Echis

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Echis
Saw-scaled Viper (Echis carinatus) Photographed By Shantanu Kuveskar.jpg
Echis carinatus in Mangaon (Maharashtra, India)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Subfamily: Viperinae
Genus: Echis
Merrem, 1820
Synonyms [1]

Echis (common names: saw-scaled vipers, carpet vipers [2] ) is a genus of vipers found in the dry regions of Africa, the Middle East, India, Sri Lanka and Pakistan. They have a characteristic threat display, rubbing sections of their body together to produce a "sizzling" warning sound. [3] The name Echis is the Latin transliteration of the Greek word for "viper" (ἔχις). Like all vipers, they are venomous. Their common name is "saw-scaled vipers" and they include some of the species responsible for causing the most snakebite cases and deaths in the world. [4] [5] Twelve species are currently recognized. [6]

Contents

Description

Closeup: scales with serrated keels Echis carinatus gab.png
Closeup: scales with serrated keels

Saw-scaled vipers are relatively small snakes, the largest species ( E. leucogaster, E. pyramidum ) usually below 90 cm (35 in) long, and the smallest ( E. hughesi, E. jogeri ) being around 30 cm (12 in).

The head is relatively small and is short, wide, pear-shaped and distinct from the neck. The snout is short and rounded, while the eyes are relatively large and the body is moderately slender and cylindrical. The dorsal scales are mostly keeled. However, the scales on the lower flanks stick out at a distinct 45° angle and have a central ridge, or keel, that is serrated (hence the common name). The tail is short and the subcaudals are single. [3]

A saw-scaled viper of the genus Echis may be responsible for biblical claims of a fiery flying serpent. [7]

Geographic range

Species of this genus are found in Pakistan, India (in rocky regions of Maharashtra, Rajasthan, Uttar Pradesh, and Punjab) and Sri Lanka, parts of the Middle East, and Africa north of the equator. [1]

Behaviour

All members of this genus have a distinctive threat display, which involves forming a series of parallel, C-shaped coils and rubbing their scales together to produce a sizzling sound, rather like water on a hot plate. [2] [3] The proper term for this is stridulation. [8] As they become more agitated, this stridulating behavior becomes faster and louder. This display is thought to have evolved as a means of limiting water loss, such as might occur when hissing. [3] However, some authors describe this display as being accompanied by loud hissing. [8]

These snakes can be fierce and are quick to strike. They will strike from the position described above. When doing so, they may overbalance and end up moving towards their aggressor (an unusual behavior for snakes). [2]

Saw-scaled vipers are highly defensive compared to many of their cousins and they are very easy to provoke, so they might strike quickly.[ citation needed ]

Diet

Little is known about the diets of some Echis species. For others, their diets are reported to be extremely varied, and may include items such as locusts, beetles, worms, slugs, spiders, scorpions, centipedes, solifugids, frogs, toads, reptiles (including other snakes), small mammals, and birds. [2] [3]

Reproduction

Most Echis species, such as those found in Africa, are oviparous, while others, such as those in India, are viviparous. [2] [3]

Venom

The snake venom of Echis species consists mostly of four types of toxins: neurotoxins, cardiotoxins, hemotoxins, and cytotoxins. The genus is recognized as medically significant in many tropical rural areas. They are widespread and live in areas lacking modern medical facilities. Most victims are bitten after dark when these snakes are active. [3]

Most of these species have venom that contains factors that can cause a consumption coagulopathy and defibrination, which may persist for days to weeks. This may result in bleeding anywhere in the body, including the possibility of an intracranial hemorrhage. The latter classically occurs a few days following the bite. [9]

Venom toxicity varies among the different species, geographic locations, individual specimens, sexes, over the seasons, different milkings, and, of course, the method of injection (subcutaneous, intramuscular, or intravenous). Consequently, the LD50 values for Echis venoms differ significantly. In mice, the intravenous LD50 ranges from 2.3 mg/kg (U.S. Navy, 1991) to 24.1 mg/kg (Christensen, 1955) to 0.44–0.48 mg/kg (Cloudsley-Thompson, 1988). In humans, the lethal dose is estimated to be up to 5 mg in some subspecies (Daniels, J. C. 2002). [10] Venom from females was more than twice as toxic on average as venom from males. [3]

The amount of venom produced also varies. Reported yields include 20–35 mg of dried venom from specimens 41–56 cm in length, [11] 6–48 mg (16 mg average) from Iranian specimens [12] and 13–35 mg of dried venom from animals from various other localities. [13] Yield varies seasonally, as well as between the sexes: the most venom is produced during the summer months and males produce more than females. [3]

