Bitis caudalis
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| Bitis caudalis (Smith, 1839) |
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Common names: horned adder,[2][3] horned puff adder.[4]
Bitis caudalis is a venomous viper species found in the arid region of south-west Africa. Easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized.[5]
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[edit] Description
A short and stout little viper that usually averages 30-40 cm in length. The largest specimen reported is a female from southern Botswana measuring 51.5 cm.[2]
[edit] Geographic range
The arid region of south-west Africa: south-west Angola, Namibia, across the Kalahari Desert of southern Botswana, into northern Transvaal and southwestern Zimbabwe. In South Africa it is found from the northern Cape Province south to the Great Karoo. Type locality: "... the sandy districts north of the Cape Colony..." [South Africa].[1]
[edit] Habitat
Mostly found in sparsely-vegetated desert and semi-arid scrub country.[2]
[edit] Venom
Bites are assumed to be rare and no epidemiological information is available.[4]
Little information is available regarding the toxicity and amount of venom produced. Spawls and Branch (1995) report an average yield of 85 mg of wet venom,[2] while Christensen (1971) offers an LD50 value of 1.2 mg/kg IV.[6]
Based on this LD50 value, Spawls and Branch (1995) estimated that about 300 mg of this venom would be required to kill an adult. They regard this venom as one of the weakest of the genus.[2] On the other hand, an older report by the U.S. Navy (1965, 1991) suggests that it is highly toxic and that a number of deaths have occurred as a result.[7][8] According to Broadley and Cock (1975), envenomation symptoms in humans include swelling, severe pain, nausea, vomiting and shock. Blisters and necrotic ulcers may form around the bite site.[4]
No antivenins are available to give protection against this particular species.[2] According to the U.S. Navy (1965, 1991),[7][8] polyvalent antivenins produced by SAMIR and the Pasteur Institute are said to be effective, while Mallow et al. (2003) report that currently available antivenins are of limited effectiveness.[4]
Viljoen et al. (1982) isolated a protein, a neurotoxic phospholipase A2, from the venom, which they called "caudoxin". According to Lee et al. (1983), this is a presynaptic toxin similar to bungarotoxin, but with different binding sites.[4]
[edit] Taxonomy
A number of authors, including Mertens (1955), use a trinomial to refer to this species, even though no subspecies are recognized.[1]
[edit] See also
[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 Spawls S, Branch B. 1995. The Dangerous Snakes of Africa. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. ISBN 0-88359-029-8.
- ^ Species Bitis caudalis at the EMBL Reptile Database
- ^ a b c d e 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.
- ^ Bitis caudalis (TSN 634951). Integrated Taxonomic Information System. Accessed on 25 July 2006.
- ^ Brown JH. 1973. Toxicology and Pharmacology of Venoms from Poisonous Snakes. Springfield, Illinois: Charles C. Thomas. 184 pp. LCCCN 73-229. ISBN 0-398-02808-7.
- ^ a b U.S. Navy. 1965. Poisonous Snakes of the World. US Govt. Printing Office, Washington D.C. 212 pp.
- ^ a b U.S. Navy. 1991. Poisonous Snakes of the World. US Govt. New York: Dover Publications Inc. 203 pp. ISBN 0-486-26629-X.
[edit] Other references
- Broadley DG, Cock EV. 1975. Snakes of Rhodesia. Zimbabwe: Longman Zimbabwe Ltd. 126 pp. ASIN B0006CM8SE.
- Christensen PA. 1971. The venoms of Central and South Africa. In Venomous Animals and Their Venoms, Vol I, by Bücherl W, Deulofeu V, Buckley EE. New York: Academic Press. pp. 437-462. ISBN 0121389022.
- Viljoen CC, Botes DP, Kruger H. 1982. Isolation and characterization of the animo acid sequence of caudoxin, a presynaptic acting toxic phospholipase A2 from the venom of the horned puff adder (Bitis caudalis). Toxicon 20(4):715-37.
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