Venomous Snakes of Nepal

V enomous S nakes of N epal. A photographic guide.

What is a snake?. 1. Which other animals look similar to snakes?.

Venomous Snakes of Nepal. Vipers and pit vipers (family Viperidae) Daboia russelii Gloydius himalayanus Himalayophis tibetanus Ovophis monticola Protobothrops sp. Trimeresurus cf. albolabris Trimeresurus septentrionalis Other venomous snakes Rhabdophis subminiatus Management of snake bite Introduction Clinical features of snake bite Cobra and krait bites Viper bites First aid Management at the health centre Immediate management Indications for antivenom injection Dose of antivenom Prevention of snake bite.

Fig. 1 . Spectacled Cobra ( Naja naja ). What is a snake? Snakes are limbless reptiles having an elongated body covered with scales which are arranged in rows. The form, structure and arrangement of these body scales are important for snake species identification. Snakes are different from birds and mammals in many ways. They are vertebrate animals too (with an inner skeleton), but birds and mammals are warm-blooded animals which can maintain their body temperature stable despite changing temperatures in the environment. However, snakes are cold-blooded animals and under normal circumstances they have to regulate their body temperature by choosing appropriate places in their environment (e.g., by sun bathing or hiding in holes), so they are very sensitive to weather and climatic changes and other ecological or environmental conditions. Which other animals look similar to snakes? Superficially, some snakes look similar to certain fishes, e.g., eels. However, fishes have gills and typically use these for breathing, whereas snakes breathe via lungs throughout their life. Also, many eels move in the water with the help of fins (which snakes do not have), and they do not have scales on the body like snakes. Earthworms are sometimes confused with snakes but they have no interior skeleton of bones and no protective scales covering the body; instead they have rings on their body which snakes do not have. So-called worm or blind snakes that often are of similar size and shape as earthworms do 1.

Venomous Snakes of Nepal. Fig. 2 . Common/Brahminy Worm Snake ( Ramphotyphlops braminus ) from Kapilvastu District, Nepal. have these scales (just very small and shiny ones, see Fig. 2), and even poorly developed eyes visible as dark spots on the head. Limbless amphibians also have distinct rings on their bodies, but they have a bony skeleton, and visible eyes on the head. Unlike frogs and salamanders, limbless amphibians have body scales that are embedded in the skin along the ring grooves. From lizards, snakes differ in various ways. Snakes do not have legs, but lizards typically have legs. Snakes have no external ears, but lizards have external ear openings that are usually well visible. Most lizards, including those species that have a snake-like body without limbs, have moveable eyelids so they can close their eyes. In snakes, there are no moveable eyelids. Instead, the eye is covered by a transparent disc-like scale for protection. The same type of eye without eyelid is also seen in certain lizards like the common house gecko. Finally, snakes have tongues with forked tips. As they use their tongue to detect odours in their environment, having a forked tongue allows them to determine if a scent trace on the ground that was made by a prey animal turned to the left or right side, so they can follow it with greater precision. Among the common lizards of Nepal, monitor lizards (family Varanidae) also have tongues with forked tips, but these large lizards have four very well developed legs, well visible external ears, and moveable eyelids. 2.