Species

ImageSpecies [1] Taxon author [1] Subsp.* [6] Common nameGeographic range [1]
E. borkini Cherlin, 19900Southwestern Arabian Peninsula (western Yemen, southern Saudi Arabia)
Echis carinatus sal (edit).jpg E. carinatus T(Schneider, 1801)4Saw-scaled viperSoutheastern Arabian Peninsula (Oman, Masirah and eastern UAE), southwestern Iran, Iraq, Afghanistan, Uzbekistan, Turkmenistan, Tajikistan, Pakistan (including Urak near Quetta and Astola Island off the Makran Coast), India, Sri Lanka
Ap`h mgvvn-2.jpg E. coloratus Günther, 18780Painted saw-scaled viperSoutheastern Egypt east of the Nile and as far south as the 24th parallel, Sinai, Israel, Jordan, and the Arabian Peninsula in Saudi Arabia, Yemen and Oman
E. hughesi Cherlin, 19900Hughes' saw-scaled viper Somalia: northern Migiurtinia, near Meledin
E. jogeri Cherlin, 19900Joger's saw-scaled viperWestern and central Mali, Senegal
E. khosatzkii Cherlin, 19900Khosatzki's saw-scaled viperEastern Yemen and Oman
E. leucogaster Roman, 19720White-bellied carpet viperWest and northwest Africa: extreme southern Morocco, Western Sahara, Algeria (Ahaggar), the southern region of Mauritania, Senegal, northern Guinea, central Mali, Burkina Faso, western Niger and northern Nigeria
E. megalocephalus Cherlin, 19900Cherlin's saw-scaled viper Red Sea island between Yemen and Eritrea (Dahlak Archipelago)
E. ocellatus Stemmler, 19700African saw-scaled viperNorthwest Africa: Mauritania, Senegal, Mali, Guinea, Ivory Coast, Burkina Faso, Ghana, Togo, Benin, southern Niger, Nigeria
E. omanensis Babocsay, 20040Oman saw-scaled viperUnited Arab Emirates, Eastern Oman
Echis pyramidum.jpg E. pyramidum (Geoffroy Saint-Hilaire, 1827)2Egyptian saw-scaled viperNortheastern Africa: northern Egypt and central Sudan, Eritrea, Ethiopia, Somalia and northern Kenya; disjunct populations in the northern regions of Libya, Tunisia and Algeria
E. romani Trape, 20180Roman's carpet viperSouthwestern Chad, southern Niger, Nigeria, northern Cameroon, northwestern Central African Republic

*) Not including the nominate subspecies
T) Type species

Taxonomy

The taxonomy of the group was long confused, with a plethora of species of uncertain status. Several recent studies have clarified the diversity within the genus. This included the descriptions of E. omanensis [14] and E. romani. [15]

A mitochondrial DNA phylogeny for the genus [16] demonstrated the distinctiveness of E. borkini, E. jogeri and E. khosatzkii, but showed E. multisquamatus to be a synonym of E. carinatus.

Related Research Articles

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Cerastes cerastes, commonly known as the Saharan horned viper or the desert horned viper, is a venomous species of viper native to the deserts of Northern Africa and parts of the Arabian Peninsula and Levant. It is often easily recognized by the presence of a pair of supraocular "horns", although hornless individuals do occur. Three subspecies have been described.

<i>Echis carinatus</i> Species of snake

Echis carinatus, known as the saw-scaled viper, Indian saw-scaled viper, little Indian viper, and by other common names, is a viper species found in parts of the Middle East and Central Asia, and especially the Indian subcontinent. It is the smallest member of the "big four" Indian snakes that are responsible for causing the most snakebite cases and deaths, due to various factors including their frequent occurrence in highly populated regions, and their inconspicuous nature. Like all vipers, the species is venomous. Two subspecies are currently recognized, including the nominate subspecies described here.

<i>Echis coloratus</i> Species of reptile

Echis coloratus, known as the painted saw-scaled viper, painted carpet viper, Burton's carpet viper, and by other common names, is a highly venomous viper species endemic to the Middle East and Egypt. No subspecies are currently recognized.

<span class="mw-page-title-main">Gaboon viper</span> Species of snake

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<span class="mw-page-title-main">Russell's viper</span> Species of venomous snake

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<i>Atractaspis</i> Genus of snakes

Atractaspis is a genus of venomous snakes in the family Atractaspidae, also known as the stiletto snakes. The genus is endemic to Africa and the Middle East. The genus contains 15 species that are recognized by ITIS. Others recognize as many as 21 species. 23 are listed here.

