snake-necked turtle: see side-necked turtle.

snake-bird: see darter.

snake worship. The snake has been variously adored as a regenerative power, as a god of evil, as a god of good, as Christ (by the Gnostics), as a phallic deity, as a solar deity, and as a god of death. It has also served as the symbol of Satan and many deities, including Apollo and the Egyptian god Ra. Snake worship found expression in both the Toltec and Aztec periods of prehistoric Mexican civilization. In Aztec mythology a half-divine, half-human being descended to earth for a while as the great teacher of mankind; the Aztecs called him the "feathered serpent," the incarnation of the serpent sun. In Egypt, according to one authority, each temple had a reserved area where snakes were kept. In Greek religion the snake was frequently considered divine. Among the Greek Dionysian cults it signified wisdom and was a symbol of fertility. The Greek god most closely associated with snake worship is Apollo; the original name of Apollo's temple at Delphi was Pytho, after the snake Python. In Rome during the period of the empire, a sacred snake was kept within the city and was attended by the vestal virgins; it was believed that if the snake refused to accept food from the hand of one of its attendants, the attendant was no longer a virgin, and she was promptly killed. The ancient Mesopotamians and Semites believed that the snake was immortal because it shed its skin and appeared in a fresh guise. The Indians, Burmese, and Siamese worshiped the snake as a demon who also had good aspects. Primitive Hindu snake cults were incorporated into the worship of Krishna and eventually into the worship of Vishnu. Buddhist legends relate that Buddha was given the true Buddhism by the "king of the serpents" (often seen as the cobra), and Buddhists also revere the regenerative powers the snake exhibits. In China the serpent, in the form of the dragon, figures as a fierce but protective divinity. Snake charming, not to be confused with snake worship, is the art of fascinating, capturing, and controlling serpents.

snake, common name for an elongated, limbless reptile of the order Squamata, which also includes the lizards. Most snakes live on the ground, but some are burrowers, arboreal, or aquatic; one group is exclusively marine. In temperate climates they hibernate. They are generally solitary in their habits, although they may congregate in places offering food or shelter, and large numbers may hibernate together. Snakes range in length from about 4 in. (10 cm) to over 30 ft (9 m). Most are protectively colored.

Characteristics

Anatomy

Snakes constitute the suborder Serpentes (or Ophidia). In most snakes limbs are entirely lacking, but a few have traces of hind limbs. The skin, which is covered with horny scales, is shed, usually several times a year. The extremely long, narrow body is associated with distinctive internal features. The number of vertebrae is much larger than in most vertebrates, paired internal organs are arranged linearly rather than side by side, and only one lung is developed, except in members of the boa family, which have two lungs. The jaws of snakes are loosely jointed and extremely flexible. The pointed, backward-curved teeth are fused to the supporting bones of the head. There are no ears or movable eyelids. Snakes have good vision. They do not hear airborne sound waves, but can perceive low-frequency vibrations (100-700 Hz) transmitted from the ground to the bones of the skull. A chemosensory organ opens into the roof of the mouth; it receives stimuli from the forked tongue that constantly tastes the surroundings as the animal moves along. Snakes have no larynx or vocal chords, but are capable of producing a hissing sound.

Locomotion and Limblessness

A snake moves by means of muscular contraction, which can produce several types of locomotion, the commonest types being undulation and straight-line movement. Straight-line movement is aided by the ventral plates, elongated scales on the abdomen that overlap with their open ends pointing toward the tail. These plates can be moved forward by means of muscles attached to the ribs.

It is believed that snakes are descended from lizards, but how and why they evolved toward limblessness is uncertain. Some paleontologists have held that limblessness was an evolutionary advantage in the dense vegetation that formed the early environment of snakes, or that it developed to facilitate burrowing habits, but others believe that the earliest snakes evolved in a marine environment and are descended from marine lizards. Support for the latter view comes from recent discovery of the most primitive snake now known, a fossil specimen with two short but well-developed hind legs found in marine sediments in Israel. It lived in a shallow sea 95 million years ago.

