Snake

The English word snake comes from Old English , itself from Proto-Germanic (cf. Germanic 'ring snake', Swedish 'grass snake'), from Proto-Indo-European root 'to crawl to creep', which also gave sneak as well as Sanskrit 'snake'. The word ousted adder, as adder went on to narrow in meaning, though in Old English was the general word for snake. The other term, serpent, is from French, ultimately from Indo-European 'to creep', which also gave Ancient Greek () 'I crawl' and Sanskrit 'snake'. == Taxonomy ==

All modern snakes are grouped within the suborder Serpentes in Linnean taxonomy, part of the order Squamata, though their precise placement within squamates remains controversial. The two infraorders of Serpentes are Alethinophidia and Scolecophidia. While not extant today, the Madtsoiidae, a family of giant, primitive, python-like snakes, lived until 50,000 years ago in Australia, represented by genera such as Wonambi. Recent molecular studies support the monophyly of the clades of modern snakes, scolecophidians, typhlopids + anomalepidids, alethinophidians, core alethinophidians, uropeltids (Cylindrophis, Anomochilus, uropeltines), macrostomatans, booids, boids, pythonids and caenophidians. Families Legless lizards While snakes are limbless reptiles, evolved from (and grouped with) lizards, there are many other species of lizards that have lost their limbs independently but which superficially look similar to snakes. These include glass snakes (including the slowworm), and amphisbaenians. Evolution }} The fossil record of snakes is relatively poor because snake skeletons are typically small and fragile making fossilization uncommon. Fossils readily identifiable as snakes (though often retaining hind limbs) first appear in the fossil record during the Cretaceous period. The earliest known true snake fossils (members of the crown group Serpentes) come from the marine simoliophiids, the oldest of which is the Late Cretaceous (Cenomanian age) Haasiophis terrasanctus from the West Bank, dated to between 112 and 94 million years old. Based on genomic analysis it is certain that snakes descend from lizards. Previously, snakes were a minor component of the North American fauna, but during the Miocene, the number of species and their prevalence increased dramatically with the first appearances of vipers and elapids in North America and the significant diversification of Colubridae (including the origin of many modern genera such as Nerodia, Lampropeltis, Pituophis, and Pantherophis). An early fossil snake relative, Najash rionegrina, was a two-legged burrowing animal with a sacrum, and was fully terrestrial. Najash, which lived 95 million years ago, also had a skull with several features typical for lizards, but had evolved some of the mobile skull joints that define the flexible skull in most modern snakes. The species did not show any resemblances to the modern burrowing blind snakes, which have often been seen as the most primitive group of extant forms. One extant analog of these putative ancestors is the earless monitor Lanthanotus of Borneo (though it is also semiaquatic). Subterranean species evolved bodies streamlined for burrowing, and eventually lost their limbs. This hypothesis was strengthened in 2015 by the discovery of a 113-million-year-old fossil of a four-legged snake in Brazil that has been named Tetrapodophis amplectus. It has many snake-like features, is adapted for burrowing and its stomach indicates that it was preying on other animals. It is currently uncertain if Tetrapodophis is a snake or another species, in the squamate order, as a snake-like body has independently evolved at least 26 times. Tetrapodophis does not have distinctive snake features in its spine and skull. A study in 2021 places the animal in a group of extinct marine lizards from the Cretaceous period known as dolichosaurs and not directly related to snakes. An alternative hypothesis, based on morphology, suggests the ancestors of snakes were related to mosasaurs—extinct aquatic reptiles from the Cretaceous—forming the clade Pythonomorpha. File:Tetrapodophis amplectus 3483.jpg|Tetrapodophis File:Eupodophis at Royal Belgian Institute of Natural Sciences, Brussels.jpg|Eupodophis descouensi File:Eupodophis descouensi Holotype.jpg|Eupodophis descouensi File:Eupodophis descouensi Holotype hind leg.jpg|Eupodophis descouensi hind leg Genetic basis of snake evolution Both fossils and phylogenetic studies demonstrate that snakes evolved from lizards, hence the question became which genetic changes led to limb loss in the snake ancestor. Limb loss is actually very common in extant reptiles and has happened dozens of times within skinks, anguids, and other lizards. In 2016, two studies reported that limb loss in snakes is associated with DNA mutations in the Zone of Polarizing Activity Regulatory Sequence (ZRS), a regulatory region of the sonic hedgehog gene which is critically required for limb development. More advanced snakes have no remnants of limbs, but basal snakes such as pythons and boas do have traces of highly reduced, vestigial hind limbs. Python embryos even have fully developed hind limb buds, but their later development is stopped by the DNA mutations in the ZRS. == Distribution ==

