Russell's viper

Last updated

Russell's viper
Daboia russelii A Chawla01.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Genus: Daboia
Species:
D. russelii
Binomial name
Daboia russelii
(Shaw & Nodder, 1797)
South East Asia location-Daboia-russelii.svg
Daboia russelii distribution
Synonyms
  • Coluber russeliiShaw & Nodder, 1797
  • Coluber daboie
    Latreille In Sonnini & Latreille, 1801
  • Coluber trinoculus
    Schneider In Bechstein, 1802
  • Vipera daboya Daudin, 1803
  • Vipera elegansDaudin, 1803
  • Coluber triseriatus Hermann, 1804
  • Vipera russelii Gray, 1831
  • Daboia elegans Gray, 1842
  • Daboia russelii Gray, 1842
  • Daboia pulchellaGray, 1842
  • Echidna russellii Steindachner, 1869
Russell's viper (Daboia russelli) in a sensing moment Daboia Russelli in a Sensing moment.jpg
Russell's viper (Daboia russelli) in a sensing moment

Russell's viper (Daboia russelii) is a highly venomous snake in the family Viperidae native to the Indian subcontinent and one of the big four snakes in India. It was described in 1797 by George Shaw and Frederick Polydore Nodder, and named after Patrick Russell, who wrote about it in his 1796 work An account of Indian serpents, collected on the coast of Coromandel.

Contents

Taxonomy

English naturalist George Shaw—with illustrator Frederick Polydore Nodder—in The Naturalist's Miscellany: Or, Coloured Figures Of Natural Objects; Drawn and Described Immediately From Nature formally described the species in 1797 as Coluber russelii, from a specimen presented to the British Museum by Scottish herpetologist Patrick Russell. [1] Russell had written of the species in his 1796 work An account of Indian serpents, collected on the coast of Coromandel, confirming its highly venomous nature by experimenting on chickens and dogs. He added the native people called it katuka retula poda. [2]

Analysis of morphological and mitochondrial DNA data shows that the eastern subspecies of D. russelii should be considered a separate species, Daboia siamensis. [3]

A number of other subspecies may be encountered in literature, [4] including:

The correct spelling of the species, D. russelii, has been, and still is, a matter of debate. Shaw and Nodder (1797), in their account of the species Coluber russelii, named it after Patrick Russell, but apparently misspelled his name, using only one "L" instead of two. Russell (1727–1805) was the author of An Account of Indian Serpents (1796) and A Continuation of an Account of Indian Serpents (1801). McDiarmid et al. (1999) are among those who favor the original misspelling, citing Article 32c (ii) of the International Code of Zoological Nomenclature. Others, such as Zhao and Adler (1993) favor russellii. [5]

Etymology

The species is named after Patrick Russell (1726–1805), [6] a Scottish herpetologist who first described many of India's snakes, and the name of the genus is from the Hindi word[ specify ] meaning "that lies hid", or "the lurker". [7]

In English, common names of D. russelii include Russell's viper, [4] [8] [9] [10] chain viper, [8] [10] Indian Russell's viper, [11] [12] common Russell's viper, [13] seven pacer, [14] chain snake, and scissors snake. [15]

Description

Head of the Russell's viper File-Daboia russelii head A Chawla02.jpg
Head of the Russell's viper
Large fangs Russell's Viper Fangs (3972411624).jpg
Large fangs
Russell's viper in Pune Zoo Russells viper in pune zoo.jpg
Russell's viper in Pune Zoo

The head is flattened, triangular, and distinct from the neck. The snout is blunt, rounded, and raised. The nostrils are large, each in the middle of a large, single nasal scale. The lower edge of the nasal scale touches the nasorostral scale. The supranasal scale has a strong crescent shape and separates the nasal from the nasorostral scale anteriorly. The rostral scale is as broad as it is high. [4]