Predation

Small snakes feed on insects and larger ones on proportionately larger animals. Their teeth are designed for catching and holding prey, but not for chewing. The construction of the jaws, the ribs, and the expandable skin enable them to swallow very large prey whole. Some snakes capture animals by pinning them to the ground; some—the constrictors—crush them by wrapping their bodies around them and squeezing; still others—the venomous snakes—inject poison into their victims. The poison, or venom, is produced by modified salivary glands from which it passes through either a groove or a hollow bore in the fangs, the enlarged, specialized teeth found in venomous snakes. A snake may bite a person when threatened or alarmed; if the snake is venomous the bite can sometimes prove fatal (see snakebite). Only by familiarity with the appearance of particular species, or by examination of the fangs, can the venomous snakes be distinguished from the harmless ones.

Reproduction

Fertilization is internal in snakes; as in lizards, the males have paired copulatory organs, either of which may be used in mating. Females of some species can store sperm for several years to insure future fertilization. In most species the female lays eggs; in some the eggs are incubated and hatched within the mother's body; in a few there is true viviparity, or live birth, with the young nourished by means of a placenta rather than an egg. Some egg-laying snakes brood the eggs, but there is no parental care of the young.

Types of Snakes

The approximately 2,700 snake species, of which about four fifths are nonvenomous, are distributed throughout the temperate and tropical zones of the world (except in New Zealand, Ireland, and some isolated oceanic islands) and are found in greatest profusion in the tropics. About two thirds of all snake species belong to the family Colubridae; most of these are nonvenomous. Among the harmless colubrid snakes of North America are the garter snakes (including the ribbon snake), the water snakes, the green, or grass, snakes, the black snakes, the racers, the king snakes (including the milk snake), and the bull, hognose, and rat snakes. The family Boidae (boas and pythons) includes the world's largest snakes, the South American anaconda and the Asian reticulated python, as well as the smaller boa constrictor and the tree and sand boas.

Most poisonous New World snakes belong to the pit viper family; these include the copperhead, water moccasin, rattlesnake, fer-de-lance, and bushmaster. Venomous Old World snakes are the true vipers, including the adder and the asp, and members of the cobra family, including the mamba of Africa and the krait of Asia. The poisonous coral snakes of the New World also belong to this family. The venomous sea snakes inhabit tropical oceans.

Importance

Snakes are of major importance as pest controllers because of their extensive predation on destructive mammals such as rats and mice. Some, like the sea snakes and pythons, are highly regarded as food in Asia but, although most are probably edible, snakes are not widely used for meat. The skin is often used for belts, bags, and shoes. Venom is removed from snakes for use in treating certain diseases and to make antivenin for snakebites.

See also snake worship.

Classification

Snakes are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, suborder Serpentes.

sea snake, name for any of the venomous marine snakes of the family Hydrophidae, found in tropical waters of the Indian and Pacific oceans. The sea snake's body is flattened laterally and its oarlike tail is used as a scull. A specialized lung and nostrils with valves enable it to remain submerged for periods of up to 8 hr. Most species are dark above and lighter below, or ringed with black and grayish green. They feed on small fish and are preyed upon by sea birds, sharks, and larger fish. Their potent venom quickly immobilizes their prey; however, they are not aggressive and rarely strike at humans when caught. Most sea snakes are completely marine and lack the enlarged ventral scales that enable land snakes to grip the ground. These snakes bear live young at sea. Most inhabit the shallow waters of the Indonesian region, but the common sea snake, Pelamis platurus, ranges from Madagascar E to Mexico and is sometimes found swarming by the thousands in open ocean. It is black or dark brown above and yellow below and grows up to 3 ft (90 cm) long. A few sea snake species leave the water to lay eggs on coral reefs. These snakes have ventral plates like those of land snakes. Sea snakes are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Hydrophidae.

rat snake: see black snake.

milk snake: see king snake.

king snake, name for a number of species of the genus Lampropeltis, nonvenomous, egg-laying, constricting snakes of North America which show much variation in color and markings. The common king snake, or chain snake (Lampropeltis getulus), of the E United States is usually about 3 to 5 ft (90-150 cm) long and black or brown with yellow and white rings or bands that form a chainlike pattern. It eats rodents, birds, and snakes. It is immune to the venom of the rattlesnake and the copperhead, which it kills by constriction. The scarlet king snake (L. doliata) has a pattern of black, red, and yellow bands similar to that of the unrelated coral snake. Other less brightly marked varieties of the same species are called milk snakes, because they are reputed by legend to milk cows. King snakes are valuable destroyers of rodents. They are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Colubridae.

