Snakes of Pakistan: Common Krait, Sindhi Krait, Northern Punjab Krait

Description and Biology:
The average length of this snake is 1.0 meters with a maximum lenght of 1.8 meters. It is moderately slender. Has a smooth. glossy appearance. The color varies. It can be blue-black, pale bluish-gray, steel blue, brown, uniformly black. There are paired narrow white, yellow, or grayish crossbands. Young specimens may have white spots instead of crossbands along first one-third of body. The underside is white. The head is egg-shaped, slightly distint from neck. The eyes are small, snout short, upper lip white or yellow and the tail is short with the tip pointed.

General characteristics:
The common Krait (Bungarus caeruleus) is a medium-sized snake, head barely distinguishable from neck; loreal scale absent; small dark eyes, round pupil, barely visible in life. Dorsum jet black to deep blue, which on preservation becomes dark : bluish luster. A series of 3—9 light vertebral spots followed by 38—56 paired narrow transverse bands. Supralabials and body ventrum white. Snout-vent length 1110-1125 mm, tail 145-157 mm.

The Sindhi Krait (Bungarus sindanus) has 17 midbody scale rows; ventrals 220-237, subcaudals 49-52. The dorsum is jet black, first light stripe appears at the level of 11 to 15th ventral. Snout-vent length 1029-1034 mm, tail 135-137 mm.

Sindhi Krait (Bungarus sindanus)
Photo Credit: Dr. Muhammad Sharif Khan

Biology:
This snake is nocturnal. It is very active and agile at night. It often hides in rodent holes, loose soil, beneath debris, so is rarely seen during day. When agitated, it will coil up with head concealed, body flattened, and make jerky movements. May also lift its tail. Reluctant to bite, but may make a quick snapping bite. Generally docile, unagressive during day, but may become aggressive during night. This is the most dangerous of Bunguarus species. The venom is highly toxic. It bites rarely, but in one study 77 percent of victims died.

Day/Night behavior changes have been reported in Bungarus caeruleus: during day it does not attempt to escape, instead rolls its body into a loose coiled ball, keeping its head well-concealed in the coil, while tail tip is kept upwards and is kept twisted. When touched, the ball flinches and hisses, with jerky movements. In "balled" condition, the snake allows considerable handling, however, over handling often instigates bite. At night the snake is very active, escapes by hissing loudly, or keeping still, occasionally biting the source of annoyance and tasnim, I986b).

This snake feeds on toads, frogs, snakes, lizards and mice, the kraits are known to be cannibalistic. Young are known to eat arthropods.

Habitat and Distribution:
The Kraits in Pakistan are found from coastal lowlands north and eastward to Waziristan and Quetta regions. Also found near southwestern Pakistan coast not far from Iran-Pakistan border. This snake is found in dry open plains, in termite mounds, in burrows of small rodents, beneath debris, at elevations as high as 1,700 meters. It needs ample water supply, so may be found in moist and wet areas such as wells or tanks containing water. Often found near or in human habitation.

The common Krait (Bungarus caeruleus) frequents open grasslands, semi-deserts with alluvial soil, are common in vegetation along tilled fields and extending into barns, farms, gardens. The light dark effect created during day under vegetation effectively camouflages the snake. It usually lives in holes and crevices in ground, however, when piles of cut vegetation, bricks, debris , etc., are at hand, it readily shelter under them. In Pakistan it has been reported from throughout Punjab, including alpine part, NWFP, Azad Kashmir, Sindh and southern Baluchistan. It is most common in Indus Valley.

The Sindhi Krait (Bungarus sindanus) is Deserticole, it inhabits mesic situations with sparse vegetation. In northwestern highland of Punjab, it has been collected from stony deserticole situations at an elevation of 300 m, close to badland cut into deep gullies on the slops of low hills. This habitat has only sparse grass with ocassional bushes. This specie has been reported from western Tharpakar, Bahawalpur and Bhawalnagar. The subspecies Bungarus s. razai has been reported from Mianwali and Makerwal, in northwestern Punjab, Pakistan. Recently an abnormal specimen is described from Goi, Kotli, Azad Kashmir (Khan, 1997).

Bungarus caeruleus ()
Bungarus sindanus (o)
Bungarus sindanus razai (x)

Map Credit: Dr. Muhammad Sharif Khan