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Venomous Snake
Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or grooved fangs, although some venomous snakes lack well-developed fangs. Common venomous snakes include the families Elapidae, Viperidae, Atractaspididae, and some of the Colubridae. The toxicity of venom is mainly indicated by murine , while multiple factors are considered to judge the potential danger to humans. Other important factors for risk assessment include the likelihood that a snake will bite, the quantity of venom delivered with the bite, the efficiency of the delivery mechanism, and the location of a bite on the body of the victim. Snake venom may have both neurotoxic and hemotoxic properties. There are about 600 venomous snake species in the world. Evolution The evolutionary history of venomous snakes can be traced back to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Evolution
Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure.Zhang, J. and Kumar, S. 1997Detection of convergent and parallel evolution at the amino acid sequence level. ''Mol. Biol. Evol.'' 14, 527-36. Parallel vs. convergent evolution Given a particular trait that occurs in each of two lineages descended from a specified ancestor, it is possible in theory to define parallel and convergent evolutionary trends strictly, and distinguish them clearly from one another. However the criteria for defining convergent as opposed to parallel evolution often are unclear in practice, so that arbitrary diagnosis is common in some cases. When two species are similar in a particular character, evolution is defined as parallel if the ancestors shared that similarity; if they did not, the evolution of that character in those species is defined as convergent. However, thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Snake
Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, whereas Laticaudinae only includes the sea kraits (''Laticauda''), of which three species are found exclusively in freshwater. If these three freshwater species are excluded, there are 69 species of sea snakes divided between seven genera. Most sea snakes are venomous, except the genus ''Emydocephalus'', which feeds almost exclusively on fish eggs. Sea snakes are extensively adapted to a fully aquatic life and are unable to move on land, except for the sea kraits, which have limited land movement. They are found in warm coastal waters from the Indian Ocean to the Pacific and are closely related to venomous terrestrial snakes in Australia. All sea snakes have paddle-like tails and many have laterally compressed bodies that give them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boomslang
The boomslang (, , or ; ''Dispholidus typus'') is a large, highly venomous snake in the family Colubridae. Taxonomy and etymology Its common name means "tree snake" in Afrikaans and Dutch – ''boom'' meaning "tree", and ''slang'' meaning "snake". In Afrikaans, the name is pronounced . The boomslang is thought to be closely related to members of the genera '' Thelotornis'', ''Thrasops'', '' Rhamnophis'', and '' Xyelodontophis'', with which it forms the taxonomic tribe Dispholidini. Subspecies Two subspecies are recognized, including the nominotypical subspecies. * ''D. t. kivuensis'' * ''D. t. typus'' The trinomial authority in parentheses for ''D. t. typus'' indicates that the subspecies was originally described in a genus other than ''Dispholidus''. Description The average adult boomslang is in total length. Some exceed . The eyes are exceptionally large, and the head has a characteristic egg-like shape. Coloration is highly variable. Males are light green ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrelaps
:''Common names: two-headed snakes.'' ''Micrelaps'' is a genus of rear-fanged venomous snakes in the family Atractaspididae. The genus is native to Africa and the Middle East. There are 4 species that are recognized as being valid. Description Species in the genus ''Micrelaps'' share the following characters: the maxilla is very short, with two teeth, followed, after an interspace, by a very large grooved fang situated below the eye. The mandibular teeth are longest anteriorly. The head is small, and is not distinct from the neck. The eye is minute, and the pupil is round or vertically subelliptic. The nostril is pierced in a single nasal scale. There is no loreal scale. There are no preocular scales, the prefrontal entering the eye. The body is cylindrical, and the tail is short. The dorsal scales are smooth, without pits, and are in 15 rows at midbody. The ventral scales are rounded. The subcaudal scales are in two rows. Species ''*) Not including the nominate subspecies'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrelaps
''Macrelaps'' (or Natal black snake) is a monotypic genus created for the rear-fanged (opisthoglyphous) venomous snake species, ''M. microlepidotus'', endemic to South Africa. No subspecies are currently recognized. Description (diagnosis) of genus Maxillary short, with four moderately large teeth, followed by a very large grooved fang situated below the eye. Anterior mandibular teeth enlarged, third to fifth longest. Head small, not distinct from neck. Eye minute, with round pupil. Nasal divided. No loreal. No preocular. Prefrontal entering the eye. Body cylindrical; tail short. Dorsal scales smooth, without pits, in 25 or 27 rows. Ventrals rounded; subcaudals single. Description of species ''Macrelaps microlepidotus'' is completely black dorsally and ventrally. It may attain in total length, with a tail long. Smooth dorsal scales arranged in 25 or 27 rows. Ventrals 163–166; anal plate entire; subcaudals 37–48, also entire. Portion of rostral visible from above nearly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homoroselaps
