Pseudocerastes
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 Field's horned viper, P. p. fieldi
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| Pseudocerastes persicus (Duméril, Bibron & Duméril, 1854) |
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Common names: Perisan horned viper, false horned viper.[2]
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 typical form described here.[4]
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[edit] 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]
[edit] 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]
[edit] 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]
[edit] 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.[5][2]
[edit] 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.[5][2]
[edit] Subspecies
| Species[4] | Authority[4] | Common name | Geographic range |
|---|---|---|---|
| P. p. fieldi | Schmidt, 1930 | Field's horned viper | Sinai Peninsula, southern Israel, Jordan, extreme northern Saudi Arabia and southwestern Iraq[2] |
| P. p. persicus | (Duméril, Bibron and Duméril, 1854) | Persian horned viper | North Iraq, south-east Turkey, Iran, southern Afghanistan, Pakistan and the mountains of Oman[2] |
These two subspecies are allopatric.[2]
[edit] Taxonomy
Some sources elevate P. p. fieldi to species level.[6]
[edit] Cited references
- ^ a b c McDiarmid 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).
- ^ a b c d e f g h i j k 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.
- ^ Pseudocerastes (TSN 634428). Integrated Taxonomic Information System. Accessed on 2 August 2006.
- ^ a b c Pseudocerastes persicus (TSN 634982). Integrated Taxonomic Information System. Accessed on 2 August 2006.
- ^ a b Spawls S, Branch B. 1995. The Dangerous Snakes of Africa. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. ISBN 0-88359-029-8.
- ^ Species Pseudocerastes fieldi at the EMBL Reptile Database
[edit] Other references
- Joger U. 1984. The venomous snakes of the Near and Middle East. Wiesbaden: Dr. Ludwig Reichert Verlag. 175 pp.
- Latifi M. 1991. The snakes of Iran. Published by the Dept. of the Environment and the Society for the Study of Amphibians and Reptiles, 2nd edition, 156 pp.
- Mendelssohn H. 1965. On the biology of venomous snakes of Israel. Part II. Israeli Journal of Zoology 14:185-212.
[edit] External links
- Species Pseudocerastes persicus at the EMBL Reptile Database
- Plumed Serpent - Sand Viper Page