There are about 3,900 species of snakes, ranging as far northward as the Arctic Circle in Scandinavia and southward through Australia. There are numerous islands from which snakes are absent, such as Ireland, Iceland, and New Zealand == Biology ==

'', on an American quarter dollar Size The now extinct Titanoboa cerrejonensis was in length. By comparison, the largest extant snakes are the reticulated python, measuring about long, At the other end of the scale, the smallest extant snake is Leptotyphlops carlae, with a length of about . Most snakes are fairly small animals, approximately in length. Perception The sensory systems of snakes, particularly those of the Crotalidae family, commonly known as pit vipers, are among the most specialized in the animal kingdom. Pit vipers, which include rattlesnakes and related species, possess all the sensory organs found in other snakes, as well as additional adaptations. These include specialized infrared-sensitive receptors, known as pits, located on either side of the head between the nostrils and eyes. These pits, which resemble an additional pair of nostrils, are highly developed and allow pit vipers to detect minute temperature changes. Each pit consists of two cavities: a larger outer cavity positioned just behind and below the nostril, and a smaller inner cavity. These cavities are connected internally by a membrane containing nerves highly sensitive to thermal variations. The forward-facing pits create a combined field of detection, enabling pit vipers to distinguish objects from their surroundings and accurately judge distances. The sensitivity of these pits allows them to detect temperature differences as small as one-third of a degree Fahrenheit. Other infrared-sensitive snakes, such as those in the Boidae family, possess multiple smaller labial pits along the upper lip, just below the nostrils. Snakes rely heavily on their sense of smell to track prey. They collect particles from the air, ground, or water using their forked tongue, which are then transferred to the vomeronasal organ (also known as Jacobson's organ) in the mouth for analysis. The forked structure of the tongue provides directional information of smell which helps locate prey or predators. In aquatic species, such as the anaconda, the tongue functions efficiently underwater. When the tongue is retracted, the forked tips are pressed into the cavities of the Jacobson's organ, enabling a combined taste-smell analysis that provides the snake with detailed information about its environment. '' by G. A. Boulenger (1890), illustrating the terminology of shields on the head of a snake Until the mid-20th century, it was widely believed that snakes were unable to hear. However, snakes possess two distinct auditory systems. One system, the somatic system, involves the transmission of vibrations through ventral skin receptors to the spine. The other system involves vibrations transmitted through the snake's elongated lung to the brain via cranial nerves. Snakes exhibit high sensitivity to vibrations, allowing them to detect even subtle sounds, such as soft speech, in quiet environments. Arboreal snakes generally have better vision than burrowing species. Some snakes, such as the Asian vine snake, possess binocular vision, enabling both eyes to focus on the same point. Most snakes focus by moving the lens back and forth relative to the retina. Diurnal snakes typically have round pupils, while many nocturnal species have slit pupils. Most snakes possess three visual pigments, allowing them to perceive two primary colors in daylight. Certain species, such as the annulated sea snake and members of the genus Helicops, have regained significant color vision as an adaptation to their aquatic environments. Research suggests that the last common ancestor of all snakes had UV-sensitive vision. However, many diurnal snakes have evolved lenses that filter out UV light, likely improving contrast and sharpening their vision. Skin The skin of a snake is covered in scales. Contrary to the popular notion of snakes being slimy (because of possible confusion of snakes with worms), snakeskin has a smooth, dry texture. Most snakes use specialized belly scales to travel, allowing them to grip surfaces. The body scales may be smooth, keeled, or granular. The eyelids of a snake are transparent "spectacle" scales, also known as brille, which remain permanently closed. For a snake, the skin has been modified to its specialized form of locomotion. Between the inner layer and the outer layer lies the dermis, which contains all the pigments and cells that make up the snake's distinguishing pattern and color. The epidermis, or outer layer, is formed of a substance called keratin, which in mammals is the same basic material that forms nails, claws, and hair. The