The crown of the head is covered with irregular, strongly fragmented scales. The supraocular scales are narrow, single, and separated by six to nine scales across the head. The eyes are large, flecked with yellow or gold, and surrounded by 10–15 circumorbital scales. The snake has 10–12 supralabials, the fourth and fifth of which are significantly larger. The eye is separated from the supralabials by three or four rows of suboculars. Of the two pairs of chin shields, the front pair is notably enlarged. The two maxillary bones support at least two, and at the most five or six, pairs of fangs at a time: the first are active and the rest replacements. [4] The fangs attain a length of 16.5 mm (0.65 in) in the average specimen. [16]

The body is stout, the cross-section of which is rounded to circular. The dorsal scales are strongly keeled; only the lowest row is smooth. Mid-body, the dorsal scales number 27–33. The ventral scales number 153–180. The anal plate is not divided. The tail is short—about 14% of the total length—with the paired subcaudals numbering 41–68. [4]

Dorsally, the color pattern consists of a deep yellow, tan, or brown ground color, with three series of dark brown spots that run the length of the body. Each of these spots has a black ring around it, the outer border of which is intensified with a rim of white or yellow. The dorsal spots, which usually number 23–30, may grow together, while the side spots may break apart. The head has a pair of distinct dark patches, one on each temple, together with a pinkish, salmon, or brownish V or X marking that forms an apex towards the snout. Behind the eye is a dark streak, outlined in white, pink, or buff. The venter is white, whitish, yellowish, or pinkish, often with an irregular scattering of dark spots. [4]

Russell's viper grows to a maximum body and tail length of 166 cm (65 in) and averages about 120 cm (47 in) in mainland Asia. On islands, it is slightly shorter on average. [4] It is more slender than most vipers. [17] The following dimensions for a "fair-sized adult specimen" were reported in 1937: [18]

Distribution and habitat

Daboia full.jpg
Russellsviper sal.jpg
Russell's viper from India

Russell's viper is found in India, Sri Lanka, Bangladesh, Nepal, and Pakistan. Populations from South-East Asia previously assigned to this species are now considered to be part of a different species, Daboia siamensis . [3] The type locality is listed as "India". More specifically, this would be the Coromandel Coast, by inference of Russell (1796). [5]

Within its range, it can be common in some areas, but scarce in others. [17] In India, it is abundant in Punjab, very common along the West Coast and its hills, and in southern India, especially in the state of Karnataka and north to Bengal. It is uncommon to rare in the Ganges valley, northern Bengal, and Assam.

Russell's viper is not restricted to any particular habitat, but does tend to avoid dense forests. The snake is mostly found in open, grassy or bushy areas, but may also be found in second growth forests (scrub jungles), on forested plantations and farmland. It is most common in plains, coastal lowlands, and hills of suitable habitat. Generally, it is not found at altitude, but has been reported as far up as 2300–3000 m (7,500–9,800 ft). Humid environments, such as marshes, swamps, and rain forests, are avoided. [4]

This species is often found in highly urbanized areas and settlements in the countryside, the attraction being the rodents commensal with man. [16] As a result, those working outside in these areas are most at risk of being bitten. D. russelii does not associate as closely with human habitation as Naja and Bungarus species (cobras and kraits). [4]

Behaviour and ecology

Russell's viper is terrestrial and active primarily as a nocturnal forager. However, during cool weather, it alters its behavior and becomes more active during the day. [4] Adults are reported to be slow and sluggish unless pushed beyond a certain limit, after which they can become very aggressive. Juveniles, though, are generally more nervous. [4] When threatened, they form a series of S-loops, raise the first third of the body, and produce a hiss that is supposedly louder than that of any other snake. When striking from this position, they can exert so much force that even a large individual can lift most of its body off the ground in the process. [4] These snakes are strong and may react violently to being picked up. [19] The bite may be a snap, or they may hang on for many seconds. [16]

Although this genus does not have the heat-sensitive pit organs common to the Crotalinae, it is one of a number of viperines that are apparently able to react to thermal cues, further supporting the notion that they, too, possess a heat-sensitive organ. [20] [21] The identity of this sensor is not certain, but the nerve endings in the supranasal sac of these snakes resemble those found in other heat-sensitive organs. [22]

