Field's horned viperMallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company, Malabar, Florida. 359 pp. . (''Pseudocerastes fieldi'') is a

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 ...

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 deserts of the

Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...

. 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 ...

. It was previously considered a subspecies of the

Persian horned viper The Persian horned viper (''Pseudocerastes persicus''), known as the Persian horned viper, false horned viper,Mallow D, Ludwig D, Nilson G. 2003. ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publi ...

. The main differences between this species and the Persian horned viper are in scalation and venom composition.

Taxonomy

Many sources elevate ''P. fieldi'' to species level. The first phylogenetic study of the genus ''

Pseudocerastes ''Pseudocerastes'' is a genus of vipers endemic to the Middle East and Asia. It was originally created as a monotypic genus in 1896 by Boulenger for the species ''Pseudocerastes persicus'', but three species are now recognised: the spider-tailed ...

'', published by Fathinia et al. in 2014, shows that ''P. fieldi'' has equal genetic distance from both ''P. persicus'' and another species of the same genus, '' P. urarachnoides''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''fieldi'' is in honor of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

anthropologist An anthropologist is a person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and ...

Henry Field, who collected the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

. The

Field Museum of Natural History The Field Museum of Natural History (FMNH), also known as The Field Museum, is a natural history museum in Chicago, Illinois, and is one of the largest such museums in the world. The museum is popular for the size and quality of its educational ...

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

and its scientific publication, ''Fieldiana'', in which K.P. Schmidt's original description of this viper appeared, are named for Henry Field's grandfather,

Marshall Field Marshall Field (August 18, 1834January 16, 1906) was an American entrepreneur and the founder of Marshall Field and Company, the Chicago-based department stores. His business was renowned for its then-exceptional level of quality and customer ...

.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Pseudocerastes fieldi'', p. 89).

Description

Outwardly, Field's horned viper differs from the

(''Pseudocerastes persicus'') in certain (lower) scale counts:Spawls S, Branch B (1995). ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .
Additional differences from the Persian horned viper include much shorter (relatively to the overall body length) tail as well as the fact that while in ''P. persicus'' all dorsal and lateral scales are strongly keeled, ''P. fieldi'' has several rows of almost smooth lateral scales.

Geographic distribution

According to

McDiarmid McDiarmid, also MacDiarmid, is an Irish surname originating from a high king of Ireland circa 657 AD, popular in Scotland. People Notable people with this surname include: McDiarmid * Archie McDiarmid (1881–1957), Scottish-born Canadian track ...

et al. (1999) ''P. fieldi'' is found in the

Sinai Peninsula The Sinai Peninsula, or simply Sinai (now usually ) (, , cop, Ⲥⲓⲛⲁ), is a peninsula in Egypt, and the only part of the country located in Asia. It is between the Mediterranean Sea to the north and the Red Sea to the south, and is a l ...

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

Jordan Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...

, northern

Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the A ...

, northwestern

Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...

, and possibly in southern

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

. The type locality given in the original description is "Bair Wells, Transjordania" ordan According to Mallow et al. (2003) it is found in the Sinai Peninsula, southern Israel, Jordan, extreme northern Saudi Arabia, and southwestern Iraq.

Venom

There is a more pronounced difference between the two subspecies with regard to their

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 ...

. While

venom exhibits strong

hemorrhagic Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vagi ...

activity typical of most

vipers 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 ...

, the venom of ''P. fieldi'' is unusual in that contains several fractions that show marked

neurotoxic Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specificall ...

activity. No

antivenin Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if th ...

is available for

bites Biting is a common zoological behavior involving the active, rapid closing of the jaw around an object. This behavior is found in toothed animals such as mammals, reptiles, amphibians and fish, but can also exist in arthropods. Myocytic contrac ...

from either subspecies. It is reported that a polyvalent antiserum does offer some protection from the hemotoxins, but none against the neurotoxic effects of ''P. fieldi'' venom.

References

External links