How many different species of snake are there? There are more than 3400 different species of snake on earth. Snakes can be found on all continents except Antarctica, and they have conquered the most divergent environments from the mountains of the Himalayas to the coral reefs of the Pacific Ocean. There are snakes that spend all of their life in the water, others that live underground in holes and burrows that they or other animals have dug, and yet others that spend their lives high up in the canopy of trees. Most snakes reproduce by laying eggs but some species give birth to fully developed young. Certain species of snake like pythons or the king cobra even guard and protect their eggs. Snakes exclusively eat other animals, and many species are capable of swallowing prey that is very big or bulky compared to their own body. By controlling the number of other animal species, and by serving as food to others like birds of prey and other predators (e.g., mongoose), snakes play an important role in the natural ecosystems and artificial agro-ecosystems. For farmers, snakes are very useful because they help to control rodent populations by eating the rats and mice that would otherwise damage crops or eat stored food. Which snakes are dangerous for humans? Most species of snake are harmless for humans. Many have no venom at all, and they either kill their prey by constriction or by pressing it to the ground, or simply swallow it alive. Many others produce secretions in specialized oral glands that help them to immobilize, kill and/or digest their prey and to act against harmful bacteria. From a biological point of view, these oral gland secretions are usually called venoms (and the glands in which they are produced, venom glands) if the snakes use them to quickly immobilize or kill their natural prey. This is usually achieved if the snakes do not only have toxic oral gland secretions, but also an effective venom apparatus to deliver these into their prey or enemy. The teeth of snakes play a key role in this. The most primitive type of dentition of snakes consists of teeth that are of similar size and shape anywhere in the mouth. Many snake species have a more differentiated dentition in which certain teeth are longer and have blade-like ridges or grooves. These can facilitate the penetration of the teeth into the prey and/or the application of toxic oral gland secretions. A large number of snake species has such enlarged teeth in the back of the upper 3.

Venomous Snakes of Nepal. jaw. Under usual circumstances, these so-called "rear-fanged snakes" cannot effectively apply their toxic oral gland secretions to human bite victims. The most sophisticated and effective venom apparatus, the so-called front-fanged venom apparatus, is composed of the following parts: Two much enlarged teeth for venom injection (also known as fangs) in the front of the upper jaw of the mouth. A venom duct that connects each fang with one well-developed venom gland located behind the eye on each side of the head..

A photographic guide. How can dangerously venomous snakes be distinguished from others? Recognizing which snake is dangerously venomous and which one is not is often difficult for non-experts. However, there are certain external features that can be very useful for distinguishing dangerous species from harmless ones even if they look superficially similar. In this section we will discuss and illustrate some of the most relevant ones in the context of Nepal. Green snakes In Nepal there are several species of snake with variable shades of light or dark green colouration, but only some of these are dangerous. Some important characteristics can be used to distinguish these: 1. In Nepal, green snakes with large scales on top of the head and a pupil of the eye that is round in daylight are harmless. For example, the non-venomous snake Orthriophis hodgsonii (Fig. 4) is often confused with venomous pit vipers in the hills of Nepal..

Fig. 6. The mildly venomous Green Cat-eyed Snake ( Boiga cyanea ) is similar to the dangerously venomous green pit vipers in having a pupil that is vertical in light, but differs from them in having very large scales on top of the head and lacking venom fangs in the front of the mouth. 6.

Fig. 8. Kramer's Green Pit Viper ( Trimeresurus septentrionalis ) from Nepal showing the location of the opening of the pit organ between the eye and the nostril (arrow), numerous small scales on top of the head, and the yellow eye with a pupil that is vertical in light. These features are characteristic for all "green pit vipers" in Nepal although the colour of the eye and the head can vary according to the species or sex of the snake. 7.

Fig. 9. Head of an adult White-lipped Pit Viper ( Trimeresurus cf. albolabris ) from southern Nepal, viewed from above. Note the numerous small scales covering the head. 8.

A photographic guide. Snakes with blotched colour pattern In Nepal, two species of python may be confused with some venomous snakes: The Burmese Python ( Python bivittatus ; see Fig. 10) and the Indian Rock Python ( Python molurus , see Fig. 11). Adult pythons are much longer (3 to over 7 m) than any of the vipers in Nepal, but smaller ones may look quite similar at first sight. Like pit vipers, pythons have visible heat-sensitive pit organs, but in the case of these pythons they are located on the snout tip and the first two upper lip scales, actually below the nostril, not between the eye and the nostril as in pit vipers. Also, the.

10. Venomous Snakes of Nepal. Fig. 12. Juvenile Russell's Viper ( Daboia russelii ) from Maharashtra, India..

11. A photographic guide. Fig. 14. Common Sand Boa ( Gongylophis conicus )..

Fig. 16. John's Sand Boa ( Eryx johnii ). 12. Venomous Snakes of Nepal.