snake's epidermis of keratin provides it with the armor it needs to protect its internal organs and reduce friction as it passes over rocks. Parts of this keratin armor are rougher than others. The less restricted portion overlaps the front of the scale beneath it. Between them lies a folded back connecting material, also of keratin, also part of the epidermis. This folded back material gives as the snake undulates or eats things bigger than the circumference of its body. The shedding of scales is called ecdysis (or in normal usage, molting or sloughing). Snakes shed the complete outer layer of skin in one piece. Snake scales are not discrete, but extensions of the epidermis—hence they are not shed separately but as a complete outer layer during each molt, akin to a sock being turned inside out. Snakes have a wide diversity of skin coloration patterns which are often related to behavior, such as the tendency to have to flee from predators. Snakes that are at a high risk of predation tend to be plain, or have longitudinal stripes, providing few reference points to predators, thus allowing the snake to escape without being noticed. Plain snakes usually adopt active hunting strategies, as their pattern allows them to send little information to prey about motion. Blotched snakes usually use ambush-based strategies, likely because it helps them blend into an environment with irregularly shaped objects, like sticks or rocks. Spotted patterning can similarly help snakes to blend into their environment. The shape and number of scales on the head, back, and belly are often characteristic and used for taxonomic purposes. Scales are named mainly according to their positions on the body. In "advanced" (Caenophidian) snakes, the broad belly scales and rows of dorsal scales correspond to the vertebrae, allowing these to be counted without the need for dissection. Molting shedding its skin Molting (or "ecdysis") serves a number of purposes - it allows old, worn skin to be replaced and can be synced to mating cycles, as with other animals. Molting occurs periodically throughout the life of a snake. Before each molt, the snake regulates its diet and seeks defensible shelter. Just before shedding, the skin becomes grey and the snake's eyes turn silvery. The inner surface of the old skin liquefies, causing it to separate from the new skin beneath it. After a few days, the eyes clear and the snake reaches out of its old skin, which splits. The snake rubs its body against rough surfaces to aid in the shedding of its old skin. In many cases, the castaway skin peels backward over the body from head to tail in one piece, like taking the dust jacket off a book, revealing a new, larger, brighter layer of skin which has formed underneath. Renewal of the skin by molting supposedly increases the mass of some animals such as insects, but in the case of snakes this has been disputed. Shedding skin can release pheromones and revitalize color and patterns of the skin to increase attraction of mates. Snakes may shed four or five times a year, depending on the weather conditions, food supply, age of the snake, and other factors. One can attempt to identify the sex of a snake when the species is not distinctly sexually dimorphic by counting scales. The cloaca is probed and measured against the subcaudal scales. Counting scales determines whether a snake is a male or female, as the hemipenis of a male being probed is usually longer. In a snake's skull the brain is well protected. As brain tissues could be damaged through the palate, this protection is especially valuable. The solid and complete neurocranium of snakes is closed at the front. here, for example), consisting almost entirely of an extended ribcage. The skeleton of most snakes consists solely of the skull, hyoid, vertebral column, and ribs, though henophidian snakes retain vestiges of the pelvis and rear limbs. The hyoid is a small bone located posterior and ventral to the skull, in the 'neck' region, which serves as an attachment for the muscles of the snake's tongue, as it does in all other tetrapods. The vertebral column consists of between 200 and 400 vertebrae, or sometimes more. The body vertebrae each have two ribs articulating with them. The tail vertebrae are comparatively few in number (often less than 20% of the total) and lack ribs. The vertebrae have projections that allow for strong muscle attachment, enabling locomotion without limbs. Caudal autotomy (self-amputation of the tail), a feature found in some lizards, is absent in most snakes. In the rare cases where it does exist in snakes, caudal autotomy is intervertebral (meaning the separation of adjacent vertebrae), unlike that in lizards, which is intravertebral, i.e. the break happens along a predefined fracture plane present on a vertebra. In some snakes, most notably boas and pythons, there are vestiges of the hindlimbs in the form of a pair of pelvic spurs. These small, claw-like protrusions on each side of the cloaca are the external portion of the vestigial