Reproduction

Russell's viper is ovoviviparous. [17] Mating generally occurs early in the year, although pregnant females may be found at any time. The gestation period is more than six months. Young are produced from May to November, but mostly in June and July. It is a prolific breeder. Litters of 20–40 are common, [4] although fewer offspring may occur, as few as one. [16] The reported maximum is 75 [23] in a single litter. At birth, juveniles are 215–260 mm (8.5–10.2 in) in total length. The minimum total length for a gravid female is about 100 cm (39 in). It seems that sexual maturity is achieved in 2–3 years. In one case, it took a specimen nearly 4.5 hours to give birth to 11 young. [4]

Prey

Russell's viper hunting Daboia head sal.jpg
Russell's viper hunting

Russell's viper feeds primarily on rodents, although it will also eat small reptiles, land crabs, scorpions, and other arthropods. Juveniles are crepuscular, feeding on lizards and foraging actively. As they grow and become adults, they begin to specialize in rodents. Indeed, the presence of rodents and lizards is the main reason they are attracted to human habitation. [4] Juveniles are known to be cannibalistic. [16]

Mimicry

The rough-scaled sand boa Eryx conicus possibly mimics the appearance of Russell's viper Russellsboa2 sal.jpg
The rough-scaled sand boa Eryx conicus possibly mimics the appearance of Russell's viper

Some herpetologists believe, because D. russelii is so successful as a species and has such a fearful reputation within its natural environment, another snake has come to mimic its appearance. Superficially, the rough-scaled sand boa Eryx conicus has a color pattern that often looks like that of D. russelii, though it is completely harmless. [4] [18]

Venom

Venom of this species is delivered by means of solenoglyphous dentition. [24] The quantity of venom produced by individual specimens of D. russelii is considerable. Venom yields for adult specimens have been reported as 130–250 mg, 150–250 mg, and 21–268 mg. For 13 juveniles with an average total length of 79 cm (31 in), the venom yield ranged from 8 to 79 mg (mean 45 mg). [4]

The LD50 in mice, which is used as a possible indicator of snake venom toxicity, is: 0.133 mg/kg intravenous, [25] 0.40 mg/kg intraperitoneal, [26] about 0.75 mg/kg subcutaneous. [27] For most humans, a lethal dose is about 40–70 mg, well within the amount that can be delivered in one bite. In general, the toxicity depends on a combination of five different venom fractions, each of which is less toxic when tested separately. Venom toxicity and bite symptoms in humans vary within different populations and over time. [4] In another study, Meier and Theakston reported that the lethality of venom of Russell viper varies with change in route of injection, as their results predicts the LD50 of 0.4 mg/kg through intraperitoneal (I.P) route, 0.75 mg/kg/subcutaneous (S.C) route and 0.3 mg/kg through intravenous (I.V) route. [28]

Symptoms

Envenomation symptoms begin with pain at the site of the bite, immediately followed by swelling of the affected extremity. Bleeding is a common symptom, especially from the gums and in the urine, and sputum may show signs of blood within 20 minutes after the bite. The blood pressure drops, and the heart rate falls. Blistering occurs at the site of the bite, developing along the affected limb in severe cases. Necrosis is usually superficial and limited to the muscles near the bite, but may be severe in extreme cases. Vomiting and facial swelling occur in about one-third of all cases. [4] Kidney failure (renal failure) also occurs in approximately 25–30 percent of untreated bites. Severe disseminated intravascular coagulation also can occur in severe envenomations. Early medical treatment and early access to antivenom can prevent and drastically reduce the chance of developing the severe/potentially lethal complications.

