Echis carinatus, known as the Sindh saw-scaled viper, Indian saw-scaled viper, little Indian viper, and by other common names, is a viper species found in parts of the Middle East and Central Asia, and especially the Indian subcontinent. It is the smallest member of the "big four" Indian snakes that are responsible for causing the most snakebite cases and deaths, due to various factors including their frequent occurrence in highly populated regions, and their inconspicuous nature. Like all vipers, the species is venomous. Two subspecies are currently recognized, including the nominate subspecies described here.

Description

thumb|left|E. c. carinatus, southern India.

The size of E. carinatus ranges between in total length (body + tail), but usually no more than .

Scalation

Midbody there are 25–39 rows of dorsal scales that are keeled scales with apical pits; on the flanks, these have serrated keels. There are 143–189 ventral scales that are rounded and cover the full width of the belly. The subcaudals are undivided and number 21–52, and the anal scale is single.

  • Odia - Dhuli Naga.
  • Telugu - Chinna pinjara, pinjara
  • Sindhi - kuppur, janndi.
  • Iraqi Arabic - ḥayyat sayyid dakhīl (حية سيد دخيل)
  • Persian - mār-e ja'fari (مار جعفری)
  • Bengali - fursa boda sap (ফুরসা বোড়া সাপ), also কাঁটা-আঁইশা বোড়া, খুঁদে চন্দ্রবোড়া, বোড়া সাপ, বঙ্করাজ।
  • Tulu - netter mugel (ನೆತ್ತೆರ್ ಮೂಗೇಲ್)

Geographic range

Echis carinatus is endemic to Asia. On the Indian subcontinent it is found in India, Sri Lanka, Bangladesh, and Pakistan (including Urak near Quetta and Astola Island off the coast of Makran). In the Middle East it is found in Oman, Masirah (Island), eastern United Arab Emirates, Iraq, and southwestern Iran. In Central Asia it is found in Afghanistan, Uzbekistan, Turkmenistan, and Tajikistan.

The type locality was not included in the original description by Schneider (1801). However, a locality had been given as "Arni" (India) by Russell (1796:3).

It is found in Thiqar and Kirkuk governorates.

Habitat

thumb|Satara, Maharashtra|left

Echis carinatus is found on a range of different substrates, including sand, rock, soft soil and in scrublands. It is often found hiding under loose rocks. Specimens have also been found in Balochistan at altitudes of up to 1982 m. This species is often found climbing in bushes and shrubs, sometimes as much as 2 m above the ground. When it rains, up to 80% of the adult population will climb into bushes and trees. Once, it was observed that approximately 20 individuals had massed on top of a single cactus or small shrub. The venom yield from individual specimens varies considerably, as does the quantity injected per bite. The mortality rate from their bites is about 20%, and due to the availability of the anti-venom, deaths are currently quite rare.

The venom from this species is used in the manufacture of several drugs. One is called echistatin, which is an anticoagulant. Even though many other snake venoms contain similar toxins, echistatin is not only especially potent, but also simple in structure, which makes it easier to replicate. Indeed, it is obtained not only through the purification of whole venom, but also as a product of chemical synthesis. Another drug made from E. carinatus venom is called ecarin and is the primary reagent in the ecarin clotting time (ECT) test, which is used to monitor anticoagulation during treatment with hirudin. Yet another drug produced from E. carinatus venom is Aggrastat (Tirofiban).

Subspecies

{|cellspacing=0 cellpadding=2 border=1 style="border-collapse: collapse;"

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! style="background:#f0f0f0;"|Subspecies

|Peninsular India.

|-

|E. c. sochureki

|Stemmler, 1969

|Sochurek's saw-scaled viper

|Southern Afghanistan, Pakistan, northern India, southern and central Iran, Oman and UAE.

|}

References

Further reading

  • Boulenger GA (1896). Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the ... Viperidæ. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I.- XXV. (Echis carinatus, pp. 505–507).
  • Das I (2002). A Photographic Guide to Snakes and other Reptiles of India. Sanibel Island, Florida: Ralph Curtis Books. 144 pp. . (Echis carinatus, p. 61).
  • Hughes B (1976). "Notes on African carpet vipers, Echis carinatus, Echis leucogaster and Echis ocellatus (Viperidae, Serpentes)". Rev. suisse Zool. 83 (2): 359-371.
  • Schneider JG (1801). Historiae Amphibiorum naturalis et literariae Fasciculus Secundus continens Crocodilos, Scincos, Chamaesauras, Boas, Pseudoboas, Elapes, Angues, Amphisbaenas et Caecilias. Jena: F. Frommann. vi + 374 pp. + Plates I-II. (Pseudoboa carinata, new species, pp. 285–286). (in Latin).
  • Smith MA (1943). The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-region. Reptilia and Amphibia. Vol. III.—Serpentes. London: Secretary of State for India. (Taylor and Francis, printers). xii + 583 pp. (Echis carinatus, pp. 487–490, Figure 154).
  • Wall F (1921). Ophidia Taprobanica or the Snakes of Ceylon. Colombo, Ceylon [Sri Lanka]: Colombo Museum. (HR Cottle, Government Printer). xxii + 581 pp. (Echis carinatus, pp. 531–546, Figures 93-95).
  • Echis carinatus at Snakes of Sri Lanka. Accessed 22 October 2006.