hindlimb skeleton, which includes the remains of an ilium and femur. Snakes are polyphyodonts with teeth that are continuously replaced. Internal organs Snakes and other non-archosaur (crocodilians, dinosaurs + birds and allies) reptiles have a three-chambered heart that controls the circulatory system via the left and right atrium, and one ventricle. Internally, the ventricle is divided into three interconnected cavities: the cavum arteriosum, the cavum pulmonale, and the cavum venosum. The cavum venosum receives deoxygenated blood from the right atrium and the cavum arteriosum receives oxygenated blood from the left atrium. Located beneath the cavum venosum is the cavum pulmonale, which pumps blood to the pulmonary trunk. The snake's heart is encased in a sac, called the pericardium, located at the bifurcation of the bronchi. The heart is able to move around, owing 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, located in fatty tissue above the heart, is responsible for the generation of immune cells in the blood. The cardiovascular system of snakes is unique for 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. In the majority of species, only one lung is functional. This lung contains a vascularized anterior portion and a posterior portion that does not function in gas exchange. The fangs of 'advanced' venomous snakes like viperids and elapids are hollow, allowing venom to be injected more effectively, and the fangs of rear-fanged snakes such as the boomslang simply have a groove on the posterior edge to channel venom into the wound. Snake venoms are often prey-specific, and their role in self-defense is secondary. According to this theory, most snakes that are labelled "nonvenomous" would be considered harmless because they either lack a venom delivery method or are incapable of delivering enough to endanger a human. The theory postulates that snakes may have evolved from a common lizard ancestor that was venomous, and also that venomous lizards like the gila monster, beaded lizard, monitor lizards, and the now-extinct mosasaurs, may have derived from this same common ancestor. They share this "venom clade" with various other saurian species. Venomous snakes are classified in two taxonomic families: • Elapids – cobras including king cobras, kraits, mambas, Australian copperheads, sea snakes, and coral snakes. • Viperids – vipers, rattlesnakes, copperheads/cottonmouths, and bushmasters. There is a third family containing the opistoglyphous (rear-fanged) snakes (as well as the majority of other snake species): • Colubrids – boomslangs, tree snakes, vine snakes, cat snakes, although not all colubrids are venomous. The hemipenes are often grooved, hooked, or spined—designed to grip the walls of the female's cloaca. Most species of snakes lay eggs which they abandon shortly after laying. However, a few species (such as the king cobra) construct nests and stay in the vicinity of the hatchlings after incubation. Several species of snake, such as the boa constrictor and green anaconda, are fully viviparous, nourishing their young through a placenta as well as a yolk sac; this is highly unusual among reptiles, and normally found in requiem sharks or placental mammals. Ritual combat between males for the females they want to mate with includes topping, a behavior exhibited by most viperids in which one male will twist around the vertically elevated fore body of its opponent and force it downward. It is common for neck-biting to occur while the snakes are entwined. Facultative parthenogenesis Parthenogenesis is a natural form of reproduction in which growth and development of embryos occur without fertilization. Agkistrodon contortrix (copperhead) and Agkistrodon piscivorus (cottonmouth) can reproduce by facultative parthenogenesis, meaning that they are capable of switching from a sexual mode of reproduction to an asexual mode. The most likely type of parthenogenesis to occur is automixis with terminal fusion, a process in which two terminal products from the same meiosis fuse to form a diploid zygote. This process leads to genome-wide homozygosity, expression of deleterious recessive alleles, and often to developmental abnormalities. Both captive-born and wild-born copperheads and cottonmouths appear to be capable of this form of parthenogenesis. Embryonic development embryo 12 day post fertilization side by side with corn snake embryo 2 days post ovo-positioning Cell division and proliferation continues until an early snake embryo develops and the typical body shape of a snake can be observed. This increase in vertebrae is due to an increase in somites during embryogenesis, leading to an increased number of vertebrae which develop. There is ample literature focusing on the limb development/lack of development in snake embryos and the gene expression associated with the different stages. In basal snakes, such as the python, embryos in early development exhibit a hind limb bud that develops with some cartilage and a cartilaginous pelvic element, however this degenerates before hatching. This presence of vestigial development suggests that some snakes are still undergoing hind limb reduction before they are eliminated. There is no evidence in basal snakes of forelimb rudiments and no examples of snake forelimb bud initiation in embryo, so little is known regarding the loss of this trait. == Behavior and life history ==

