SNAKES OF INDIA
(Dr. Girish Chandra)
Out of about 2,000 species of snakes found in the world, about 272 occur in India, which range from the 10 cm long worm snake to more than 6 meter long pythons and king cobras. They constitute approximately 10 percent of the total snake species found in the world and 80% of them are non-poisonous. The venomous snakes include only about 58 species and there are only 4 species of snakes that are dangerous to man, namely, Cobra, Krait, Russell’s viper and Saw-scaled viper.
Common Worm Snake (Typhlops braminus or Rhamphotyphlops braminus)
This snake resembles a worm, growing to a maximum length of 12 cm. It is small and worm–like with smooth shiny scales and a blunt head and tail. They are reddish brown or black and superficially look like earthworms. Worm snakes live underground in ant and termite nests. They are also found under logs, moist leaves and humus in wet forest, dry jungle and city gardens.
Indian Rock Python (Python molurus)
Indian Rock Python is found in the estuarine mangrove forest, the arid scrub jungles and the cool dense rain forests. These large, thick bodied snakes have smooth scales and a bright pattern of blotches. Like other pythons are non-venomous. They prey mainly on mice and birds, although jackals, civets, and even wild boar and deer are occasionally eaten. Snake can be 20 feet long and weigh up to 100 kilos. Usually sluggish, they have a peculiar method of locomotion in a straight line, pushing forward with its ribs. Two races, the Indian rock python and the reticulated python are common throughout India. Eggs vary in number and are laid from March-June. The eggs hatch about 58 days after being laid. The oldest python recorded in captivity was 22 year old.
Common Sand Boa (Eryx conicus)
It is a thick and round snake, 1 to 2 feet long. Its tail is very short, sharply tapering, and conical. The head is covered by small scales. It is grey with yellowish-brown blotches on the back forming a sort of irregular chain. Some specimens are of a dark-brown or blackish colour, with irregular grey stripes across the back. The young are more brilliantly coloured. The snake has a projecting snout, with the mouth placed under it. The snout is adapted for burrowing into the ground. Its belly-plates are narrow. The eyes are very small, the pupil being vertically elliptical and the iris speckled yellow. It burrows and lives in holes, which are not very deep. It is an extremely sluggish snake and is commonly seen in a snake-charmer’s basket. It lives on small mammals like mice and squirrels.
Red Sand Boa (Eryx johnii)
It is a species of snake found in Afghanistan, Pakistan, Iran, and India.
It can be identified by the presence of a mental groove, a pronounced angular ridge on the muzzle, a blunt tail and costal scales numbering over 53. Food is mainly mammals such as rats, mice and other small rodents which are killed by constriction. Ovoviviparous with up to 14 young born at a time
Common Wolf snake (Lycodon aulicus)
It is a terrestrial slender bodied snake, brown in colour with yellow cross-bars which are obvious near the head and diminishes near the tail. Found in Pakistan, Sri Lanka, India, Nepal, Myanmar, Thailand, Malaysia, Indonesia, Philippines, Seychelles and China. A small slender snake found throughout India. In the hills, it occurs at an elevation of about 2000 mts.
Barred Wolf Snake (Lycodon striatus)
It is a terrestrial slender bodied snake, generally brown in colour with many cross-bars. Found in Sri Lanka, NW India, Pakistan, USSR, S Turkmenistan, W Tajikistan, Uzbekistan, Iran, Afghanistan and Pakistan.
Banded Kukri (Oligodon arnensis)
This is a small snake with prominent cross bands on its body. Found all over India and up to an elevation of 200 mts. in the eastern Himalaya.
Striped Keelback (Amaphiesma stolata)
A small to medium-sized snake, this is closely related to and resembles the water snakes and is found all over India and up to an elevation of 2,000 mts. in the hills.
Green Keelback (Macropisthodon plumbicolor)
A medium-sized keel-scaled snake found in the forested regions of India up to an elevation of 1,500 mts.
Checkered Keelback Watersnake (Xenochropis (=Natrix) piscator)
A medium-sized keeled snake found all over India up to an elevation of about 3,000 mts. Brownish coloured with chess board arrangement of spots, grows to a length of one metre. It has two tear-marks just below the eyes. Shows extreme aggression and readily bites anything but the bite is completely harmless. It feeds mainly on small fishes and water frogs. Average length is more than 4 ft. Found near fresh water lakes and paddy fields in Afghanistan, Pakistan, Sri Lanka, India, Burma, Thailand, Laos, Vietnam, West Malaysia, China, Taiwan and Indonesia.
