Echis carinatus

Taxobox
name = "Echis carinatus"

---

regnum = Animalia
phylum = Chordata
subphylum = Vertebrata
classis = Reptilia
ordo = Squamata
subordo = Serpentes
familia = Viperidae
subfamilia = Viperinae
genus = "Echis"
species = "E. carinatus"
binomial = "Echis carinatus"
binomial_authority = (Schneider, 1801)
synonyms = * ["Pseudoboa"] "Carinata" - Schneider, 1801
* "Boa Horatta" - Shaw, 1802
* "Scytale bizonatus" - Daudin, 1803
* ["Vipera" ("Echis")] "carinata" - Merrem, 1820
* ["Echis"] "zic zac" - Gray, 1825
* "Boa horatta" - Gray, 1825
* "Echis carinata" - Wagler, 1830
* "Vipera echis" - Schlegel, 1837
* "Echis" ("Echis") "carinata" - Gray, 1849
* "Echis ziczic" - Gray, 1849
* "V" ["ipera"] . "noratta" - Jerdon, 1854
* "V" ["ipera" ("Echis"] . "carinata" - Jan, 1859
* "Vipera" ("Echis") "superciliosa" - Jan, 1859
* "E" ["chis"] . "superciliosa" - Jan, 1863
* "Vipera Echis Carinata" - Higgins, 1873
* "Echis carinatus" - Boulenger, 1896
* "Echis carinata" var. "nigrosincta" - Ingoldby, 1923 (nomen nudum)
* "Echis carinatus carinatus" - Constable, 1949
* "Echis carinatus" - Mertens, 1969
* "Echis carinatus" - Latifi, 1978
* "Echis" [("Echis")] "carinatus carinatus" - Cherlin, 1990
* "Echis carinata carinata" - Das, 1996McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).] :"Common names: saw-scaled viper,Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Krieger Publishing Company, Malabar, Florida. 359 pp. ISBN 0-89464-877-2.] Indian saw-scaled viper, little Indian viper, [http://www.toxinfo.org/antivenoms/indication/ECHIS_CARINATUS.html "Echis carinatus" antivenoms] at [http://www.toxinfo.org/antivenoms/ Munich Antivenom Index] . Accessed 13 September 2006.] more.""Echis carinatus" is a venomous viper species found in parts of the Middle East and Central Asia, and especially the Indian subcontinent. It is the smallest of the Big Four dangerous snakes of India.Whitaker Z. 1990. Snakeman. Penguin Books Ltd. 192 pp. ISBN 0-14-014308-4.] Five subspecies are currently recognized, including the nominate subspecies described here.ITIS|ID=634967|taxon="Echis carinatus"|year=2006|date=1 August]

Description

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 supraocular is sometimes present. There are 9-14 interocular scales across the top of the head and 14-21 circumorbital scales. 1-3 rows of scales separate the eye and the supralabials. There are 10-12 supralabials, the fourth usually largest, and 10-13 sublabials.Boulenger GA. 1890. The Fauna of British India, Including Ceylon and Burma. Reptilia and Batrachia. Taylor & Francis, London, xviii, 541 pp.]

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.

The color-pattern consists of a pale buff, grayish, reddish, olive or pale brown ground color, overlaid middorsally with a series of variably colored, but mostly whitish spots, edged with dark brown, and separated by lighter interblotch patches. A series of white bows run dorsolaterally. The top of the head has a whitish cruciform or trident pattern and there is a faint stripe running from the eye to the angle of the jaw. The belly is whitish to pinkish, uniform in color or with brown dots that are either faint or distinct.