13. A photographic guide. Other snakes that look like vipers In Nepal there are several species of snake that have a very similar appearance to the highly venomous pit vipers and Russell's Viper. Some of them have enlarged teeth in the front or back of their mouth and some are mildly venomous, but no cases of human envenoming have been reported. In contrast, pit vipers and Russell's Viper have very long venom fangs in the front of their mouth which can be erected for biting and folded back when the mouth is closed. None of these non-venomous viper lookalikes has a pit organ between eye and nostril. This distinguishes them from all the pit vipers. The pit organ of the latter (see Fig. 8 and 19) is used for thermoreception, especially to detect warm-blooded prey or enemies in the environment, even in total darkness. A very species-rich group of vipers, known to zoologists as the subfamily Crotalinae, is called pit vipers because of this organ. All known vipers in Nepal except Russell's Viper are pit vipers. Most of the pit vipers give birth to fully developed young, but some like Ovophis monticola (see Fig. 92) lay eggs which the mother will guard..

Venomous Snakes of Nepal. The Himalayan Pit Viper ( Gloydius himalayanus , see Fig. 20) is the only viper in Nepal that has few very large scales on top of the head like some of the non-venomous or mildly venomous lookalikes of.

Although some of them can produce very impressive hissing and growling sounds, their defensive display is actually very different from that of cobras. For example, cobras will spread the skin of their neck horizontally, displaying dark round 'V' or 'Y' or 'O' shaped marks on their neck, and will usually raise their forebody vertically off the ground, looking at their adversary (see Fig. 23). Rat snakes and racers, on the other hand, inflate their neck and forebody by inhaling air and extending their body in vertical direction (see Fig. 24). They also stay closer to the ground, bringing their forebody into S-shaped positions that will facilitate striking or darting off in an attempt to escape. Compared to cobras they also have more slender and much longer heads and much larger eyes. All of these snakes are very useful especially for farmers because they help to control populations of mice and rats. Some species of rat snake and racer kill their prey by constriction, others simply by pressing it onto the ground. Some have been found to produce certain toxins in their oral glands, but there has been no report of envenoming from any of the rat snake and racer species that occur in Nepal. However, 15.

Venomous Snakes of Nepal. Fig. 23. Spectacled Cobra ( Naja naja ) viewed from above, showing its typical defensive display that includes a raised forebody, neck skin spread to a "hood" with spectacle-shaped marks..

A photographic guide. Water snakes Water snakes that are common in and around rice/paddy fields and ponds are very often seen by people and sometimes confused with venomous snakes. The Striped Keelback ( Amphiesma stolatum ; see Fig. 27 and 28) is active by day and rarely bites. It is easily recognized by its pattern of blotches on the anterior body and distinct stripes on the posterior body and tail..

Wolf and Kukri snakes Looking similar to the highly dangerous kraits, the Common Wolf Snake ( Lycodon aulicus , see Fig. 31 and 32) belongs to those snakes that most commonly enter human houses or even live there permanently. These small snakes usually reach 40-80 cm and eat other small animals like skinks, geckos and mice. As they are also active at night, have a somewhat similar colour pattern and are usually quick to bite if they are touched or handled, they are often confused with kraits like the Common Krait ( Bungarus caeruleus ). However, the bites of Common Wolf Snakes are harmless, so this species contributes a great part of those snake bites that do not result in envenoming. In marked difference to kraits, the scales on the back of wolf snakes are all of similar size and shape. 18.

A photographic guide. Fig. 31 . Common Wolf Snake ( Lycodon aulicus ), adult female caught in a shop in the centre of Damak, Jhapa, Nepal..

