''Eristicophis'' 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 ...

, ''Eristicophis macmahonii'', which is

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 ...

to the desert region of

Balochistan Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...

near the borders of

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...

, and

Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...

. Common names for the species include McMahon's viper, Asian sand viper, leaf-nosed viper, and whiskered viper.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, 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.

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''macmahonii'' (or ''macmahoni'' ), is in honor of

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

diplomat

Arthur Henry McMahon Sir Arthur Henry McMahon (28 November 1862 – 29 December 1949) was a British Indian Army officer and diplomat who served as the High Commissioner in Egypt from 1915 to 1917. He was also an administrator in British India and served twice as ...

Description

''E. macmahonii'' is a relatively small species growing to a total length (including tail) of less than . Males are in total length, the females . The head is large, broad, flat, and wedge-shaped. It is also distinct from the neck. The snout is broad and short. The eyes are of a moderate size. The crown of the head is covered with small scales. The nostrils are a pair of small slits. It has a characteristic

rostral scale The rostral scale, or rostral, in snakes and other scaled reptiles is the median plate on the tip of the snout that borders the mouth opening. Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: ...

, that is wider than it is high, strongly concave, and bordered above and to the sides by four much enlarged

nasorostral scale In reptiles, the nasorostral is an enlarged and usually paired scale, just behind the rostralMallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. 359 pp. ...

s arranged in a butterfly shape. There are 14-16

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 ( ...

, which are separated from the

suboculars In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term ''oculus'' which ...

by 3-4 rows of small scales. There are 16-19

sublabials In reptiles, the sublabial scales, also called lower-labials or infralabials, are those scales that border the mouth opening along the lower jaw. They do not include the median scaleWright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publis ...

. The

circumorbital ring In scaled reptiles, the ocular scales are those forming the margin of the eye.Wright AH, Wright AA. 1957. ''Handbook of Snakes''. Comstock Publishing Associates (7th printing, 1985). 1105 pp. . The name originates from the term ''oculus'' which ...

consists of 16-25 scales. The body is dorsoventrally slightly depressed and appears moderately to markedly stout. The tail is short, and prehensile, tapering abruptly behind the vent. The skin feels soft and loose. The

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

are short and keeled, in 23-29 midbody rows that are arranged in a straight and regular pattern. The

ventral scales In snakes, the ventral scales or gastrosteges are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that conta ...

have lateral keels, numbering 140-144 in males and 142-148 in females. The

subcaudals 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 without keels: males have 33-36, females 29-31. The color pattern consists of a reddish to yellowish brown ground color, overlaid dorsolaterally with a regular series of 20-25 dark spots, bordered partly or entirely with white scales. Posteriorly, these spots become more distinct. The white border areas often extend over the back as crossbands. The head has a white stripe that runs from the back of the eye to the angle of the mouth. The top of the head may have scattered dark flecks. The labials and throat are white, as is the belly. The tip of the tail is yellow with distinct crossbands.

Geographic range

''E. macmahonii'' is found only in the desert region of

near the

border. The type-locality given is "Amirchah mir Cháh on map 30th March, 3300 feet, Zeh, 1st April, 2500 feet, Drana Koh, 2nd April, Robat I., May, 4300 feet" (3300 ft = 1000 m, 2500 ft. = 760 m, 4300 ft. = 1300 m). Listed as "W.

Baluchistan Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...

" in the catalogue of the Bombay Natural History Museum, Bombay India. M.A. Smith (1943:497) listed it as the "desert south of Helmand

iver Iver is a large civil parish in Buckinghamshire, England. In addition to the central clustered village, the parish includes the residential neighbourhoods of Iver Heath and Richings Park. Geography, transport and economy Part of the 43-square- ...

in Baluchistan". According to Mallow et al. (2003), this species is reported from Pakistan, Afghanistan, eastern and northwestern Baluchistan, southern Iran, and

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

in the Rajasthan Desert. It is limited to the Dast-i Margo Desert and nearby dune areas, from

Seistan Sistān ( fa, سیستان), known in ancient times as Sakastān ( fa, سَكاستان, "the land of the Saka"), is a historical and geographical region in present-day Eastern Iran ( Sistan and Baluchestan Province) and Southern Afghanistan (N ...

in the extreme east of Iran into Afghanistan south of the

Helmand River The Helmand River (also spelled Helmend, or Helmund, Hirmand; Pashto/Persian: ; Greek: ' (''Etýmandros''); Latin: ') is the longest river in Afghanistan and the primary watershed for the endorheic Sistan Basin. It emerges in the Sanglakh ...

. It also occurs in Baluchistan, between the

Chagai Hills The Chagai Hills is a range of granite hills in the Chagai District in Pakistan's Balochistan province. Location The Chagai Hills lie between 28' 46" to 29' 34" N and 63' 18" to 64' 50" in a desert area in the northernmost part of Chagai Dist ...

and

Siahan Range The Siahan Range is a mountain range in the central part of Balochistan Province of southwestern Pakistan. The Siahan Range is primarily made up of limestone and sandstone and was formed when the north western Indian Plate collided with the Eura ...

, east to

Nushki Nushki (Urdu , ) is a town and district in Balochistan, Pakistan. It lies in a plain south-west of Quetta, at an elevation of above sea level. From Nushki, the flat Balochistan desert stretches away northward and westward to the Helmand River. ...

Habitat

''Eristicophis macmahonii'' is associated with (shifting)

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s of fine, loose

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

. It is not found above an altitude of .

Behavior

''Eristicophis macmahonii'' employs rectilinear and serpentine motion to move around, but will sidewind when moving over loose sand or when alarmed. Occasionally, it climbs into

bushes A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

using its

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 ...

. This species is mainly

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, but may also be

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...

. It is also said to be bad-tempered, hissing very loudly and deeply. It will raise the front part of its body off the ground in a loop and strike aggressively. Leaf-nosed viper

''Eristicophis macmahoni'' can appear to sink down into the sand using a rocking or

peristaltic Peristalsis ( , ) is a radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, which ...

motion. Following this, it will usually shake and rotate its head along the longitudinal axis to cover its head, leaving only its snout and eyes free of sand. It is thought that the enlarged nasorostral scales keep sand from entering the nostrils.

Diet

''Eristicophis macmahonii''

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 ...

upon small

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, small

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, and sometimes

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

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' ...

are held in the mouth until dead, or nearly so.

Reproduction

The species ''E. macmahonii'' is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

, laying up to a dozen eggs. These hatch after 6–8 weeks, with each hatchling being about 6 inches (15 cm) in total length.Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. .

Venom

Relatively little data are available regarding the

venom 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 ...

of ''E. macmahonii'', but it is regarded as a potentially dangerous species by the United States Navy (1991) with venom similar to that of snakes of the genus ''

Echis ''Echis'' (common names: saw-scaled vipers, carpet vipersSpawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .) is a genus of vipers found in the dry regions of Africa, the Middle East ...

''.United States Navy (1991). ''Poisonous Snakes of the World''. New York: United States Government/Dover Publications Inc. 203 pp. . However, a protein in its venom called eristostatin has been reported to help in the fight against malignant

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

.https://www.economist.com/news/science-and-technology/21569015-snake-venom-being-used-cure-rather-kill-toxic-medicine Drug research: Toxic medicine

References

External links

* {{Taxonbar, from=Q1264749 Viperinae Reptiles of Iran Reptiles of Afghanistan Reptiles of Pakistan Monotypic snake genera Taxa named by Alfred William Alcock Taxa named by Frank Finn Reptiles described in 1897