indigo snake: see racer.

harlequin snake: see coral snake.

glass snake, common name for the snakelike legless lizards of the genus Ophisaurus found in the S and central United States and in Eurasia. The shiny, scaled body is gray or greenish brown, sometimes striped above and whitish below. The American species, Ophisaurus ventralis, is 2 to 3 ft (60-90 cm) long; two thirds of the length is tail. The tail of a glass snake breaks easily from the body, either whole or in pieces, if struck; the lizard regenerates a new, usually shorter, tail without a real backbone. Like other lizards, and unlike snakes, the glass snake has eyelids and ear openings. Its tongue is broad. It feeds mostly on insects, worms, and slugs. A burrower, it lives in fields and meadows and seldom appears above ground in daylight. Glass snakes are classifed in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Anguidae.

garter snake, harmless snake of the genus Thamnophis, abundant from Canada to Central America. There are many common species; members of most species are about 2 ft (60 cm) long. Most garter snakes are striped or banded lengthwise, and some are spotted between the stripes. Less aquatic as a group than the related water snakes, they are found near water in dry country and are widely distributed in moist regions. They prey on cold-blooded animals, chiefly frogs, toads, small fish, and earthworms. Females bear live young in large litters, sometimes numbering 50 or more. The common garter snake of the NE United States, Thamnophis sirtalis, varies in color and pattern but is usually blackish or brownish with three yellow stripes. The ribbon snake, T. sauritus, is a very slender garter snake that prefers wet places. Garter snakes are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Colubridae.

coral snake, name for poisonous New World snakes of the same family as the Old World cobras. About 30 species inhabit Mexico, Central America, and N South America; two are found in the United States. The Eastern coral snake (Micrurus fulvius), or harlequin snake, is found in the SE United States and N Mexico. It is a burrowing snake with a small, blunt head and a cylindrical body, averaging 21/2 ft (75 cm) in length. The body is ringed with bands of black, red, and yellow; the tail has yellow and black rings only. The Sonoran, or Western, coral snake (Micruroides euryxanthus) is a rather rare species found in the SW United States and NW Mexico. It is about 18 in. (45 cm) long and has much broader bands of yellow than those of the Eastern species. Coral snakes can be distinguished from a number of similarly colored harmless snakes by the fact that they are the only ones with red bands touching yellow ones. The venom of coral snakes, like that of cobras, acts on the nervous system and causes paralysis; the mortality rate among humans who are bitten is high. However, coral snakes are infrequently encountered because of their burrowing habits, and they seldom bite unless handled. They feed on other snakes and on lizards. Coral snakes are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Elapidae.

coachwhip snake: see racer.

chain snake: see king snake.

black snake, name for several snakes, not all closely related, that are black in color. In the United States the name is applied chiefly to the black racer and to the black rat snake (Elaphe obsoleta), both partly arboreal in their habits. The black rat snake, also called pilot black snake and mountain black snake, is found in the NE United States. Like other rat snakes (Elaphe species), it is a constrictor and a valuable destroyer of rats and mice. It has shiny, slightly keeled scales and reaches a length of 8 ft (2.4 m). The poisonous Australian black snake belongs to the cobra family and has a hood. The North American black snakes are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Colubridae.

Snake, river, 1,038 mi (1,670 km) long, NW United States, the chief tributary of the Columbia; once called the Lewis River. The Snake rises in NW Wyoming, in Yellowstone National Park, flows through Jackson Lake in Grand Teton National Park, then S and W into Idaho and northwest to its junction with the Henrys Fork River. The combined stream runs southwest, then northwest, crossing southern Idaho through the Snake River plain; there are several notable falls. The Snake makes a bend into Oregon and turns north to form the Idaho-Oregon and Idaho-Washington lines (receiving several tributaries, including the Boise and Salmon rivers), then turns at Lewiston, Idaho (at the mouth of the Clearwater River), and flows generally west to join the Columbia River near Pasco, Wash. Hell's Canyon is the greatest of the Snake's many gorges and one of the deepest in the world. Extending c.125 mi (200 km) N along the Oregon-Idaho line, it reaches a maximum depth of c.7,900 ft (2,410 m).

