Overview
Bitis is a genus of venomous vipers found in Africa and the southern Arabian Peninsula.1] It includes the largest and the smallest vipers in the world. Members are known for their characteristic threat displays that involve inflating and deflating their bodies while hissing and puffing loudly.[2] The type species for this genus is B. arietans,[1] which is also the most widely distributed viper in Africa.[3] Currently, 14 species are recognized.[4]
Members of the genus are commonly known as African adders,[2] African vipers,[3] or puff adders.
Description
Size variation within this genus is extreme, ranging from the very small B. schneideri, which grows to a maximum of 28 cm and is perhaps the world's smallest viperid, to the very large B. gabonica, which can attain a length of over 2 m and is the heaviest viper in the world.[2]
All have a wide, triangular head with a rounded snout, distinct from the neck, and covered in small, keeled, imbricate scales. The canthus is also distinct. A number of species have enlarged rostral or supraorbital scales that resemble horns. Their eyes are relatively small. They have large nostrils that are directed outwards and/or upwards. Up to six rows of small scales separate the rostral and nasal scales. All species have a well-developed supranasal sac. The fronts of the maxillary bones are very short, supporting only one pair of recurved fangs.[2][5]
These snakes are moderately to extremely stout. Their bodies are covered with keeled scales that are imbricate with apical pits. At midbody, the dorsal scales number 21-46. Laterally, the dorsal scales may be slightly oblique. The ventral scales, which number 112-153, are large, rounded and sometimes have slight lateral keels. Their tails are short. The anal scale is single. The paired subcaudal scales number 16-37 and are sometimes keeled laterally.[2][5]
Geographic range
Puff adders are found in Africa and the southern Arabian Peninsula.[1]
Behavior
Bitis species are known for their behavior of inflating and deflating their bodies in loud hissing or puffing threat displays. They are terrestrial ambush predators, and appear sluggish, but can strike with amazing speed.[2] In contrast to the pitvipers of the subfamily Crotalinae, Bitis species appear to lack heat-sensitive organs and showed no differences in their behavior in laboratory tests towards warm and cool objects that mimicked prey.[6][7]
Reproduction
All members are viviparous and some give birth to large numbers of offspring.
Venom
All members of this genus are dangerous ? some extremely so.[2] At least six different polyvalent antivenoms are available. Five are produced by Aventis Pasteur (France), Pasteur Merieux (France) and SAIMR (South Africa). All of these specifically protect against B. arietans and four also cover B. gabonica.[8][9] At least one protects specifically against bites from B. nasicornis: India Antiserum Africa Polyvalent.[10] In the past, such antivenoms have been used to treat bites from other Bitis species, but with mixed r esults.[2]
Species
*) Not including the nominate subspecies.
T) Type species.
Taxonomy
Other species may be encountered in literature, such as:[2]
- B. albanica - Hewitt, 1937
- B. armata - Smith, 1826
Lenk et al. (1999) used molecular data (immunological distances and mitochondrial DNA sequences) to estimate the phylogenetic relationships among species of Bitis. They identified four major monophyletic groups for which they created four subgenera:[2]
- Bitis - B. arietans
- Calechidna - B. albani ca, B. armata, B. atropos, B. caudalis, B. cornuta, B. heraldica, B. inorata, B. peringueyi, B. rubida, B. schneideri, B. xeropaga
- Macrocerastes - B. gabonica, B. nasicornis, B. parviocula
- Keniabitis - B. worthingtoni
For now, this division is of little consequence as far as the nomenclature is concerned. However, the definition of subgenera within a genus is often the sign of an impending split. Therefore, those interested in these snakes would do well to familiarize themselves with these new subgenera.[2]
See also
- List of viperine species and subspecies
- Viperinae by common name
- Viperinae by taxonomic synonyms
- Snakebite
- B. albanica - Hewitt, 1937
- B. arma ta - Smith, 1826
Lenk et al. (1999) used molecular data (immunological distances and mitochondrial DNA sequences) to estimate the phylogenetic relationships among species of Bitis. They identified four major monophyletic groups for which they created four subgenera:[2]
- Bitis - B. arietans
- Calechidna - B. albanica, B. armata, B. atropos, B. caudalis, B. cornuta, B. heraldica, B. inorata, B. peringueyi, B. rubida, B. schneideri, B. xeropaga
- Macrocerastes - B. gabonica, B. nasicornis, B. parviocula
- Keniabitis - B. worthingtoni
For now, this division is of little consequence as far as the nomenclature is concerned. However, the definition of subgenera within a genus is often the sign of an impending split. Therefore, those interested in these snakes would do well to familiarize themselves with these new subgenera.[2]
See also
- List of viperine species and subspecies
- Viperinae by common name
- Viperinae by taxonomic synonyms
- Snakebite
References
- ^ a b c d e f g Mc Diarmid RW, Campbell JA, Tour? 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).[page needed]
- ^ a b c d e f g h i j k l 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.[page needed]
- ^ 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.[page needed]
- ^ a b "Bitis". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=634420. Retrieved 18 July 2006.
- ^ a b U.S. Navy. 1965. Poisonous Snakes of the World. US Govt. Printing Office, Washington D.C. 212 pp.[page needed]
- ^ Safer, Adam B; Grace, Michael S (2004). "Infrared imaging in vipers: Differential responses of crotaline and viperine snakes to paired thermal targets". Behavioural Brain Research 154 (1): 55?61. doi:10.1016/j.bbr.2004.01.020. PMID 15302110.
- ^ Krochmal, Aaron R.; Bakken, George S.; LaDuc, Travis J. (2004). "Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)". Journal of Experimental Biology 207 (24): 4231?8. doi:10.1242/jeb.01278. PMID 15531644.