Severe pain may last for 2–4 weeks. It may persist locally, depending on the level of tissue damage. Often, local swelling peaks within 48–72 hours, involving both the affected limb and the trunk. If swelling up to the trunk occurs within 1–2 hours, envenomation is likely to be massive. Discoloration may occur throughout the swollen area as red blood cells and plasma leak into muscle tissue. [15] Death from septicaemia or kidney, respiratory, or cardiac failure may ensue 1 to 14 days after the bite, or sometimes later. [16]

A study in The Lancet showed that out of a sample of people who survived bites by D. russelii, 29% suffered severe damage to their pituitary glands, which later caused hypopituitarism. [29] Other scientific studies support the hypothesis that D. russelii bites can cause hypopituitarism. [30] [31]

Antivenom treatment

In India, the Haffkine Institute prepares a polyvalent antivenom that is used to treat bites from this species. [16] In late 2016, a new antivenom had been developed by the Costa Rican Clodomiro Picado Institute, and clinical trials were started in Sri Lanka. [32]

Clinical use

Because this venom is so effective at inducing thrombosis, it has been incorporated into an in vitro diagnostic test for blood clotting that is widely used in hospital laboratories. This test is often referred to as dilute Russell's viper venom time (dRVVT). The coagulant in the venom directly activates factor X, which turns prothrombin into thrombin in the presence of factor V and phospholipid. The venom is diluted to give a clotting time of 23 to 27 seconds and the phospholipid is reduced to make the test extremely sensitive to phospholipid. The dRVVT test is more sensitive than the aPTT test for the detection of lupus anticoagulant (an autoimmune disorder), because it is not influenced by deficiencies in clotting factors VIII, IX or XI. [33]

Related Research Articles

<span class="mw-page-title-main">King cobra</span> Venomous snake species from Asia

The king cobra is a venomous snake endemic to Asia. The sole member of the genus Ophiophagus, it is not taxonomically a true cobra, despite its common name and some resemblance. With an average length of 3.18 to 4 m and a record length of 5.85 m (19.2 ft), it is the world's longest venomous snake. The species has diversified colouration across habitats, from black with white stripes to unbroken brownish grey. The king cobra is widely distributed albeit not commonly seen, with a range spanning from the Indian Subcontinent through Southeastern Asia to Southern China. It preys chiefly on other snakes, including those of its own kind. This is the only ophidian that constructs an above-ground nest for its eggs, which are purposefully and meticulously gathered and protected by the female throughout the incubation period.

<span class="mw-page-title-main">Snakebite</span> Injury caused by bite from snakes

A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. Vomiting, blurred vision, tingling of the limbs, and sweating may result. Most bites are on the hands, arms, or legs. Fear following a bite is common with symptoms of a racing heart and feeling faint. The venom may cause bleeding, kidney failure, a severe allergic reaction, tissue death around the bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death.

<span class="mw-page-title-main">Snake venom</span> Highly modified saliva containing zootoxins

Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is injected by unique fangs during a bite, whereas some species are also able to spit venom.

<span class="mw-page-title-main">Banded krait</span> Species of Asian elapid snake

The banded krait is a species of elapids endemic to Asia, from Indian Subcontinent through Southeast Asia to Southern China. With a maximum length exceeding 2 m, it is the longest krait with a distinguishable gold and black pattern. While this species is generally considered timid and docile, resembling other members of the genus, its venom is highly neurotoxic which is potentially lethal to humans. Although toxicity of the banded krait based upon murine LD50 experiments is lower than that of many other kraits, its venom yield is the highest due to its size.

<i>Bitis nasicornis</i> Species of snake

Bitis nasicornis is a viper species belonging to the genus Bitis, part of a subfamily known as "puff-adders", found in the forests of West and Central Africa. This large viper is known for its striking coloration and prominent nasal "horns". No subspecies are currently recognized. Its common names include butterfly viper, rhinoceros viper, river jack and many more. Like all other vipers, it is venomous.

