Cerastes cerastes
| Cerastes cerastes | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scientific classification | ||||||||||||||||||||
| ||||||||||||||||||||
| Binomial name | ||||||||||||||||||||
| Cerastes cerastes (Linnaeus, 1758) | ||||||||||||||||||||
| Synonyms | ||||||||||||||||||||
|
Cerastes cerastes is a venomous viper species native to the deserts of Northern Africa and parts of the Middle East. They are ore often easily recognized by the presence of a pair of supraocular horns, although hornless individuals do occur.[2] No subspecies are currently recognized.[3]
Common names: Saharan horned viper, [2] Sahara horned viper,[4] horned desert viper.[5]
Description
The 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 eyes are prominent and set on the side of the head.[4] There is significant sexual dimorphism, with males having larger heads and larger eyes than females. Compared to C. gasperetti, the relative head size of C. cerastes is larger and there is a greater frequency of horned individuals (13% versus 48% respectively).[2][6]
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][4]
Geographic range
Found in arid 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]
Habitat
Favors 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]
Behavior
They 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]
Reproduction
In 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.[4]
Venom
C. 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[4]. 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] An estimated lethal dose for humans is 40-50 mg[4].
Taxonomy
A number of subspecies may be encountered in literature:[2]
- C. c. hoofieni - Werner & Sivan, 1999 - Saudi Arabia.
- C. c. karlhartli - Sochurek, 1974 - South-east Egypt and Sinai Peninsula.
- C. c. mutila - Domergue, 1901 - South-west Algeria, Morocco.
Previously, C. gaperettii was also regarded as a subspecies of C. cerastes.[2]
Attribution
- Some content on this page may previously have appeared on Wikipedia.
Cited references
- ↑ 1.0 1.1 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).
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Krieger Publishing Company. 359 pp. ISBN 0-89464-877-2.
- ↑ Cerastes cerastes (TSN 634963) at Integrated Taxonomic Information System. Accessed 27 March 2007.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Spawls S, Branch B. 1995. The Dangerous Snakes of Africa. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. ISBN 0-88359-029-8.
- ↑ Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
- ↑ Werner YL, Verdier A, Rosenman D, Sivan N. 1991. Systematics and zoogeography of Cerastes (Ophidia: Viperidae) in the Levant: 1, Distinguishing Arabian from African "Cerastes cerastes." The Snake 23:90-100.
Other references
- Calmette A. 1907. Les venins, les animaux venimeux et la serotherapie antivenimeuse. In: Bucherl W. editor. 1967. Venomous Animals and Their Venoms. Vol. I. Paris: Masson. pp 233.
- Mohamed AH, Kamel A, Ayobe MH. 1969. Studies of phospholipase A and B activities of Egyptian snake venoms and a scorpion venom. Toxicon 6:293-8.
- Joger U. 1984. The Venomous Snakes of the Near and Middle East. Wiesbaden: Dr. Ludwig Reichert Verlag. 175 pp.
- Labib RS, Malim HY, Farag NW. 1979. Fractionation of Cerastes cerastes and Cerastes vipera snake venoms by gel filtration and identification of some enzymatic and biological activities. Toxicon 17:337-45.
- Labib RS, Azab MH, Farag NW. 1981. Effects of Cerastes cerastes (Egyptian sand viper) snake venoms on blood coagulation: separation of coagulant and anticoagulant factors and their correlation with arginineesterase protease activities. Toxicon 19:85-94.
- Labib RS, Azab ER, Farag NW. 1981. Proteases of Cerastes cerastes and Cerastes vipera snake venoms. Toxicon 19:73-83.
- Schnurrenburger H. 1959. Observations on behavior in two Libyan species of viperine snake. Herpetologica 15:70-2.
- U.S. Navy. 1991. Poisonous Snakes of the World. New York: Dover Books. (Reprint of US Govt. Printing Office, Washington D.C.) 133 pp. ISBN 0-486-26629-X.