- ^ Bitis arietans antivenoms at Munich AntiVenom INdex. Accessed 25 August 2006.
- ^ Bitis gabonica antivenoms at Munich AntiVenom INdex. Accessed 25 August 2006.
- ^ Miami-Dade Fire Rescue Venom Response Unit at VenomousReptiles.org. Accessed 5 September 2006.
- ^ Largen, M., and Spawls, S. 2010. The Amphibians and Reptiles of Ethiopia and Eritrea. Edition Chimara: Frankfurt am Main. ISBN 978-3-89973-466-9[page needed]
Taxonomy
The Genus Bitis is further organized into finer groupings including:
- Species: ZipcodeZoo has pages for 37 species and subspecies in the Genus Bitis: B. albanica · B. arientans · B. arietans (African Puff Adder) · B. arietans arietans (African Puff Adder) · B. arietans somalica · B. arietaus · B. armata · B. atrapos · B. atropos (Mountain Adder) · B. atropos atropos (Mountain Adder) · B. atropos unicolor · B. caudalis (Horned Puff Adder) · B. caudalis paucisquamatus · B. cornuta (Many-Horned Adder) · B. rubida · B. rubida (Many-Horned Adder) · B. gabonica (Gaboon Viper) · B. gabonica gabonica (Gaboon Adder) · B. gabonica nasicornis · B. gabonica rhinoceros · B. heraldica (Angolan Adder; Bocage's Horned Adder (After Frank & Ramus 1995).) · B. hindii · B. inornata (Plain Mountain Adder) · B. lachesis · B. nasicanis · B. nasicornis (Rhinoceros Adder) · B. nassicornis · B. parviocula (Ethiopian Mountain Adder) · B. peringreyi · B. peringueyi (Side-Winding Adder) · B. rhinoceros · B. rubida (Red Adder) · B. schneideri (Namaqua Dwarf Adder) · B. superciliaris · B. wasicornis · B. worthingtoni (Kenya Horned Viper) · B. xeropaga (Desert Mountain Adder)
References
- ^ a b c d e f g McDiarmid RW, Campbell JA, Tour? 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).[page needed]
- ^ a b c d e f g h i j k l 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.[page needed]
- ^ 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.[page needed]
- ^ a b "Bitis". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=634420. Retrieved 18 July 2006.
- ^ a b U.S. Navy. 1965. Poisonous Snakes of the World. US Govt. Printing Office, Washington D.C. 212 pp.
- ^ Safer, Adam B; Grace, Michael S (2004). "Infrared imaging in vipers: Differential responses of crotaline and viperine snakes to paired thermal targets". Behavioural Brain Research 154 (1): 55?61. doi:10.1016/j.bbr.2004.01.020. PMID 15302110.
- ^ Krochmal, Aaron R.; Bakken, George S.; LaDuc, Travis J. (2004). "Heat in evolution's kitchen: evolutionary perspectives on the functions and origin of the facial pit of pitvipers (Viperidae: Crotalinae)". Journal of Experimental Biology 207 (24): 4231?8. doi:10.1242/jeb.01278. PMID 15531644.
- ^ Bitis arietans antivenoms at Munich AntiVenom INdex. Accessed 25 August 2006.
- ^ Bitis gabonica antivenoms at Munich AntiVenom INdex. Accessed 25 August 2006.
- ^ Miami-Dade Fire Rescue Venom Response Unit at VenomousReptiles.org. Accessed 5 September 2006.
- ^ Largen, M., and Spaw ls, S. 2010. The Amphibians and Reptiles of Ethiopia and Eritrea. Edition Chimara: Frankfurt am Main. ISBN 978-3-89973-466-9[page needed]
Further Reading
- Branch, William R (1999). "Dwarf adders of the Bitis cornuta-inornata complex (Serpentes: Viperidae) in Southern Africa". Kaupia Darmst?dter Beitr?ge zur Naturgeschichte 8: 39?63.
- Dum?ril A-M-C, Bibron G. 1844. Erpetologie G?n?rale ou Histoire Naturelle Complete des Reptiles. Vol.6. Librarie Encyclop?dique de Roret, Paris. 609 pp.[60].
- Gray JE. 1842. Monographic Synopsis of the Vipers, or the Family Viperid?. Zoologcal Miscellany, London, 2: 68-71.[69].
- Laurenti J.N. 1768. Specimen medicum, exhibens synopsin reptilium emendatum cum experimentis circa Venena et antidota reptilium Austriacorum. J.T. de Trattern, Wien. 214 pp.[103].
- Lenk, Peter; Herrmann, Hans-Werner; Joger, Ulrich; Wink, Michael (1999). "Phylogeny and taxonomic subdivision of Bitis (Reptilia: Viperidae) based on molecular evidence". Kaupia Darmst?dter Beitr?ge zur Naturgeschichte 8: 31?38.
- Merrem B. 1820. Versuch eines sy stems der amphibien. Tentamen systematis amphibiorum. J.C. Krieger, Marburg. xv, 191 pp.[150], 1 pl.
- Reuss T. 1939. Zeitschrift Aquarien und Terrarien Vereine. Berlin. (1):14[14].
- U.S. Navy. 1991. Poisonous Snakes of the World. New York: Dover Books. (Reprint of US Govt. Printing Office, Washington D.C.) 232 pp. ISBN 0-486-26629-X.
External links
- Bitis at the Reptarium.cz Reptile Database. Accessed 2 August 2007.
- Southern adder (Bitis armata) at ARKive. Accessed 5 October 2006.
Sources
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