[[fr:Serpentes]]
[[gl:Cobra]]
[[glk:میلؤم]]
[[ko:뱀]]
[[hr:Zmije]]
[[id:Ular]]
[[it:Serpentes]]
[[he:נחשים]]
[[ka:გველები]]
[[kw:Sarf]]
[[la:Serpens]]
[[lv:Čūskas]]
[[lt:Gyvatės]]
[[li:Slange]]
[[hu:Kígyók]]
[[ml:പാമ്പ്‌]]
[[mt:Serp]]
[[mr:साप]]
[[ms:Ular]]
[[cdo:Siè]]
[[nah:Cōātl]]
[[nl:Slangen]]
[[ja:ヘビ]]
[[no:Slanger]]
[[nn:Orm]]
[[nrm:Tchilieuvre]]
[[pl:Węże]]
[[pt:Cobra]]
[[ro:Şarpe]]
[[qu:Mach'aqway]]
[[ru:Змеи]]
[[se:Gearpmaš]]
[[scn:Scursuni]]
[[simple:Snake]]
[[sk:Hady]]
[[sl:Kače]]
[[sr:Змије]]
[[su:Oray]]
[[fi:Käärmeet]]
[[sv:Ormar]]
[[ta:பாம்பு]]
[[te:పాము]]
[[th:งู]]
[[vi:Rắn]]
[[tr:Yılan]]
[[uk:Змії]]
[[yi:שלאנג]]
[[zh:蛇亚目]]

Revision as of 02:23, 14 February 2008

fuck you bicth thats what a snake says

Retrieved from "https://en.wikipedia.org/w/index.php?title=Snake&oldid=191330750"