The Snake was explored by the Lewis and Clark expedition (1803-6) and was of major importance in U.S. expansion into the Pacific Northwest. The river is a major source of electricity, having numerous hydroelectric power plants. The upper and middle courses of the Snake and its tributaries are much used for irrigation by private projects (one of the most notable being at Twin Falls) and by projects of the U.S. Bureau of Reclamation, including the Minidoka project, the Boise project, the Palisades project, and the Owyhee project. Four navigation and hydroelectric power projects along the lower Snake provide slack water navigation from the mouth of the Snake 140 mi (225 km) upstream to Lewiston, Idaho. The projects are linked with the navigation system on the Columbia River. The late 1990s brought efforts to restore portions of the river by removing gravel and establishing new islands.

Any of about 200 snake species of about 38 genera, especially Natrix and Nerodia, classified within the family Colubridae, found worldwide except in South America. Most species have a stout body with dark blotches or streaks and ridged scales. Some are similar in appearance to venomous species. They kill fishes and amphibians with a nonvenomous bite. The New World species live in or near water and bear live young; European species are less water-dependent and lay eggs. In defense they inflate the head, strike, and release a foul secretion. Average length is about 3 ft (1 m); some Old World species reach 6 ft (1.8 m).

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Region, south and southwestern U.S. It is characterized by a warm climate, rapid population growth since 1970, and relatively conservative voting patterns. Comprising 15 states, it extends from Virginia and Florida in the southeast through Nevada in the southwest, and includes southern California.

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Any member of about 19 reptile families (suborder Serpentes, order Squamata) that has no limbs, voice, external ears, or eyelids, only one functional lung, and a long, slender body. About 2,900 snake species are known to exist, most living in the tropics. Their skin is covered with scales. They have good eyesight, and they continually taste the surrounding air with their tongues. Though they lack any voice, they are capable of hissing. Most live on the ground, but some are arboreal or aquatic, and some are burrowers. They move by muscular contraction, aided by elongated scales on their abdomen. They focus 70percnt of their mostly solitary existence on tracking, capturing, and digesting their living prey. The construction of their jaws and bodies enables them to swallow large prey whole. Because they are ectotherms (cold-blooded), a single meal can often sustain them for weeks. Mating and laying eggs or bearing live young are brief seasonal activities. About one-tenth of snake species are venomous; some can kill humans with their bite. Others kill their prey by constriction or simply ingesting. Species range from less than 5 in. (12 cm) to over 30 ft (9 m) long. Snakes grow continuously throughout their lives, shedding their outgrown skin at each growth increment. They are found worldwide, but few species are found on islands or in regions with long winters.

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Any of some 50 species (family Hydrophiidae) of venomous, marine snakes with an oarlike tail and flattened body. Most are found along coasts and in estuaries of Australia and Asia, sometimes basking on the surface in a large group, though the yellow-bellied, or pelagic, sea snake ranges throughout the Pacific. The nostrils, usually on top of the snout, have valvelike closings. The body of several species is much thicker than the head and neck. Most species are 3–4 ft (1–1.2 m) long; Laticauda semifasciata, a Japanese delicacy, may be twice as long. Though generally slow to strike, their venom may be lethal.

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Any of 40–55 snake species in the genus Elaphe (family Colubridae) and similar forms, found in woodlands and barnyards in North America, Europe, and Asia. Nonvenomous, they kill rats and mice by constriction, and also eat eggs and poultry. Some hunt birds in trees. These egg-laying snakes are normally slow and docile, but in self-defense they vibrate the tail, discharge a foul liquid, and strike from an upreared position. The black rat, or pilot black, snake (E. obsoleta obsoleta) of the eastern U.S. may exceed 8 ft (2.5 m).