<span class="mw-page-title-main">Big Four (Indian snakes)</span> Group of venomous Indian snakes

The four venomous snake species responsible for causing the greatest number of medically significant human snake bite cases on the Indian subcontinent are sometimes collectively referred to as the Big Four. They are as follows:

  1. Russell's viper, Daboia russelii
  2. Common krait, Bungarus caeruleus
  3. Indian cobra, Naja naja
  4. Indian saw-scaled viper, Echis carinatus
<span class="mw-page-title-main">Caspian cobra</span> Species of snake

The Caspian cobra, also called the Central Asian cobra, ladle snake, Oxus cobra, or Russian cobra, is a species of highly venomous snake in the family Elapidae. The species is endemic to Central Asia. Described by Karl Eichwald in 1831, it was for many years considered a subspecies of the Indian cobra until genetic analysis revealed it to be a distinct species.

<i>Hydrophis schistosus</i> Species of snake

Hydrophis schistosus, commonly known as the beaked sea snake, hook-nosed sea snake, common sea snake, or the Valakadeyan sea snake, is a highly venomous species of sea snake common throughout the tropical Indo-Pacific. This species is implicated in more than 50% of all bites caused by sea snakes, as well as the majority of envenomings and fatalities.

<span class="mw-page-title-main">Venomous snake</span> Species of the suborder Serpentes that produce venom

Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or grooved fangs, although some venomous snakes lack well-developed fangs. Common venomous snakes include the families Elapidae, Viperidae, Atractaspididae, and some of the Colubridae. The toxicity of venom is mainly indicated by murine LD50, while multiple factors are considered to judge the potential danger to humans. Other important factors for risk assessment include the likelihood that a snake will bite, the quantity of venom delivered with the bite, the efficiency of the delivery mechanism, and the location of a bite on the body of the victim. Snake venom may have both neurotoxic and hemotoxic properties. There are about 600 venomous snake species in the world.

<i>Echis</i> Genus of snakes

Echis is a genus of vipers found in the dry regions of Africa, the Middle East, India, Sri Lanka and Pakistan. They have a characteristic threat display, rubbing sections of their body together to produce a "sizzling" warning sound. The name Echis is the Latin transliteration of the Greek word for "viper" (ἔχις). Like all vipers, they are venomous. Their common name is "saw-scaled vipers" and they include some of the species responsible for causing the most snakebite cases and deaths in the world. Twelve species are currently recognized.

<i>Vipera</i> Genus of snakes

Vipera is a genus of vipers. It has a very wide range, being found from North Africa to just within the Arctic Circle and from Great Britain to Pacific Asia. The Latin name vīpera is possibly derived from the Latin words vivus and pario, meaning "alive" and "bear" or "bring forth"; likely a reference to the fact that most vipers bear live young. Currently, 21 species are recognized. Like all other vipers, the members of this genus are venomous.

<i>Vipera ammodytes</i> Species of snake

Vipera ammodytes, commonly known as horned viper, long-nosed viper, nose-horned viper, and sand viper, poskok is a species of viper found in southern Europe, mainly northern Italy, the Balkans, and parts of Asia Minor. Like all other vipers, it is venomous. It is reputed to be the most dangerous of the European vipers due to its large size, long fangs and high venom toxicity. The specific name, ammodytes, is derived from the Greek words ammos, meaning "sand", and dutes, meaning "burrower" or "diver", despite its preference for rocky habitats. Five subspecies are currently recognized, including the nominate subspecies described here.

<i>Naja</i> Genus of snakes

Naja is a genus of venomous elapid snakes commonly known as cobras. Members of the genus Naja are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Africa, Southwest Asia, South Asia, and Southeast Asia. Several other elapid species are also called "cobras", such as the king cobra and the rinkhals, but neither is a true cobra, in that they do not belong to the genus Naja, but instead each belong to monotypic genera Hemachatus and Ophiophagus.

<i>Vipera aspis</i> Species of snake

Vipera aspis is a viper species found in southwestern Europe. Its common names include asp, asp viper, European asp, and aspic viper, among others. Like all other vipers, it is venomous. Bites from this species can be more severe than from the European adder, V. berus; not only can they be very painful, but approximately 4% of all untreated bites are fatal. The specific epithet, aspis, is a Greek word that means "viper." Five subspecies are currently recognized, including the nominate subspecies described here.