. It was brumating in a large pile of wood chips, found by this landscaper after he bulldozed the pile in late autumn 2018.|197x197px Winter dormancy In regions where winters are too cold for snakes to tolerate while remaining active, local species will enter a period of brumation. Unlike hibernation, in which the dormant mammals are actually asleep, brumating reptiles are awake but inactive. Individual snakes may brumate in burrows, under rock piles, or inside fallen trees, or large numbers of snakes may clump together in hibernacula. Feeding and diet eating an egg'' preying on a sheltopusik hooding All snakes are strictly carnivorous, preying on small animals including lizards, frogs, other snakes, small mammals, birds, eggs, fish, snails, worms, and insects. Snakes cannot bite or tear their food to pieces so must swallow their prey whole. The eating habits of a snake are largely influenced by body size; 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 a complex structure. Contrary to the popular belief that snakes can dislocate their jaws, they have an extremely flexible lower jaw, the two halves of which are not rigidly attached, and numerous other joints in the skull, which allow the snake to open its mouth wide enough to swallow prey whole, even if it is larger in diameter than the snake itself. For example, the African egg-eating snake has flexible jaws adapted for eating eggs much larger than the diameter of its head. Some snakes have a venomous bite, which they use to kill their prey before eating it. Other snakes kill their prey by constriction, while some swallow their prey when it is still alive. If a snake is disturbed after having eaten recently, it will often regurgitate its prey to be able to escape the perceived threat. When undisturbed, the digestive process is highly efficient; the snake's digestive enzymes dissolve and absorb everything but the prey's hair (or feathers) and claws, which are excreted along with waste. Hooding and spitting Hooding (expansion of the neck area) is a visual deterrent, mostly seen in cobras (elapids), and is primarily controlled by rib muscles. Hooding can be accompanied by spitting venom towards the threatening object, and producing a specialized sound; hissing. Studies on captive cobras showed that 13–22% of the body length is raised during hooding. Locomotion The lack of limbs does not impede the movement of snakes. They have developed several different modes of locomotion to deal with particular environments. Unlike the gaits of limbed animals, which form a continuum, each mode of snake locomotion is discrete and distinct from the others; transitions between modes are abrupt. Lateral undulation Lateral undulation is the sole mode of aquatic locomotion, and the most common mode of terrestrial locomotion. This mode of movement has the same net cost of transport (calories burned per meter moved) as running in lizards of the same mass. Terrestrial lateral undulation is the most common mode of terrestrial locomotion for most snake species. In this mode, the posteriorly moving waves push against contact points in the environment, such as rocks, twigs, irregularities in the soil, etc. Each of these environmental objects, in turn, generates a reaction force directed forward and towards the midline of the snake, resulting in forward thrust while the lateral components cancel out. 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. Thrust is generated by pushing their body against the water, resulting in the observed slip. In spite of overall similarities, studies show that the pattern of muscle activation is different in aquatic versus terrestrial lateral undulation, which justifies calling them separate modes. All snakes can laterally undulate forward (with backward-moving waves), but only sea snakes have been observed reversing the motion (moving backwards with forward-moving waves). Sidewinding '') sidewinding Most often employed by colubroid snakes (colubrids, elapids, and vipers) when the snake must move in an environment that lacks irregularities to push against (rendering lateral undulation impossible), such as a slick mud flat, or a sand dune, 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. The sidewinder moves forward by throwing a loop of itself and then pulling itself up by it. By lowering its head the snake gets leverage, straightening itself out and pressing itself against the ground, it brings itself forward and at an angle that leaves it ready for the next jump. The head and the loop are in effect the two feet upon which the snake walks. The snake's body, appearing roughly perpendicular to its direction, may