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Any of seven species of snake (genus Lampropeltis, family Colubridae) found in numerous habitats from southeastern Canada to Ecuador. They kill by constriction; named for their practice of eating other snakes, they also take small mammals, amphibians, birds, and birds' eggs. They are mainly terrestrial and relatively slow-moving. Strikingly marked and smooth-scaled, they have a small head and are usually less than 4 ft (1.2 m) long, though some specimens may approach 7 ft (2 m). The common king snake, found throughout the U.S. and in northern Mexico, is usually black or dark brown, variously blotched, ringed, or speckled with yellow or white.

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Nonvenomous snake (Drymarchon corais, family Colubridae) found from the southeastern U.S. to Brazil. The largest snake in the U.S., it has a record length of 9.2 ft (2.8 m). In the U.S. it is blue-black; southward it may have brown foreparts, and in the tropics it is often called brown snake. It kills small vertebrates, including venomous snakes, by crushing with its jaws and the weight of its coils, but is not a constrictor. In defense it hisses and vibrates its tail but rarely strikes. It may share a burrow with a gopher tortoise, for which it is often called gopher snake. It has been listed as an endangered species since the 1970s.

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Any of three or four species (genus Heterodon, family Colubridae) of harmless North American snakes named for their upturned snout, which is used for digging. When threatened, they flatten the head and neck, then strike with a loud hiss, but rarely bite. If their bluff fails, they roll over, writhing, and then act dead, with mouth open and tongue lolling. They eat chiefly toads and frogs. Heavy-bodied and blotchy, they are usually about 24 in. (60 cm) long. Though not adders, they are sometimes called puff adders or blow snakes.

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Any of more than a dozen species of snakes (genus Thamnophis, family Colubridae) with a striped pattern that resembles a garter: usually one or three longitudinal yellow or red stripes, with checkered blotches between. Forms in which the stripes are obscure or lacking are called grass snakes. Found in gardens and vacant lots, garters are among the most common snakes from Canada to Central America. They are small (usually less than 24 in., or 60 cm, long) and harmless, though some will strike if provoked. They eat insects, earthworms, and amphibians.

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Any of about 90 species of strongly patterned burrowing elapids. “True” forms are limited to the New World, chiefly the tropics, but similar species live in Asia and Africa. Secretive and docile, coral snakes rarely bite when handled, but the venom of some can kill a person. Most prey on other snakes. More than 50 species in the largest genus, Micrurus, range from the southern U.S. to Argentina. They are ringed with red, black, and yellow or white. The eastern coral snake, or harlequin snake (Micrurus fulvius), ranges from North Carolina and Missouri in the U.S. to northeastern Mexico and is about 30 in. (76 cm) long, with wide bands of red and black separated by yellow. The rhyme “Red on yellow, dangerous fellow” distinguishes it from similarly coloured but harmless species.

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Any of several species of all-black or nearly all-black snakes. Australian black snakes are in the elapid genus Pseudeschis. The black snake of Australian wetlands (P. porphyriacus) grows to an average length of 5 ft (1.5 m). If annoyed, it expands its neck, cobra fashion. Its venom is rarely fatal. Other Australian black snakes are the mulga snake (P. australis) and the spotted black snake (P. guttatus). North American black snakes include two species in the family Colubridae: the black racer and the pilot black snake (Elaphe obsoleta).

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Group of closely related North American Indian peoples living in the Great Basin region of the U.S. Their language belongs to the Numic group of the Uto-Aztecan family. The Shoshone are usually divided into four groups: Western (unmounted) Shoshone, centred in eastern Nevada; Northern (mounted) Shoshone of northwestern Utah and southern Idaho; Wind River Shoshone in western Wyoming; and the Comanche, a relatively recent division related to the Wind River peoples, in western Texas. The Western Shoshone traditionally subsisted through hunting and gathering. The Northern Shoshone and Wind River Shoshone probably acquired horses by 1680 and adopted much of Plains Indian culture; they hunted buffalo, used tepees and skin clothing, and warred with other tribes. The Shoshone are closely related to the Ute, Paiute, Gosiute, and Bannock. Early 21st-century population estimates indicated some 19,000 individuals of Comanche descent and an additional 22,000 individuals of Western, Northern, or Wind River Shoshone descent.

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