Common names

* English - saw-scaled viper, Indian saw-scaled viper, little Indian viper.
* Sinhala - "vali polonga". [http://www.slwcs.org/facts/snakes.html Checklists of the Snakes of Sri Lanka] at the [http://www.slwcs.org/ Sri Lanka Wildlife Conservation Society] . Accessed 15 August 2007.]
* Pashto - "phissi".Daniels,J. C. (2002) The Book of Indian Reptiles and Amphibians, BNHS & Oxford University Press, Mumbai, pp 151-153. ISBN 019-566099-4]
* Tamil - "surattai pambu". "viriyan pamboo", "surutai vireyan"
* Sindhi - "kuppur", "janndi".
* Marathi - "phoorsa".
* Kannada - "kallu have".
* Malayalam - "churuta"
* Gujarati - "tarachha", "zeri padkoo udaneyn".
* Hindi - "afai".
* Русский - "эфа песчанная" [http://www.floranimal.ru/pages/animal/je/1569.html ЭФА ПЕСЧАННАЯ] at [http://www.floranimal.ru/ Floranimal.ru] . Accessed 21 September 2008.]

Geographic range

Asia. On the Indian subcontinent: India, Sri Lanka Bangladesh and Pakistan (including Urak near Quetta and Astola Island off the coast of Makran). In the Middle East: Oman, Masirah (Island), eastern United Arab Emirates, Iraq and southwestern Iran. In Central Asia: Afghanistan, Uzbekistan, Turkmenistan and Tadzikhistan. The type locality was not included in the original description; given as "Arni" (India) by Russell (1796:3).

There are also reports that this species occurs in Iraq. [http://www.blackfive.net/main/2006/06/snakes_and_spid.html Snakes and Spiders] at [http://www.blackfive.net/ Black Five] . Accessed 6 January 2007.] Joint Chiefs of Staff Campaign Analysis Report, [http://www.brooks.af.mil/web/af/courses/amp/cluebag/Venomous Snakes & Scorpions in Iraq & Antivenin Sources.pdf Venomous Snakes and Scorpions in Iraq, and Their Antivenin Sources] at [http://www.brooks.af.mil/ 311th Human Systems Wing, Brooks City-Base] . Accessed 6 January 2007.]

Habitat

Found on a range of different substrates, including sand, rock, soft soil and in scrublands. Often found hiding under loose rocks. Specimens have also been found in Balochistan at altitudes of up to 1982 m.

Behavior

This species is mostly crepuscular and nocturnal, although there have been reports of activity during daylight hours. During the daytime they hide in all kinds of places, such as deep mammal burrows, rock fissures and fallen rotted logs. In sandy environments, they may bury themselves leaving only the head exposed. Often, they are most active after rains or on humid nights.Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.] 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 how some 20 individuals had massed on top of a single cactus or small shrub.

Its inconspicuousness nature, the speed of its strike, and its readiness to bite at the smallest provocation make this one of the most dangerous reptiles of India. Its characteristic pose, a double coil with a figure of eight, with the head poised in the center, permits it to lash out like a released spring. They move about mainly by sidewinding: a method at which they are considerably proficient and alarmingly quick. They are also capable of other forms of locomotion, but sidewinding seems to be best suited to moving about in their usual sandy habitats. It may also keep them from overheating too quickly, as there are only two points of contact with the hot surface in this form of locomotion.

In the northern parts of its range, these snakes hibernate in winter.

Feeding

It feeds on rodents, lizards, frogs, and a variety of arthropods, such as scorpions, centipedes and large insects. Diet may be varied according to availability of prey. High populations in some areas may be due to this generalist diet.

Reproduction

The population in India is ovoviviparous. In northern India, mating takes place in the winter with live young being born from April through August. Occasionally, births have also been recorded in other months. A litter usually consists of 3 to 15 young that are 115-152 mm in length. Mallow "et al." (2003) mention a maximum litter size of 23.

Venom

This species produces on the average of about 18 mg of dry venom by weight, with a recorded maximum of 72 mg. It may inject as much as 12 mg, whereas the lethal dose for an adult is estimated to be only 5 mg. Envenomation results in local symptoms as well as severe systemic symptoms that may prove fatal. Local symptoms include swelling and pain, which appear within minutes of a bite. In very bad cases the swelling may extend up the entire affected limb within 12-24 hours and blisters form on the skin.Ali G, Kak M, Kumar M, Bali SK, Tak SI, Hassan G, Wadhwa MB. 2004. Acute renal failure following echis carinatus (saw–scaled viper) envenomation. Indian Journal of Nephrology 14:177-181. [http://medind.nic.in/iav/t04/i4/iavt04i4p177.pdf#search=%22%22echis%20carinatus%22%20%2B%20envenomation%22 PDF] at [http://medind.nic.in/ Indian Medlars Centre] . Accessed 12 September 2006.] The venom yield from individual specimens varies considerably, as does the quantity injected per bite. About 20% of all bites are fatal.