Olive Keel-back (Atretium schistosum)
It is a species of snake found in Sri Lanka, India and Nepal. It can be distinguished by a single inter-nasal, 19 costals at mid body and 8 to 9 supra–labials.
It Lives in water or among the surrounding vegetation. Largely diurnal and feeds mainly on frog, fish and crabs. A small to medium-sized snake found in central and peninsular India up to an elevation about 1,000 mts.
Trinket Snake (Elaphe helena)
It is a terrestrial snake. It feeds on frogs, toads, etc. A medium-sized, slender snake found all over India up to an elevation of about 4,000 mts. in the Himalayas.
Rat Snake (Ptyas mucosus)
It is a terrestrial snake. The Rat snake can grow up to 11 feet in length. Colours varied due to different climatic conditions and change in habitats. The Rat snake has black tear marks just below the labial. They have numerous cross bars near the tail. It is voracious feeder of rats and mice and frogs. Their size and colour are similar to the cobras. Rat snakes are found wherever rats and frogs/toads are prevalent. So, of course, they are often found in rice fields and in human habitation. The colour varies from jet black in the hills to yellowish or brown. The female lays about 8 to 16 eggs and the young start their diet on frogs.
Fasciolated Rat snake or Banded Racer (Argyrogena (=Coluber) fasciolatus)
This harmless, olive-brown snake is beautifully ornamented with black and white cross bars that gradually disappear along the mid body. This can be plucky and aggressive if irritated. It feeds on small mammals and amphibians. It is found throughout India, although it is fairly common southwest India. Little is known about breeding habits. Oviparous, It is found in India, Sri Lanka, Pakistan, Nepal and Bangladesh. Average size is over 1 metre. Anal 2, supra–labials 8, 3rd divided, 4th and 5th touching eye, 5th and 6th highest touching temporal.
Bronze-back Tree Snake (Dendrelaphis tristis; D. pictus)
It is a species of tree-snakes found in Sri Lanka, India, Pakistan and Nepal. It is a long slender snake with a bronze coloured line running down its back. It has a pointed head. It feeds mainly on tree geckos, frogs and small birds. It gracefully moves through thick vegetation. It broadens it neck to show white and bluish interscale coloration when disturbed. This harmless snake prefers the tree tops to life on the ground. It is perfectly camouflaged among the leaves because of its uniform ruddy brown skin. It springs on its prey and feeds largely on lizards and tree frogs and occasionally on birds. This oviparous snake lays its eggs between September-February. The 6-7 eggs in a clutch hatch 4-6 weeks after egg-laying and the gestation period is 4-6 months.
Flying snake or Golden tree snake (Chryopelea Ornata)
This beautiful and harmless black snake has narrow pale greenish-yellow cross bars. It prefers trees but also frequently spotted in the grass and on low bushes. It feeds largely on geckos and other lizards. The 6-12 eggs are laid in May, while hatchlings have been recorded in June. They prefer to live on large trees and appear to glide for some distance.
Royal Snake (Spalerosophis diadema)
A medium to large-sized snake found in the drier tracts of Rajasthan, Punjab, Haryana, Uttar Pradesh, Jammu hills and Himachal Pradesh up to an elevation of 2,000 mts.
Green Wine Snake or Green whip snake (Ahaetulla (=Dryophis) nasuta)
A medium to large-sized snake found all over India, except in the northwest and parts of the Ganges plain. They may occur at elevation of about 2,500 mts. preferring low bushes and trees. Parrot green in colour with faint yellow and blue lines. It moves very fast from branch to branch on trees and bushes.
Common Cat Snake (Boiga trigonata)
A small to medium-sized snake found all over India up to an elevation of 3000 mts. in the Himalayas. They are nocturnal in habit and prefer to spend the daylight hours in a cool place.
Dog-Faced Watersnake (Cerebrus rhynchops)
A medium-sized snake found in the coastal tracts. They live in muddy and rocky areas in estuaries, mangrove swamps, salt pans and deserted areas. It is grey with black marking on the back, and two stripes running behind each eye. It is a rough, dull snake, one of the six species of “rear fanged” swamp snakes in India. On land this snake is one of the “side winders”. In rapid movement, it does a kind of sideways leap. All brackish water snakes give birth to about 10 to 30 young at a time.
