''Proatheris'' (commonly referred to as the lowland viper and swamp viper among

other names Other often refers to: * Other (philosophy), a concept in psychology and philosophy Other or The Other may also refer to: Film and television * ''The Other'' (1913 film), a German silent film directed by Max Mack * ''The Other'' (1930 film), ...

) is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

created for the

viper The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs tha ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, ''Proatheris superciliaris''. This is a small

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

species

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

East Africa East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical ...

. Like all other vipers, it is

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

. No

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

are currently recognized.

Description

''Proatheris superciliaris'' is a small species that averages 40 to 50 cm (about 16 to 20 inches) in total length (body + tail), with a maximum total length of . The females are slightly larger than the males. The head has a somewhat elongated appearance, the top of which is covered with small scales except for a pair of large

supraocular scales In scaled reptiles, supraocular scales are (enlarged) scales on the crown immediately above the eye.Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. ...

, which are almost twice as long as they are wide.Mallow D, Ludwig D, Nilson G. 2003. ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. .

Common names

Common names for the ''Proatheris'' include the lowland viper, swamp viper,Spawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. . lowland swamp viper, eyebrow viper, swamp adder, Peter's viper, flood-plain viper, Mozambique viper, African lowland viper,Brown JH. 1973. ''Toxicology and Pharmacology of Venoms from Poisonous Snakes''. Springfield, Illinois: Charles C. Thomas. 184 pp. LCCCN 73-229. . and the domino viper.U.S. Navy. 1991. ''Poisonous Snakes of the World''. US Govt. New York: Dover Publications Inc. 203 pp. .

Geographic range

It is found in East Africa. The southern part of its range begins near Beira, in central

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...

, extends up north over the Mozambique Plain to Quissanga, and through

Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeast ...

and as far north as the floodplains of southern

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands and ...

at the northern end of

Lake Malawi Lake Malawi, also known as Lake Nyasa in Tanzania and Lago Niassa in Mozambique, is an African Great Lake and the southernmost lake in the East African Rift system, located between Malawi, Mozambique and Tanzania. It is the fifth largest fre ...

. The type locality given is ''"Terra Querimba"'' (= Quissanga mainland opposite Ilha Quirimba, Mozambique). Its range is apparently centered on the lower section of the

Zambezi River The Zambezi River (also spelled Zambeze and Zambesi) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers , slightly less than hal ...

and spreads out into the coastal plain of central Mozambique and the Shire Valley to

Lake Chilwa Lake Chilwa is the second-largest lake in Malawi after Lake Malawi. It is in eastern Zomba District, near the border with Mozambique. Approximately 60 km long and 40 km wide, the lake is surrounded by extensive wetlands. There is an islan ...

and Malawi. However, other specimens have been found far from this region, such as in Cape Delgado Province, in north-eastern Mozambique, and Mwaya in south-western Tanzania.

Habitat

It is almost always found in low-lying

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

es,

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s and land frequently used for grazing cattle. The soil is never too dry, since this would make it difficult for the

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s that they feed on to dig their burrows. These snakes are entirely terrestrial and are usually found in or around these rodent

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

Behaviour

One of the distinguishing characteristics of the ''

Atheris ''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 (excluding southern Afri ...

'' group (to which ''Proatheris'' is closely related), is that they have

prehensile tail A prehensile tail is the tail of an animal that has adapted to grasp or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees. If the ta ...

s. With ''Proatheris'', the young and subadults have this capability, but it is diminished in the adults.

Feeding

Preys Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

mainly on small

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s and

toad Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. A distinction between frogs and toads is not made in scientif ...

s. Occasionally, it also feeds on small rodents.

Reproduction

This species is

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the m ...

, with typically 3-16 neonates.

Venom

The first known case of a survivor of

snakebite A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occu ...

by this species was reported by Els (1988), involving a juvenile and 24-year-old victim penetrated by a single fang. The results were painful, but there were none of the strongly

hemotoxic Hemotoxins, haemotoxins or hematotoxins are toxins that destroy red blood cells, disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term ''hemotoxin'' is to some degree a misnomer since toxins that damage ...

symptoms that had been associated with ''

'' venom up to that point. In a second case in 1996, a victim experienced severe

hemolysis Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo o ...

and complete

platelet Platelets, also called thrombocytes (from Greek θρόμβος, "clot" and κύτος, "cell"), are a component of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping, thereby ini ...

destruction after which his liver and kidneys began to fail. When it was feared that the patient might die from hemolytic-uremic syndrome,

plasmapheresis Plasmapheresis (from the Greek πλάσμα, ''plasma'', something molded, and ἀφαίρεσις ''aphairesis'', taking away) is the removal, treatment, and return or exchange of blood plasma or components thereof from and to the blood circulati ...

was performed. Luckily, the patient survived, but it is now obvious that ''P. superciliaris'' venom is very

Taxonomy

This species was previously placed in the genus ''

'' based on skull characteristics and because of its partially prehensile tail.

Etymology

The generic name, ''Proatheris'', is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

for "before-''atheris''".

References

External links

{{Taxonbar, from=Q2007587 Viperinae Monotypic snake genera Reptiles described in 1854