Saw-scaled viper

Appearance

Size ranges between 38 and 80 cm in total 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 from the supralabials. There are 10-12 supralabials, the fourth usually largest, and 10-13 sublabials.

Naming

* English - saw-scaled viper, Indian saw-scaled viper, little Indian viper.
⤷  Sinhala - ''vali polonga''.
⤷  Oriya - ''Dhuli Naga''.
⤷  Pushtu - ''phissi''.
⤷  Tamil - ''surattai pambu''. ''viriyan pamboo'', ''surutai vireyan''
⤷  Telugu - ''Chinna pinjara'', ''thoti pinjara''
⤷  Sindhi - ''kuppur'', ''janndi''.
⤷  Marathi - ''phoorsa'[फुरसं]''.
⤷  Kannada - ''kallu have''.
⤷  Malayalam - ''anali''
⤷  Gujarati - ''tarachha'', ''zeri padkoo udaneyn''.
⤷  Hindi - ''aphai''
⤷  Russian - ''эфа песчаная''
⤷  Iraqi Arabic- Said Dekhil snake حية سيد دخيل
⤷ Persian : Jafaree snake مار جعفری

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. 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.

They are one of the species responsible for causing the most snakebite cases due to their inconspicuous nature. 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.

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.

Reproduction

The population in India is ovoviparous. 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.'' mention a maximum litter size of 23.

Food

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.

Defense

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. 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.