Atheris Acuminata
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''Atheris'' is a genus of vipers known as bush vipers.Spawls S, Branch B (1995). ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . They are found only in tropical
subsaharan Africa Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the African ...
(excluding southern Africa) and many species have isolated and fragmented distributions due to their confinement to rain forests.Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Like all other vipers, they are venomous. In an example of convergent evolution, they show many similarities to the arboreal
pit vipers The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...
of Asia and South America. Seventeen species are currently recognized.


Description

They are relatively small in size, with adults ranging in total length (body + tail) from for '' A. katangensis'' to a maximum of for '' A. squamigera''. All species have a broad, triangular head that is distinct from the neck. The canthus is also distinct and the snout is broad. The crown is covered with small imbricate or smooth scales, none of which is enlarged. The eyes are relatively large with elliptical pupils. The eyes are separated from the
supralabials In reptiles, the supralabial scales, also called upper-labials, are those scales that border the mouth opening along the upper jaw. They do not include the median scaleWright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates ( ...
by 1–3 scale rows and from the nasal by 2–3 scales. The body is slender, tapering, and slightly compressed. The dorsal scales are overlapping, strongly keeled and have apical pits. Laterally these are smaller than the middorsals. Midbody there are 14–36 rows of dorsal scales. There are 133–175 rounded ventral scales. The
subcaudal scales In snakes, the subcaudal scales are the enlarged plates on the underside of the tail.Wright AH, Wright AA. 1957. Handbook of Snakes. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . These scales may be either single or divided (pair ...
are single and number 38–67. The tail is strongly prehensile and can support the body while suspended from a branch or a twig.Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . Members of this genus come in a wide variety of colors and patterns, often within a single species. '' A. ceratophora'' and '' A. squamigera'' are particularly variable.


Location

They inhabit rainforest regions and forests , mostly in remote areas far from human activity. They are found in tropical
subsaharan Africa Sub-Saharan Africa is, geographically, the area and regions of the continent of Africa that lies south of the Sahara. These include West Africa, East Africa, Central Africa, and Southern Africa. Geopolitically, in addition to the African ...
, excluding southern Africa. Some species have only isolated populations, surviving in small sections of ancient
rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
. They once had a much wider distribution but are now declining.


Conservation status

Some species are threatened by habitat destruction. A major cause of illness and mortality in both caged and wild bush viper snakes is Snake fungal disease(SFD).


Behavior

All species are strictly arboreal, although they can sometimes be found on or near the ground.


Diet

''Atheris'' species have been known to prey upon a variety of small
amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...
s,
lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
s, rodents, birds, and even other snakes. Some species or populations may specialize in eating frogs, but most have been described as opportunistic feeders. Prey is typically ambushed from a hanging position, held until it has succumbed to the venom, and then swallowed.


Reproduction

All ''Atheris'' species are ovoviviparous. Mating takes place in October and November, and the females give birth to live young in March and April.


Captivity

'' A. squamigera'' is reported to do very well in captivity, needing only arboreal access and having no particular temperature requirements. Captive specimens take
mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
and small birds. However, there have been reports of
cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, b ...
. Food may be refused during the African winter months of July and August.


Venom

Not much is known about their venom except that it is strongly hemotoxic, causing pain, swelling and blood clotting problems. Until recently, their venom has often been regarded as less toxic than that of many other species, perhaps because bites are uncommon, but this turned out not to be the case. There are now a number of reports of bites that have led to severe hemorrhaging.Bitten by a Sedge Viper!
a
VenomousReptiles.org
. Accessed 2 August 2007.
One case was fatal. ''Atheris''-specific antivenom does not exist and antivenom meant for bites from other species seem to have little effect, although '' Echis'' antivenom has been reported to have been of some help in a case of '' A. squamigera'' envenomation. Symptomatic replacement therapy is applied due to the absence of an Atheris specific antivenom.Wang, He, et al. (2018). "Comparative Profiling of Three ''Atheris'' Snake Venoms: ''A. squamigera, A. nitschei and A. chlorechis'' ". ''The Protein Journal'' 37 (4): 353–360. doi:10.1007/s10930-018-9781-y.


Species

''*) Not including the nominate subspecies''
T'') Type species


Taxonomy

Other species may be encountered in literature, such as: Until relatively recently, the following species, all of which are terrestrial, were also included in the genus ''Atheris'': *''
Montatheris hindii ''Montatheris'' is a monotypic genus created for the viper species, ''Montatheris hindii'', which also known by the common names Kenya mountain viper,Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World ...
'' (
Boulenger Boulenger is a surname. Notable people with the surname include: * Benjamin Boulenger (born 1990), French footballer * Edward George Boulenger (1888–1946), British zoologist, director of aquarium at London Zoo * George Albert Boulenger (1858–1 ...
, 1910)
– montane viper *'' Proatheris superciliaris'' ( W. Peters, 1855) – lowland viper Together with ''Atheris'', these three
genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
are sometimes referred to as the tribe Atherini.


References


Further reading

* * Boulenger GA (1896). ''Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the ...Viperidæ''. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers.) xiv + 727 pp. + Plates I.- XXV. (Genus ''Atheris'', p. 508.) * * * * * * * *


External links

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