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Cerastes cerastes
Cerastes cerastes is a venomous viper species native to the deserts of Northern Africa and parts of the Middle East. They often are easily recognized by the presence of a pair of supraocular horns, although hornless individuals do occur.[2] No subspecies are currently recognized.[4] Additional recommended knowledge
DescriptionThe average length is 30-60 cm, with a maximum of 85 cm. Females are larger than males.[2] One of the most distinctive characteristics of this species are the supraorbital horns, one over each eye. However, these are either present, reduced in size or absent (see Cerastes).[2] The color pattern consists of a yellowish, pale gray, pinkish or pale brown ground color that almost always matches the substrate color where the animal is found. Dorsally, a series of dark, semi-rectangular blotches run the length of the body. These may or may not be fused into crossbars. The belly is whitish and the tail may have a black tip.[2][5] Common namesSaharan horned viper, [2] horned desert viper,[3] Sahara horned viper,[5] desert horned viper, North African horned viper,[6] African desert horned viper, greater cerastes,[7] asp, horned viper.[8] Geographic rangeArid north Africa (Morocco, Western Sahara, Mauritania and Mali, eastward through Algeria, Tunisia, Niger, Libya and Chad to Egypt, Sudan, Ethiopia and Somalia) through Sinai to the northern Negev of Israel. In the Arabian Peninsula, it occurs in Yemen and extreme southwestern Saudi Arabia, where it is sympatric with C. gaperettii. A report of this species being found in Lebanon is unlikely, according to Joger (1984). Originally, the type locality was listed only as "Oriente." However, Flower (1933) proposed "Egypt" by way of clarification.[1] HabitatFavors dry sandy areas with sparse rock outcroppings. Tends not to prefer coarse sand. Occasionally found around oases and up to an altitude of 1500 m. Prefers coolers temperatures with annual averages of 20°C or less.[2] BehaviorThey typically move about by sidewinding, but instead of sliding sideways on the sand, they press their weight into it leaving whole-body impressions. Often, it is even possible to use these impressions to make ventral scale counts. They have a reasonably placid temperament, but if threatened they may assume a C-shaped posture rapidly rub their coils together. Having strongly keeled scales, this produces a rasping noise, similar to Echis. They are capable of striking quickly.[2] ReproductionIn captivity, mating was observed in April and always occurred while the animals were buried in the sand.[2] This species is oviparous, laying 8-23 eggs that hatch after 50 to 80 days of incubation. The eggs are laid under rocks and in abandoned rodent burrows. The hatchlings measure 12-15 cm in length.[5] VenomC. cerastes venom is not very toxic, although it is reported to be similar in action to Echis venom.[2] Envenomation usually causes swelling, hemorrhage, necrosis, nausea, vomiting and hematuria. A high phospholipase A2 content may cause cardiotoxicity and myotoxicity[5]. Studies of venom from both C. cerastes and C. vipera list a total of eight venom fractions, the most powerful of which has hemorrhagic activity. Venom yields vary, with anything from 19-27 mg dried venom to 100 mg being reported.[2] For venom toxicity, Brown (1973) gives LD50 values of 0.4 mg/kg IV and 3.0 mg/kg SC.[6] An estimated lethal dose for humans is 40-50 mg[5]. TaxonomyA number of subspecies may be encountered in literature:[2]
Previously, C. gaperettii was also regarded as a subspecies of C. cerastes.[2] See also
References
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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Cerastes_cerastes". A list of authors is available in Wikipedia. |