Of the more dangerous systemic symptoms, hemorrhage and coagulation defects are the most striking. Hematemesis, melena, hemoptysis, hematuria and epistaxis also occur and may lead to hypovolemic shock. Almost all patients develop oliguria or anuria within a few hours to as late as 6 days post bite. In some cases, kidney dialysis is necessary due to acute renal failure (ARF), but this is not often caused by hypotension. It is more often the result of intravascular hemolysis, which occurs in about half of all cases. In other cases, ARF is often caused by disseminated intravascular coagulation.

In any case, antivenin therapy and intravenous hydration within hours of the bite are vital for survival. At least eight different polyvalent and monovalent antivenins are available against bites from this species.

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 simplistic in structure, which makes it easier to replicate. Indeed, it is obtained not only through the purification of whole venom, [https://www.sigmaaldrich.com/sigma/datasheet/E1518dat.pdf Echistatin from "Echis carinatus"] at [http://www.sigmaaldrich.com/ Sigma-Aldrich] . Accessed 29 September 2006.] but also as a product of chemical synthesis. [http://www.portfolio.mvm.ed.ac.uk/studentwebs/session2/group13/vipers.html Saw-scaled Vipers] at [http://www.portfolio.mvm.ed.ac.uk/ Electronic Medical Curriculum] . Accessed 29 September 2006.] Garsky VM, Lumma PK, Freidinger RM, Pitzenberger SM, Randall WC, Veber DF, Gould RJ, Friedman PA. 1989. Chemical synthesis of echistatin, a potent inhibitor of platelet aggregation from Echis carinatus: synthesis and biological activity of selected analogs. USA: Proc. Natl. Acad. Sci. Vol.86(11):4022–4026. [http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=287380&blobtype=pdf PDF] at [http://www.pubmedcentral.nih.gov/ PubMed Central] . Accessed 29 September 2006.] 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.Fabrizio MC. 2001. Use of Ecarin Clotting Time (ECT) with Lepirudin Therapy in Heparin-Induced Thrombocytopenia and Cardiopulmonary Bypass. JECT 33:117–125. [http://www.amsect.org/ce/HIT/ject_2001_v33_n2_fabrizio.pdf PDF] at [http://www.amsect.org/ Journal of The American Society of ExtraCorporeal Technology] . Accessed 5 June 2007.] [http://www.specialtylabs.com/books/display.asp?id=1060 Textarin/Ecarin Time] at [http://www.specialtylabs.com/ Specialty Laboratories] . Accessed 5 June 2007.] Yet another drug produced from "E. carinatus" venom is Aggrastat (Tirofiban).

ubspecies

ee also

* List of viperine species and subspecies
*
*
* Snakebite
* Sidewinding

References

Further reading

* 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. Frommani, Jena. 364 pp.

External links

*
* [http://itgmv1.fzk.de/www/itg/uetz/herp/photos/Echis_carinatus1.jpg"Echis carinatus" (image 1)] at the [http://itgmv1.fzk.de/ Institute of Toxicology and Genetics] . Accessed 12 September 2006.
* [http://itgmv1.fzk.de/www/itg/uetz/herp/photos/Echis_carinatus2.jpg"Echis carinatus" (image 2)] at the [http://itgmv1.fzk.de/ Institute of Toxicology and Genetics] . Accessed 12 September 2006.
* [http://itgmv1.fzk.de/www/itg/uetz/herp/photos/Echis_carinatus3.jpg"Echis carinatus" (image 3)] at the [http://itgmv1.fzk.de/ Institute of Toxicology and Genetics] . Accessed 12 September 2006.
* [http://members.fortunecity.com/ukp001/naja/viperidae/echis_carinatus.htm "Echis carinatus"] at [http://members.fortunecity.com/ukp001/naja/mainpage.htm Snakes of Sri Lanka] . Accessed 22 October 2006.
*