<i>Daboia siamensis</i> Species of snake

Daboia siamensis is a venomous viper species, which is endemic to parts of Southeast Asia, southern China and Taiwan. It was formerly considered to be a subspecies of Daboia russelii, but was elevated to species status in 2007.

<span class="mw-page-title-main">Horned adder</span> Species of snake

The horned adder is a viper species. It is found in the arid region of southwest Africa, in Angola, Botswana, Namibia; South Africa, and Zimbabwe. It is easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized. Like all other vipers, it is venomous.

<i>Montivipera xanthina</i> Species of snake

Montivipera xanthina, known as the rock viper, coastal viper, Ottoman viper, and by other common names, is a viper species found in northeastern Greece and Turkey, as well as certain islands in the Aegean Sea. Like all other vipers, it is venomous. No subspecies are currently recognized.

<span class="mw-page-title-main">Epidemiology of snakebites</span>

Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. 325 species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities.

<i>Daboia</i> Genus of snakes

Daboia is a genus of venomous vipers.

References

  1. Shaw, George (1797). "The Russelian Snake". The Naturalist's Miscellany. 8: 291–293.
  2. Russell, Patrick (1796). An account of Indian serpents, collected on the coast of Coromandel. Vol. 1. London: W. Bulmer and Co. Shakespeare-Press. p. 10. Archived from the original on 2023-02-10. Retrieved 2020-08-15.
  3. 1 2 Thorpe RS, Pook CE, Malhotra A (2007). "Phylogeography of the Russell's viper (Daboia russelii) complex in relation to variation in the colour pattern and symptoms of envenoming". Herpetological Journal. 17: 209–18.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Mallow D, Ludwig D, Nilson G (2003). True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. 359 pp. ISBN   0-89464-877-2.
  5. 1 2 McDiarmid RW, Campbell JA, Touré TA (1999). Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1. Washington, District of Columbia: Herpetologists' League. 511 pp. ISBN   1-893777-00-6 (series). ISBN   1-893777-01-4 (volume).
  6. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN   978-1-4214-0135-5. (Daboia russelii, pp. 229-230).
  7. Weiner ESC, Simpson JA (editors) (1991). The Compact Oxford English Dictionary: New Edition. USA: Oxford University Press. ISBN   0-19-861258-3.
  8. 1 2 Snakes of Thailand: Venomous snakes Archived 2016-03-30 at the Wayback Machine at Siam-Info Archived 2016-05-06 at the Wayback Machine . Retrieved 20 October 2006.
  9. Daboia russelii at the Reptarium.cz Reptile Database . Accessed 2 August 2007.
  10. 1 2 . Retrieved 20 October 2006.
  11. Captive Care of the Russell's viper Archived 2008-04-09 at the Wayback Machine at VenomousReptiles.org. Retrieved 14 March 2007. Archived April 9, 2008, at the Wayback Machine
  12. Somaweera A (2007). Checklist of the Snakes of Sri Lanka. Peradeniya, Sri Lanka: Department of Zoology, Faculty of Science, University of Peradeniya. PDF Archived 2008-09-20 at the Wayback Machine at Sri Lanka Reptile Archived 2009-08-18 at the Wayback Machine . Retrieved 14 March 2007.
  13. Mehrtens JM (1987). Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN   0-8069-6460-X.
  14. Brown JH (1973). Toxicology and Pharmacology of Venoms from Poisonous Snakes. Springfield, Illinois: Charles C. Thomas. 184 pp. LCCCN 73-229. ISBN   0-398-02808-7.