Indian Egg eater (Elachistodon westermanni)
It is a rare species of egg-eating snake found in Bangladesh, India, and Nepal. Also called the Westermann’s snake, it belongs to the monotypic genus Elachistodon. Recent discoveries of the species from Maharashtra and Gujarat suggest that the species may be more widespread. The snake has special adaptations with vertebral hypapophysis, a projection of the backbone into the oesophagus that helps in cracking eggs. After an egg has been swallowed whole, these projections hold it and then puncture and crack the shell. The contents are then be swallowed and the collapsed shell is regurgitated. Egg-eating snakes are mainly arboreal, enabling them to access eggs in birds’ nests. Generally less than 1 m in length, it is a slender grey-brown snake with two V-shaped markings on the top of its head and a regular pattern of dark markings along its back.
POISONOUS SNAKES OF INDIA
There are three types of venomous snakes: Opisthoglyph are the rear-fanged snakes, the fangs with a ‘groove’ that venom flows down. The Boomslang (Dispholidus typus) and the Twig snake (Thelotornis kirtlandi) are examples. Proteroglyphs are the fixed front fang snakes that have non-movable front fangs. Examples of this type of snake are the cobras (Naja), kraits (Bungarus), mambas (Dendroaspis), and coral (Micrurus) snakes. Solenoglyph have movable front fangs which fold back into the mouth until they are needed. Examples include rattlesnakes (Crotalus), eyelash vipers (Bothriechis), and copperheads (Agkistrodon).
King Cobra (Ophiophagus hannah)
The third largest snake in India, the king cobra is also one of the most courageous, poisonous and aggressive snakes. Their hood is relatively less inflatable than that of the Indian Cobra. The body is blackish brown with lighter bands running throughout its entire length. King cobra has a voracious appetite and their staple diet is snakes but they also eat lizards and rats. Mating has been observed in March, with copulation lasting for about an hour. The eggs are laid 5-6 weeks after mating. A maximum of 51 eggs have been recorded. King cobras can reach 18 feet (5.5 meters) in length, making them the longest of all venomous snakes. When confronted, they can raise up to one-third of their bodies straight off the ground and still move forward to attack. They will also flare out their iconic hoods and emit a bone-chilling hiss that sounds almost like a growling dog. Their venom is not the most potent among venomous snakes, but the amount of neurotoxin they can deliver in a single bite is up to 7 ml that is enough to kill 20 people or an elephant.
Indian Cobra (Naja naja)
One of the most poisonous snakes found in India, the cobra has the most distinctive features as its hood. There are three races mainly the Indian Spectacled Cobra (Naja naja naja), the mono-ocellate cobra (Naja naja kaouthia) and the black cobra. Cobra feed principally on rats, frogs and toads, but can also take in lizards and snakes and also earthworm, ants, cockroaches and eggs. Mating occurs in January and 12-22 eggs are laid in April-May, which hatch within 45 to 69 days.
Bamboo pit viper (Trimersurus gramineus)
All vipers give birth to live young which hatch from eggs inside the mother’s uterus. They can be distinguished from all other groups of snakes by the presence of the loreal pit (heat sensitive pit enabling the snake to locate and capture its prey). This beautiful but poisonous snake has a glossy green back and yellowish white bottom. It is usually sluggish during the day but when provoked it anchors itself firmly by its prehensile tail with an open mouth. It prefers hilly forests and bamboo forests.
Russell’s viper (Daboia =Vipera russelli)
This is a medium to large-sized snake with a characteristic bright pattern on its body. Found all over India, both in the plains and hills up to an elevation of about 3,000 mts. This snake grows to a maximum length of 166 cm. The average length is about 120 cm on the mainland, although island populations do not attain this size. The head is flattened, triangular and distinct from the neck. The snout is blunt, rounded and raised. The nostrils are large, in the middle of a large, single nasal scale. The lower edge of the nasal touches the naso–rostral. The supra–nasal has a strong crescent shape and separates the nasal from the naso–rostral on the anterior. The rostral is as broad as it is high. The body is stout, the cross-section of which is rounded to cylindrical. The dorsal scales are strongly keeled; only the lower row is smooth. It feeds primarily on rodents, especially murid species. However, they will eat just about anything, including rats, mice shrews, squirrels, domestic cats, land crabs, scorpions and other arthropods. Adults are reported to be persistently slow and sluggish unless pushed beyond a certain limit, after which they becomes fierce and aggressive. Juveniles, on the other hand, are generally more active and will bite with minimal provocation.
