Daboia

Russell's Viper

Introduction

The genus Daboia contains the single species D. russelli, a viperid species responsible for a great many snakebites and fatalities.

Although fairly catholic in its diet (invertebrates as well as rodents are taken), with age Russell's Viper shows a preference for murid rodents (eg mice and rats), a key reason for it being found in the vicinity of human dwellings as well as paddy fields. It can be found in a wide range of habitats but not normally dense forest. The venom of the species is highly complex and toxic, and to complicate matters, may vary in composition among populations (O'Shea cites the example of problems caused by using imported Indian antivenom in Sri Lanka). Despite its fearsome reputation, Russell's Viper does provide a valuable service in controlling agricultural rodent pests.

Species	Common Name	Origin	Adult size	Notes
Daboia
D. russelli	Russell's Viper	Pakistan, India, Sri Lanka, Myanmar, Thailand, Indochina, Taiwan, Australasia (not New Zealand)	Avg 1.2m; up to 1.5m, max 1.67m	A sluggish species that becomes very dangerous if irritated. The hissing is louder than that of any other Indian snake. In addition to rodents, other mammals up to kitten size, lizards, frogs and small birds are taken; cannibalism known among the young. Scalation details:head covered in small scales, no shields. Dorsal scalation: 27-33 rows across midbody. Ventral scales: 153-180. Subcaudal scales: 41-64, divided. Other: body cylindrical and stocky, tapering at each end; head flat, triangular; short snout; nostrils large and open; pupil vertical; tail short Coloration: overall shade of brown; dorsal and lateral row of oval blotches or "lozenges", darker brown and outlined with black and then narrower white or buff line; dorsal blotches may coalesce while lateral blotches may be broken up; smaller spots may occur between dorsal and lateral rows; head has distinct patch to the rear; dark streak emarginated with pink, white or bluff behind eye; dark stripe from eye to lip; white, buff or pink line runs from gape to snout, the two lines forming a V shape above the snout; lips white, whiteish or pink; eyes gold flecked; ventrally white, whitish or yellowish, with a few dark half-moon marks on margins of anterior ventrals. Reproduction: 30-40 live young often produced, maximum of 63 but <20 or even a single individual are also known; young measure 21-26cm at birth. Birth takes place May-November, peaking June-July [SOURCE: Daniel, Das]
D. r. russelli	Indian Russell's Viper	Indian subcontinent
D. r. formosensis		Taiwan, China		These three subspecies are cited by the JCVI reptile database but do not seem to be recognised by other authorities. However Zhao and Adler recognise formosensis.
D. r. limitis
D. r. pulchella
D. r. siamensis	Siamese Russell's Viper, Indochinese Russell's Viper	E Thailand, Myanmar, S China, Taiwan, Indonesia (Java)		Found in open country up to 2,000m [Cox et al]. O'Shea suggests that it may warrant full specific status. Coloration: distinguished from Indian races by smaller dark spots between the lozenges: O'Shea describes the "Indochinese race" as being orange. [SOURCES: Cox et al, O'Shea, JCVI]

Bibliography

A Photographic Guide to Snakes and Other Reptiles of Peninsular Malysia, Singapore and Thailand, Merel J Cox, Peter Paul van Dijk, Jarujin Nabhitabhata, Kumthorn Thirakhupt, New Holland, 2006.

The Book of Indian Reptiles and Amphibians, J C Daniel, Bombay Natural History Society, Oxford University Press, Oxford, 2002.

Venomous Snakes of the World, Mark O'Shea, New Holland, 2008 edition. Useful overall guide to venomous snakes, few anatomical details but venom is briefly described for each species.

A Photographic Guide to Snakes and other Reptiles of India, Indraneil Das, New Holland UK, 2008. Handy pocket-sized guide to about half of India's reptile species.

Links

Wikipedia entry on D. russelli: one of the most informative on a snake I have seen.

The JCVI database entry contains full scalation details.