Venomous Snakes of Nepal. Uniformly black and brown snakes In Nepal, there is a number of species of smaller snakes that have a uniformly black or brown colouration on the back side of their bodies (often with lighter bellies) and that are not cobras or rat snakes. Many of these are non-venomous or only mildly venomous and not dangerous to humans, but some are highly dangerous venomous snakes so it is important to recognize them. There are two different species of deadly venomous black krait found in Nepal, the Greater Black Krait ( Bungarus niger , see Fig. 34) and the Lesser Black Krait ( Bungarus lividus , see Fig. 35). Like all kraits, they differ from most snakes in Nepal in having one row of hexagonal scales along the middle of their back from neck to tail (on top of the vertebral column, therefore also called vertebral scales) that are much larger than the other scales on the back of their body..

A photographic guide. A. B. Fig. 35. (A and B) Head of a Lesser Black Krait ( Bungarus lividus ) in close-up view. Note the small eye, pointed snout and head that is not distinct from the neck. The pupil of the eye is white because the snake is a preserved museum specimen; in live snakes the eye appears like a small jet black bead. The black krait species Bungarus niger and Bungarus lividus differ in the size of these enlarged scales. In Bungarus niger , they are very large, like in all other species of krait. In Bungarus lividus , they are only slightly larger than the bordering scales on the back of the body..

22. Venomous Snakes of Nepal. Cat snakes are rear-fanged snakes that use enlarged teeth in the back of their mouth to apply venom to their prey. The cat snake species in Nepal are considered to be mildly venomous, and no cases of human envenoming by them have been reported. The Tawny Cat Snake ( Boiga ochracea ) is widely distributed in the lowlands and hills of Nepal and neighbouring countries. It is often reddish-brown, yellowish-brown or even coral red, but darker specimens may be confused with black kraits. Like kraits, it is active at night, but unlike kraits it mostly climbs in house walls, bushes or shrubs where it preys on lizards, birds and small mammals. Note the large eye with well visible vertical pupil..

A photographic guide. How many snake species occur in Nepal, and how many of these are dangerous? So, far 89 species of snake have been recorded from Nepal, but the exact number remains to be determined because large parts of the country are still unexplored from a biological point of view, and some published records of snake species that are difficult to identify require further study and verification. Among this great diversity of snakes, we know with certainty of 17 species of snake that occur in Nepal and have the front-fanged type of venom apparatus and thus are considered to be highly venomous and dangerous. These snakes can be subdivided further into two groups: Kraits, cobras, king cobras and coral snakes (family Elapidae) Snakes of this group have two relatively short fangs that are firmly attached and immobile, one on each side of the upper front of their mouth (on the maxillary bone). Although short, their teeth have deep grooves on the outside that efficiently serve as canals to transport venom into the prey or enemy. Some of these snakes, especially kraits,.

Venomous Snakes of Nepal. Bungarus bungaroides Himalayan Krait (English), Pahadi Karet, Himali Karet (Nepali) Identification: Usually 1-1.5 m long, hatchlings about 30 cm. Shiny black, brownish black or grey body and tail with very narrow white or yellowish rings. Light rings often much obscured in large adults, less than one scale wide on body but extending completely across belly where they are broader. Tail tip pointed. Fifteen rows of scales across back, scales along vertebral ridge much larger than bordering scales. Scales on lower side of tail divided..

A photographic guide. Fig. 40. Lower side of tail of the Himalayan Krait ( Bungarus bungaroides ) showing light rings and divided subcaudal scales..

26. Venomous Snakes of Nepal. Fig. 44. Large adult Himalayan Krait ( Bungarus bungaroides ; same snake as in Fig. 41); note light rings across the dark belly..

A photographic guide. Bungarus caeruleus Common Krait (English), Seto-kalo Chure Sarpa, Gadaich, Chure Sarpa (Nepali) Identification: Usually 0.8-1.2 m (up to 1.75 m) long, hatchlings about 25 cm. Very narrow white bands on back of shiny black to dark brown body and tail (often absent from anterior body). Belly uniformly light. Tail tip pointed. Fifteen rows of scales across back, scales along vertebral ridge much larger than bordering scales. Scales on lower side of tail undivided..

28. Venomous Snakes of Nepal. Fig. 46. Adult Common Krait ( Bungarus caeruleus ) from near Rangpur, north-western Bangladesh, showing reduction of light bands on anterior body..