Saw-scaled Viper (Echis carinatus)
A small-sized snake found all over India, usually in the plains. They may occur in areas as high as 2,000 mts. in the north–western Himalayas. Size ranges between 38 and 80 cm in length, but usually no more than 60 cm. Head distinct from neck, snout very short and rounded. The nostril between three shields and head covered with small keeled scales, among which an enlarged supra ocular is sometimes present. They move about mainly by side winding: a method at which they are considerably proficient and alarmingly quick. It feeds on rodents, lizards, frogs, and a variety of arthropods, such as scorpions, centipedes and large insects. The population in India is ovoviviparous. In northern India, mating takes place in the winter with live young being born from April through August.
Himalayan pit viper (Gloydius himalayanus)
It is a venomous pit viper species found along the southern slopes of the Himalayas in Pakistan, India and Nepal. Medium-sized snake, with distinct elongated head covered with large symmetrical scales; a distinct pit between eye and nostril. Dorsum light brown, gray to dark brown. A median series of dark brown blotches, alternating with lateral row of spots. A broad dark band from eye to the angle of mouth. Supralabials light with dark mottling. Ventrum light gray with dark clouding and fine spotting. This snake frequents rocky wooded hill sides, where it lives in caverns and crevices among rocks, hibernates in winter from October to April. Basks in bright sunny winter days, habitually sluggish. Feeds mainly on skinks and other mountain lizards.
Common Krait (Bungarus caeruleus)
Found almost all over India, they are nocturnal in habit. Commonly found in northeast India, Bihar, Orissa, Madhya Pradesh, Andhra Pradesh and Uttar Pradesh up to an elevation of 1500 mts. It is easily identified by its triangular body cross-section and the marked vertebral ridge consisting of enlarged hexagonal vertebral shields along the middle of the dorsal side. The head is not distinct from neck. The eye is black. It has arrow-head like yellow markings on its black head and has yellow lips, lore, chin and throat.
Banded Krait or (Bungarus fasciatus)
They are medium to large-sized snake with prominent yellow and black bands on the body. The banded krait has been recorded to grow up to a length of 2 metres in M.P., Bihar, Orissa, U.P. and Assam. Sometimes there is a black spot on the head. It feeds on other snakes.
Sleder Coral Snake (Callophis melanurus)
A small slender snake found in most parts of the country except parts of central and northeast India, Bihar, Orissa, Madhya pradesh, Andhra Pradesh and Uttar Pradesh up to an Elevation of 1500 mts. A small and slender snake that has uniform pale brown body colouration. This snake can be identified by its non-evident neck, blunt snout, widely spaced nostrils which nearly are as wide apart as the eyes and small Supra-ocular compared to the Frontal. Its head is mottled and dotted with black from which its specie name has been derived. The tip of its tail may also have a similar colouration and it could serve to act as a decoy. Some specimens have a brown colouration. Little is known about its behaviour. It appears to be inactive and sluggish by day.
Hook-nosed Sea Snake or Beaked sea snake (Enhydrina schistosa)
This is a medium-sized snake having a flattened body and tail. Found along the coast and coastal islands. They are seasonally found in the deep sea though they prefer coastal areas. These snakes are generally found in the coast and coastal islands of India. They are amongst the most common of the 20 kinds of sea snakes found in that region. They are active both during the day and at night. They are able to dive up to 100 m and stay underwater for a maximum of five hours before resurfacing. Sea snakes are equipped with glands to eliminate excess salt. They are venomous, but not aggressive and are thus handled by the fishermen without fear, though they are thrown back into the sea upon sight. The venom of this snake is rated four to eight times as toxic as cobra venom. About 1.5 milligrams of its venom is estimated to be lethal. The principal food is fish.
Dwarf Sea snake (Hydrophis caerulescens)
Scales on thickest part of the body are quadrangular or hexagonal in shape. There are 14-18 maxillary teeth behind front fangs. Ventrals 253-334 and distinct throughout, though not twice as large as the adjacent body scales. Colour bluish grey above, whitish below, with 40-60 broad bands. This snake ooccurs in Indian Ocean, Coasts of China, South China Sea and Australia.
(copyright Dr. Girish Chandra)