bewilder the observer, since preconception may lead one to associate snake movement with a head that leads and a body that follows. It appears the sidewinder is going sideways - but precisely where the snake is going, where it wants to go, the head gives clear indication. The snake leaves behind a trail that looks like a series of hooks one after the next. Snakes can move backwards to retreat from an enemy, though they normally do not. This mode of locomotion overcomes the slippery nature of sand or mud by pushing off with only static portions on the body, thereby minimizing slipping. The static nature of the contact points can be shown from the tracks of a sidewinding snake, which show each belly scale imprint, without any smearing. This mode of locomotion has very low caloric cost, less than of the cost for a lizard to move the same distance. While on tree branches, snakes use several modes of locomotion depending on species and bark texture. These snakes can perform a controlled glide for hundreds of feet depending upon launch altitude and can even turn in midair. Rectilinear The slowest mode of snake locomotion is rectilinear locomotion, which is also the only one where the snake does not need to bend its body laterally, though it may do so when turning. 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. The ribs of the snake do not move in this mode of locomotion and this method is most often used by large pythons, boas, and vipers when stalking prey across open ground as the snake's movements are subtle and harder to detect by their prey in this manner. ==Interactions with humans==

Bite '', one fang in glove with a small venom stain, the other still in place Snakes do not ordinarily prey on humans. Unless startled or injured, most snakes prefer to avoid contact and will not attack humans. With the exception of large constrictors, nonvenomous snakes are not a threat to humans. The bite of a nonvenomous snake is usually harmless; their teeth are not adapted for tearing or inflicting a deep puncture wound, but rather grabbing and holding. Although the possibility of infection and tissue damage is present in the bite of a nonvenomous snake, venomous snakes present far greater hazard to humans. Documented deaths resulting from snake bites are uncommon. Nonfatal 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. Australia averages only one fatal snake bite per year. In India, 250,000 snakebites are recorded in a single year, with as many as 50,000 recorded initial deaths. The WHO estimates that on the order of 100,000 people die each year as a result of snake bites, and around three times as many amputations and other permanent disabilities are caused by snakebites annually. The health of people is seriously threatened by snakebites, especially in areas where there is a great diversity of snakes and little access to medical care such as the Amazon Rainforest region in South America. Snakebite is classified by the World Health Organization (WHO) as "other neglected conditions". Although there aren't many recorded snakebite deaths, the bites can cause serious complications and permanent impairments. Clinical studies, serum preparation, and venom extraction are among the intricate procedures involved in the manufacturing of antivenom. Snake charmers is the most common subject of snake charmings. 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 containing a snake that he seemingly charms by playing tunes with his flutelike musical instrument, to which the snake responds. The Wildlife Protection Act of 1972 in India technically prohibits snake charming on the grounds of reducing animal cruelty. Other types of snake charmers use a snake and mongoose show, where the two animals have a mock fight; however, this is not very common, as the animals may be seriously injured or killed. Snake charming as a profession is dying out in India because of competition from modern forms of entertainment and environment laws proscribing the practice. Many Indians have never seen snake charming and it is becoming a folktale of the past. Trapping The Irulas tribe of Andhra Pradesh and Tamil Nadu in India have been hunter-gatherers in the hot, dry plains forests, and have practiced the art of snake catching for generations. They have a vast knowledge of snakes in the field. They 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 of the snake-skin industry in India and protection of all snakes under the 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 antivenom, biomedical research and for other medicinal products. 