Pseudocerastes

Common names: Persian horned viper, false horned viper,^[2] more.

Pseudocerastes is a monotypic genus created for a venomous viper species, P. persicus.^[3] This species is found throughout the Middle East and as far east as Pakistan, but not on the African mainland. Often referred to as the false horned viper because of the hornlike structures above their eyes that are made up of numerous small scales. This is in contrast to the "true" horned viper, Cerastes cerastes, that has similar supraorbital horns that consist of a single elongated scale.^[2] Two subspecies are currently recognized, including the nominate subspecies described here.^[4]

Additional recommended knowledge

Essential Laboratory Skills Guide

Weighing the right way

Guide to balance cleaning: 8 simple steps

Description

Averages between 40 to 70 cm in length, with a maximum of 108 cm being reported. Females are usually larger than males. These snakes can attain a considerable weight relative to their size, with specimens sometimes exceeding 500 gr.^[2]

The head is broad, flat, distinct from the neck and covered with small, imbricate scales. The snout is short and rounded. The nostrils are positioned dorsolaterally and have valves. The nasal scale is unbroken. The rostral scale is small and wide. The eyes are small to average in size. There are 15-20 interocular scales and 15-20 circumorbitals. The supraorbital hornlike structures above each eye consisting of small, imbricate scales and are also present in juveniles. There are 11-14 supralabials and 13-17 sublabials. 2-4 rows of small scales separate the supralabial scales from the suboculars.^[2]

The body is covered with weakly to strongly keeled dorsal scales. On many of these, the keel terminates before the end of the scale and forms a bump. Many others form a point. At midbody, there are 21-25 scale rows, none of them oblique. There are 134-163 ventral scales and 35-50 paired subcaudals. The tail is short.^[2]

Common names

Persian horned viper, false horned viper,^[2] Persian horned desert viper,^[5] eye-horned viper.^[6]

Geographic range

The Sinai of Egypt, Israel, Jordan, northern Saudi Arabia, the mountains of Oman, northern and northwestern Iraq, possibly southern Syria, extreme southeastern Turkey, northwestern Azerbaijan, Iran and Pakistan to the borders of Afghanistan. The type locality is listed as "Perse" (Persia).^[1]

Behavior

These snakes are generally rather slow-moving and may employ various methods of locomotion, including sidewinding, serpentine and rectilinear. These snakes are almost totally nocturnal, only being seen during the day or early evening during colder periods. It is not particularly aggressive, but will hiss loudly when disturbed. It is not capable of sinking into the sand vertically like Cerastes.^[2]

Reproduction

Pseudocerastes is oviparous and lays 11-21 eggs. When produced, these already contain well-developed embryos than can be as much as 8.5 cm long. As a result, they hatch after only 30-32 days at 31 °C and then measure 14.0 to 16.2 cm in length. They do well in captivity and are relatively easy to breed.^[7][2]

Venom

P. p. persicus venom exhibits strong hemorrhagic activity typical of most vipers. No antivenin is available for bites from this subspecies, although it is reported that a polyvalent antiserum does offer some protection.^[7][2]

Subspecies

These two subspecies are allopatric.^[2]

Taxonomy

Some sources elevate P. p. fieldi to species level.^[8]

In 2006, Bostanchi, Anderson, Kami and Papenfuss described a new species: P. urarachnoides. It is found in the Zagros mountains of western Iran and is described as having the most elaborate tail ornamentation of any snake yet described, save for the rattlesnakes, Crotalus and Sistrurus.^[9]

See also

• List of viperine species and subspecies
• Viperinae by common name
• Viperinae by taxonomic synonyms
• Snakebite

References

Further reading