A photographic guide. Bungarus fasciatus Banded Krait (English), Gangawari, Panhelo-kalo Chure Sarpa, Kanthamala, Laxmi Sanp, Raja Sanp, Maher, Gwala Sarpa, Ahiriniya Sanp (Nepali) Identification: Usually 1-2 m (up to 2.25 m) long, hatchlings about 30-35 cm. Broad black and light rings of similar width on body and tail. Light rings yellow in adults, cream to white in juveniles, extending completely across belly. Tail tip blunt, not pointed, sometimes mistaken for a second head. Body triangular, vertebral column forming distinct ridge along top of the back. Fifteen rows of scales across back, scales along vertebral ridge much larger than bordering scales. Scales on lower side of tail undivided..

Venomous Snakes of Nepal. Fig. 50. Juvenile Banded Kraits ( Bungarus fasciatus ) have a pattern of white to cream and black rings on the body. The white rings become yellow as the snakes grow..

A photographic guide. Fig. 52. Ventral side of a Banded Krait ( Bungarus fasciatus ). The light and black bands encircle the body completely, and they are of similar width..

32. Venomous Snakes of Nepal. Bungarus lividus Lesser Black Krait (English), Sano Kalo Karet (Nepali) Identification: Usually 60-90 cm long, rarely more than 1 m. Shiny black, brownish black or brown head, body and tail with no light bands or lines. Lower side of head and anterior body whitish, obscured by brown pigment on lower side of posterior body and tail. Tail tip pointed. Fifteen rows of scales across the back. Scales along vertebral ridge only slightly larger than the bordering scales or of normal size. Scales on lower side of tail undivided..

33. A photographic guide. Venom effects: The venom of B. lividus has not been studied yet. Envenoming by this species in Nepal has caused burning sensation at the bite site and over the whole body, abdominal pain, vomiting, slurred speech, ptosis, and progressive generalized neuromuscular paralysis leading to respiratory distress and death. Neurotoxic and possibly myotoxic envenoming and their complications should be anticipated when treating a patient bitten by this snake..

Venomous Snakes of Nepal. Bungarus niger Greater Black Krait (English), Thulo Kalo Karet (Nepali) Identification: Usually 70-90 cm long, rarely up to 1.3 m. Shiny black, brownish black or dark chocolate brown head, body and tail with no light bands or lines. Lower side of head and anterior body dirty white to yellow, obscured by brown pigment on lower side of posterior body and tail. Tail tip pointed. Fifteen rows of scales across the back, scales along vertebral ridge much larger than the bordering scales. Scales on lower side of tail undivided..

A photographic guide. Fig. 59. Greater Black Krait ( Bungarus niger ) from Naudanda, Kaski, Gandaki, Nepal, 1450 m altitude. Detailed view of the head of the same snake. Note the very small eye that appears jet black without visible pupil. 35.

Venomous Snakes of Nepal. Bungarus walli Wall's Krait (English), Bairi Karet, Gadaich (Nepali) Identification: Usually 1-1.3 m long (up to 1.65 m), hatchlings about 25-30 cm. Shiny black, brownish black or grey head, body and tail with numerous very narrow white or yellowish bands. Light bands often much obscured on anterior body and less than one scale wide. Belly uniformly white. Tail tip pointed. Seventeen (rarely 19 or 21) rows of scales across the back; scales along vertebral ridge much larger than the bordering scales. Scales on lower side of tail undivided..

37. A photographic guide. Fig. 62. Wall’s Krait ( Bungarus walli , A) and Common Krait ( Bungarus caeruleus , B). Although the two species look similar, they can be reliably distinguished by the number of scale rows across their back: Bungarus caeruleus has only 15, but Bungarus walli 17 (rarely 19-21)..

