Африкалық құмдық жыланның сипаттамасы

Species of highly venomous snake
the viper species "common puff adder", native to Africa

The puff adder (Bitis arietans) is a highly venomous viper species found in savannahs and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rainforest regions. It is responsible for causing the most snakebite fatalities in Africa owing to various factors, such as its wide distribution, frequent occurrence in highly populated regions, and aggressive disposition. Like all other vipers, it is venomous. Two subspecies are currently recognized, including the nominate subspecies described here. The species is commonly known as the puff adder, African puff adder, or common puff adder.

German naturalist Blasius Merrem described the puff adder in 1820. The word arietans means "striking violently" and is derived from the Latin arieto. The type locality given is "Promontorio bonae spei" (Cape of Good Hope), South Africa.

The head has a less than triangular shape with a blunt and rounded snout. Still, the head is much wider than the neck. The rostral scale is small. The circumorbital ring consists of 10–16 scales. Across the top of the head, there are 7–11 interocular scales; three or four scales separate the suboculars and the supralabials. It has 12 to 17 supralabials and 13–17 sublabials. The first three or four sublabials contact the chin shields, of which only one pair exists. Often, two fangs are on each maxilla, and both can be functional. It is not found in rainforest areas, such as along the coast of West Africa and in Central Africa (i. e., central DR Congo); it is also absent from the Mediterranean coastal region of North Africa. On the Arabian Peninsula, it is found as far north as Ta'if.

Normally a sluggish species, the puff adder relies on camouflage for protection. Locomotion is primarily rectilinear, using the broad ventral scales in a caterpillar fashion and aided by its own weight for traction. When agitated, it can resort to a typical serpentine movement of surprising speed.

Females produce a pheromone to attract males, which engage in neck wrestling combat dances. A female in Malindi was followed by seven males. and is one of the most toxic of any vipers based on LD50. Mallow et al. (2003) give an LD50 range of 1.0–7.75 mg/kg SC. Venom yield is typically 150–350 mg, with a maximum of 750 mg. Serious bites cause limbs to become immovably flexed as a result of significant hemorrhage or coagulation in the affected muscles. Residual induration, however, is rare and usually these areas completely resolve. Most fatalities are associated with poor clinical management and neglect.