''Homoroselaps'' is a genus of venomous snakes of the family Atractaspididae.. Species * '' Homoroselaps dorsalis'' (Smith, 1849) * '' Homoroselaps lacteus'' (Linnaeus, 1758) References {{Taxonbar, from=Q5085060 Homoroselaps ''Homoroselaps'' is a genus of venomous snakes of the family Atractaspididae The Atractaspididae (atractaspidids) are a family of venomous snakes found in Africa and the Middle East, commonly called mole vipers, stiletto snakes, or burrowi ... Snake genera Taxonomy articles created by Polbot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoptophis
:''Common names: African bighead snake, wedge-snouted burrowing snake. ''Hypoptophis'' is a monotypic genus created for the rear-fanged (opisthoglyphous) venomous snake species, ''Hypoptophis wilsonii''. The species, which is endemic to Africa, is in the subfamily Aparallactinae of the family Atractaspididae. There are no subspecies that are recognized as being valid. Geographic range ''Hypoptophis wilsonii'' is found in Angola, southern Democratic Republic of the Congo (formerly Zaire), and Zambia. The type locality is "Inkongo, on the Sankuru River, in the Kasai Province of the Congo". Boulenger GA (1908). "Description of Three new Snakes from Africa". ''Annals and Magazine of Natural History, Eighth Series'' 2: 93-94. (''Hypoptophis wilsonii'', new species). Description (diagnosis) of genus The genus ''Hypoptophis'' exhibits the following characters. The maxilla is very short, with four teeth gradually increasing in size, followed, after an interspace, by two large grooved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilorhinophis
:''Common name: two-headed snakes.'' ''Chilorhinophis'' is a genus of venomous snakes endemic to Africa. Currently, three species are recognized. Species ''*) Not including the nominate subspecies.'' ) Type species. See also * Snakebite. References Further reading * Branch, Bill (2004). ''Field Guide to Snakes and other Reptiles of Southern Africa''. Third Revised Edition, Second impression. Sanibel Island Florida: Ralph Curtis Books. 399 pp. . (Genus ''Chilorhinophis'', p. 67). * Loveridge A (1958). "Revision of Five African Snake Genera". ''Bulletin of the Museum of Comparative Zoology at Harvard College'' 119: 1-198. (Genus ''Chilorhinophis'', pp. 168–169). * Werner F (1907). "''Ergebnisse der mit Subvention aus der Erbschaft Treitl unternommenen zoologischen Forschungreise Dr. Franz Werner's in den ägyptischen Sudan und nach Nord-Uganda. XII. Die Reptilien und Amphibien'' ". ''Sitzungsberichte der Mathematisch-Naturwissenschaftlichen Klasse der Kaiserlichen Akade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachyophis
''Brachyophis'' is a monotypic genus created for the rear-fanged venomous snake species, ''Brachyophis revoili'', commonly known as Revoil's short snake, which is endemic to Eastern Africa. Three subspecies are recognized as being valid. Description (diagnosis) of genus The maxillary is very short, with two or three small teeth, followed, after an interspace, by a large grooved fang. The mandibular teeth increase in length to the third. The head is small and is not distinct from the neck. The snout is depressed and sharp-edged. The eye is minute, with a round pupil. The nostril is pierced in a single nasal, which does not touch the rostral, the internasal forming a suture with the first upper labial. There is no loreal, and there are no temporals. A large azygous occipital shield is present. The body is remarkably short, and is cylindrical. The tail is extremely short. The dorsal scales are smooth, without apical pits, and are arranged in 15 rows at midbody. The ventrals are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aparallactus
:''Common name: centipede eaters.'' ''Aparallactus'' is a genus of rear-fanged venomous snakes found in Africa. Currently, 11 species are recognized. Description Maxillary short, with 6-9 small teeth followed by a large grooved fang situated below the eye. Anterior mandibular teeth longest. Head small, not distinct from neck. Eye small, with round pupil. Nasal entire or divided; no loreal. Body cylindrical; tail moderate or short. Dorsal scales smooth, without pits, arranged in 15 rows. Ventrals rounded; subcaudals single (not divided or paired). Boulenger GA. 1896. ''Catalogue of the Snakes in the British Museum (Natural History), Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ) ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (Genus ''Aparallactus'', pp. 255-256). Species ''*) Not including the nominate subspecies.'' ) Type species. See also * Snakebite A snakebite is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amblyodipsas
''Amblyodipsas'' is a genus of snakes found in Africa. Currently, 9 species are recognized.. These snakes are often known as purple-glossed snakes or glossy snakes. Although rear-fanged, all species are considered harmless, but their venom has not been well studied. They should not be confused with the glossy snakes of the genus ''Arizona'', which are found in North America. Description Maxillary very short, with five teeth gradually increasing in size and followed, after an interspace, by a large grooved fang situated below the eye. Mandibular teeth decreasing in size posteriorly. Head small, not distinct from neck; eye minute, with round pupil; nostril in a single very small nasal; no internasals; no loreal; no preocular; no anterior temporal. Body cylindrical. Dorsal scales smooth, without pits. Tail very short, obtuse. Subcaudals in two rows. Boulenger, G.A. (1896). ''Catalogue of the Snakes in the British Museum (Natural History), Volume III., Containing the Colubridæ (Opist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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