Medical importance and behaviour: One of the most common and most dangerous causes of snake bite envenoming in Nepal. Active by day and night, especially at dawn and dusk. Feeds mainly on rodents, frogs, birds; swims well. Raises forebody, displays extended neck skin "hood" and hisses when disturbed. Venom effects: Envenoming by N. naja causes local swelling of the bitten part and in a large number of cases also progressive paralysis of the peripheral nervous system, leading to respiratory paralysis and death due to asphyxia. Neurotoxic features of N. naja envenoming are typically reversible by antivenom and anticholinesterase treatment. Local envenoming may result in tissue necrosis and contractures requiring surgical intervention. 38.

39. A photographic guide. Fig. 64. Spectacled Cobra ( Naja naja ) showing its defensive display with "spectacle-shaped" marks on the back of its neck skin while trying to escape..

Venomous Snakes of Nepal. Naja kaouthia Monocellate Cobra, Monocled Cobra (English), Goman, Paniyadarad (Nepali) Identification: Usually 1.5-1.6 m (up to 2.3 m) long, hatchlings about 25-35 cm. Light brown, tan to black ground colour with monocellate (O-shaped) mark on neck, two black spots on lower side of throat and 2 or 3 broad black cross- bars on the belly behind the hood. Twenty-one (sometimes 19-23) rows of scales across the back at midbody; scales along vertebral ridge of same size as bordering scales. Tail tip pointed; scales on lower side of tail divided..

41. A photographic guide. Fig. 67. Monocellate Cobra ( Naja kaouthia ) in a snake charmer’s collection in Bangladesh..

Venomous Snakes of Nepal. Ophiophagus hannah King Cobra (English), Raj Goman, Kalinag, Kenwata (Nepali) Identification: Usually 3-3.5 m (up to 5.5 m) long, hatchlings about 40-60 cm. It is the largest venomous snake in the world. Shiny black to brown, grey or tan ground colour. Juveniles with distinct narrow white or yellowish bands on body and tail, faded and indistinct in most adults. Back of the neck without spectacle-shaped or monocle-shaped spots. A pair of large occipital shields in contact with one another on top of the head. Tail tip pointed. Fifteen rows of scales across back at midbody, scales along vertebral ridge not larger than bordering scales. Scales on lower side of tail undivided anteriorly and divided posteriorly. Distribution and habitat: Likely throughout the lowlands and lower mountains of Nepal up to 3500 m altitude. Also India, Bangladesh, Bhutan and Southeast Asia. Prefers forests and plantations in the vicinity of water and bamboo stands; rarely seen in disturbed agricultural lands. Medical importance and behaviour: King cobras are active by day, move rapidly, climb and swim well. They mainly feed on snakes including pythons, sometime also on other reptiles like monitor lizards. When cornered they raise their anterior body and emit a deep growling sound. Bites appear to be rare in Nepal..

43. A photographic guide. Fig. 70. King Cobra ( Ophiophagus hannah ) from Orissa, India..

Venomous Snakes of Nepal. Sinomicrurus macclellandi univirgatus MacClelland´s Coral Snake (English), Mugasanp, Karkat Nag (Nepali) Identification: Usually 50-80 cm long. Head black above with a wide white, yellow or cream coloured transverse stripe behind the eyes. Back of the body reddish brown with or without a black vertebral stripe or remains of incomplete thin black transverse bands on the flanks; below yellowish with black bars or quadrangular spots. Thirteen rows of scales across the back; scales along vertebral ridge not larger than bordering scales. Tail short with pointed tip. Scales on lower side of tail divided (rarely some undivided)..

A photographic guide. Fig. 72. MacClelland's Coral Snake ( Sinomicrurus macclellandi ) from Arunachal Pradesh, India. Note the broad white cross-band behind the eyes..

46. Venomous Snakes of Nepal. Fig. 75. MacClelland's Coral Snake ( Sinomicrurus macclellandi univirgatus ) from the Kathmandu Valley, Nepal. In this subspecies the black pattern on the back is reduced to a stripe or series of spots along the back..

47. A photographic guide. Fig. 76. Kramer's Pit Viper ( Trimeresurus septentrionalis ), adult female from Pyaudi, Kaski, Gandaki, Nepal, 1050 m above sea level..