  15. 1 2 United States Navy (1991). Poisonous Snakes of the World. New York: United States Government/Dover Publications Inc. 203 pp. ISBN   0-486-26629-X.
  16. 1 2 3 4 5 6 7 Daniel, J.C. (2002). "Russell's viper". The Book of Indian Reptiles and Amphibians. Oxford, USA: Oxford University Press. pp. 148–151. ISBN   0-19-566099-4.
  17. 1 2 3 Stidworthy, J. (1974). Snakes of the World (Revised ed.). New York: Grosset & Dunlap Inc. ISBN   0-448-11856-4.
  18. 1 2 Ditmars, R.L. (1937). Reptiles of the World: The Crocodilians, Lizards, Snakes, Turtles and Tortoises of the Eastern and Western Hemispheres. New York: The MacMillan Company.
  19. Whitaker Z (1989). Snakeman: The Story of a Naturalist. Bombay: India Magazine Books. 184 pp. ASIN B0007BR65Y.
  20. Krochmal AR, Bakken GS (August 2003). "Thermoregulation is the pits: use of thermal radiation for retreat site selection by rattlesnakes". J. Exp. Biol. 206 (Pt 15): 2539–45. doi: 10.1242/jeb.00471 . PMID   12819261. Archived from the original on 2023-02-10. Retrieved 2009-11-29.
  21. Krochmal AR, Bakken GS, LaDuc TJ (2004). "Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)". J. Exp. Biol. 207 (Pt 24): 4231–8. doi: 10.1242/jeb.01278 . PMID   15531644. Archived from the original on 2023-02-10. Retrieved 2008-02-22.
  22. York DS, Silver TM, Smith AA (1998). "Innervation of the supranasal sac of the puff adder". Anat. Rec. 251 (2): 221–5. doi: 10.1002/(SICI)1097-0185(199806)251:2<221::AID-AR10>3.0.CO;2-Q . PMID   9624452.
  23. "Russell's Viper delivers 75 snakelets". Bangalore Mirror. Archived from the original on 2020-07-11. Retrieved 2020-07-11.
  24. Mao, Shou-Hsian (May 19, 1967). "Bite Patterns of Taiwan Venomous and Non-Venomous Snakes" (PDF). zoolstud.sinica.edu.tw. Archived (PDF) from the original on December 23, 2021. Retrieved December 23, 2021.
  25. "LD50 - intravenous". Archived from the original on 2011-07-16. Retrieved 2012-01-08.
  26. "LD50 - intraperitoneal". Archived from the original on 2009-07-18. Retrieved 2012-01-08.
  27. "LD50 - subcutaneous". Archived from the original on 2005-02-05. Retrieved 2012-01-08.
  28. Meier, J; Theakston, RD (1986). "Approximate LD50 determinations of snake venoms using eight to ten experimental animals". Toxicon. 24 (4): 395–401. doi:10.1016/0041-0101(86)90199-6. PMID   3715904.
  29. "The deadly Russell Viper: How the snake's venom affects humans". May 4, 2015. Archived from the original on December 13, 2020. Retrieved November 29, 2020.
  30. Tun-Pe; Warrell, D. A.; Tin-Nu-Swe; Phillips, R. E.; Moore, R. A.; Myint-Lwin; Burke, C. W. (3 October 1987). "Acute and chronic pituitary failure resembling Sheehan's syndrome following bites by Russell's viper in Burma". The Lancet. 330 (8562): 763–767. doi:10.1016/s0140-6736(87)92500-1. PMID   2888987. S2CID   41839362.
  31. Antonypillai, C. N.; Wass, J. A. H.; Warrell, D. A.; Rajaratnam, H. N. (2010). "Hypopituitarism following envenoming by Russell's Vipers (Daboia siamensis and D. russelii ) resembling Sheehan's syndrome: First case report from Sri Lanka, a review of the literature and recommendations for endocrine management". QJM. 104 (2): 97–108. doi: 10.1093/qjmed/hcq214 . PMID   21115460.
  32. Rodrigo, Malaka (9 October 2016). "Trials to start for home-grown anti-venom". The Sunday Times (Sri Lanka). Archived from the original on 20 July 2021. Retrieved 20 July 2021.
  33. Antiphospholipid Syndrome Archived 2006-11-17 at the Wayback Machine at SpecialtyLaboratories Archived 2019-04-02 at the Wayback Machine . Retrieved 27 September 2006.

Further reading