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 television show hosts, like Bill Haast, Austin Stevens, Steve Irwin, and Jeff Corwin, prefer to catch them using bare hands. Consumption Consuming snake flesh and related goods is a reflection of many cultures around the world, especially in Asian nations like China, Taiwan, Thailand, Indonesia, Vietnam, and Cambodia. Because of its supposed health benefits and aphrodisiac qualities, snake meat is frequently regarded as a delicacy and ingested. It is customary to drink wine laced with snake blood in an attempt to increase virility and vigor. It is important to pay attention to and regulate the sustainable harvesting of snakes for human food, particularly in areas where snake populations are in decline as a result of habitat degradation and overexploitation. Compared with more traditional types of companion animal, snakes can be very low-maintenance pets; they require minimal space, as most common species do not exceed in length, and can be fed relatively infrequently—usually once every five to fourteen days. Certain snakes have a lifespan of more than 40 years if given proper care. Symbolism with four golden uraeus cobra figures. Gold with lapis lazuli; Valley of the Kings, Thebes (1347–37 BCE). from the mythical Longanus river in Sicily In ancient Mesopotamia, Nirah, the messenger god of Ištaran, was represented as a serpent on kudurrus, or boundary stones. Representations of two intertwined serpents are common in Sumerian art and Neo-Sumerian artwork The ouroboros was a well-known ancient Egyptian symbol of a serpent swallowing its own tail. The precursor to the ouroboros was the "Many-Faced", In a Greek myth described by Pseudo-Apollodorus in his Bibliotheca, Medusa was a Gorgon with serpents for hair whose gaze turned all those who looked at her to stone and was slain by the hero Perseus. In the Roman poet Ovid's Metamorphoses, Medusa is said to have once been a beautiful priestess of Athena, whom Athena turned into a serpent-haired monster after she was raped by the god Poseidon in Athena's temple. In another myth referenced by the Boeotian poet Hesiod and described in detail by Pseudo-Apollodorus, the hero Heracles is said to have slain the Lernaean Hydra, a multiple-headed serpent which dwelt in the swamps of Lerna. , in which the snake, through ecdysis, symbolizes healing 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. The snake is one of the 12 celestial animals of Chinese zodiac, in the Chinese calendar. Many ancient Peruvian cultures worshipped nature. They emphasized animals and often depicted snakes in their art. Religion marker from the Postclassic site of Mixco Viejo in Guatemala. This sculpture depicts Kukulkan, jaws agape, with the head of a human warrior emerging from his maw. Snakes are used in Hinduism as a part of ritual worship. In the annual Nag Panchami festival, participants worship either live cobras or images of Nāgas. Lord Shiva is depicted in most images with a snake coiled around his neck. Puranic literature includes various stories associated with snakes, for example Shesha is said to hold all the planets of the Universe on his hoods and to constantly sing the glories of Vishnu from all his mouths. Other notable snakes in Hinduism are Vasuki, Takshaka, Karkotaka, and Pingala. The term Nāga is used to refer to entities that take the form of large snakes in Hinduism and Buddhism. Snakes have been widely revered in many cultures, such as in ancient Greece where the serpent was seen as a healer. Asclepius carried a serpent wound around his wand, a symbol seen today on many ambulances. In Judaism, the snake of brass is also a symbol of healing, of one's life being saved from imminent death. In religious terms, the snake and jaguar were arguably the most important animals in ancient Mesoamerica. "In states of ecstasy, lords dance a serpent dance; great descending snakes adorn and support buildings from Chichen Itza to Tenochtitlan, and the Nahuatl word coatl meaning serpent or twin, forms part of primary deities such as Mixcoatl, Quetzalcoatl, and Coatlicue." In the Maya and Aztec calendars, the fifth day sign of the 20-day cycle was "Snake". In some parts of Christianity, the redemptive work of Jesus Christ is compared to saving one's life through beholding the Nehushtan (serpent of brass). Snake handlers use snakes as an integral part of church worship, to demonstrate their faith in divine protection. However, more commonly in Christianity, the serpent has been depicted as a representative of evil and sly plotting, as seen in the description in Genesis of a snake tempting Eve in the Garden of Eden. In Christianity and Judaism, the snake makes its infamous appearance in the first book of the Bible when a serpent appears before Adam and Eve and tempts them with the forbidden fruit from the Tree of Knowledge. The snake returns in the Book of Exodus when Moses turns his staff into a snake as a sign of God's power, and later when he makes 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." In Neo-Paganism and Wicca, the snake is seen as a symbol of wisdom and knowledge. Additionally, snakes are sometimes associated with Hecate, the Greek goddess of witchcraft. Medicine Several compounds from snake venoms are being researched as potential treatments or preventatives for pain, cancers, arthritis, stroke, heart disease, hemophilia, and hypertension, as well as to control bleeding (e.g., during surgery). == See also ==