<i>Echis megalocephalus</i> Species of snake

Echis megalocephalus, also known commonly as the big-headed carpet viper and Cherlin's saw-scaled viper, is a species of venomous snake in the family Viperidae. The species is endemic to one island in the Red Sea off the coast of Eritrea. There are no subspecies that are recognized as being valid.

<i>Atheris squamigera</i> Species of snake

Atheris squamigera is a venomous viper species endemic to west and central Africa. No subspecies are currently recognized.

<i>Atheris</i> Genus of venomous vipers of tropical Africa

Atheris is a genus of vipers known as bush vipers. They are found only in tropical subsaharan Africa and many species have isolated and fragmented distributions due to their confinement to rain forests. Like all other vipers, they are venomous. In an example of convergent evolution, they show many similarities to the arboreal pit vipers of Asia and South America. Seventeen species are currently recognized.

<i>Causus</i> Genus of snakes

Causus is a genus of vipers found only in sub-Saharan Africa. It is a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus, and because they have round pupils. However, this is contradicted by recent molecular studies. Seven species are currently recognized. They are commonly known as night adders. Like all other vipers, they are venomous.

Proatheris is a monotypic genus created for the viper species, Proatheris superciliaris. This is a small terrestrial species endemic to East Africa. Like all other vipers, it is venomous. No subspecies are currently recognized.

<i>Vipera</i> Genus of snakes

Vipera is a genus of snakes in the subfamily Viperinae of the family Viperidae. The genus has a very wide range, being found from North Africa to just within the Arctic Circle, and from Great Britain to Pacific Asia. The Latin name vīpera is possibly derived from the Latin words vivus and pario, meaning "alive" and "bear" or "bring forth"; likely a reference to the fact that most vipers bear live young. 21 species are recognized as being valid. Like all other vipers, the members of this genus are venomous.

<i>Vipera aspis</i> Species of snake

Vipera aspis is a viper species found in southwestern Europe. Its common names include asp, asp viper, European asp, and aspic viper, among others. Like all other vipers, it is venomous. Bites from this species can be more severe than from the European adder, V. berus; not only can they be very painful, but approximately 4% of all untreated bites are fatal. The specific epithet, aspis, is a Greek word that means "viper." Five subspecies are currently recognized, including the nominate subspecies described here.

<i>Echis hughesi</i> Species of snake

Echis hughesi, also known commonly as Hughes' carpet viper, the Somali carpet viper, and Hughes' saw-scaled viper, is a species of venomous snake in the subfamily Viperinae of the family Viperidae. The species is endemic to Somalia. There are no subspecies that are recognized as being valid.

Echis jogeri, also known commonly as Joger's carpet viper, the Mali carpet viper, and Joger's saw-scaled viper, is a species of venomous snake in the family Viperidae. The species is endemic to Mali. There are no subspecies which are recognized as being valid.

Echis leucogaster, also known as the white-bellied carpet viper or the Roman's saw-scaled viper, is a viper species endemic to West and Northwest Africa. Its scientific name derives from its white (leuco-), unmarked belly (gaster). like all other vipers, it is venomous. No subspecies are currently recognized.

Echis ocellatus, known by the common names West African carpet viper and ocellated carpet viper, is a highly venomous species of viper endemic to West Africa. No subspecies are currently recognized.

<i>Echis pyramidum</i> Venomous snake, a carpet viper

Echis pyramidum, known as the Northeast African carpet viper, Egyptian saw-scaled viper, and by other common names, is a species of viper endemic to Northeast Africa and the Arabian Peninsula. Like all other vipers, it is venomous. Three subspecies are currently recognized, including the nominate subspecies described here.

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<span class="mw-page-title-main">Persian horned viper</span> Species of snake

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References

  1. 1 2 3 4 5 McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1. Washington, District of Columbia: Herpetologists' League. 511 pp. ISBN   1-893777-00-6 (series). ISBN   1-893777-01-4 (volume).
  2. 1 2 3 4 5 Spawls S, Branch B. 1995. The Dangerous Snakes of Africa. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. ISBN   0-88359-029-8.
  3. 1 2 3 4 5 6 7 8 9 Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Malabar, Florida: Krieger Publishing Company. 359 pp. ISBN   0-89464-877-2.
  4. ↑ Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates. 870 pp. 1500 plates. ISBN   0-8014-4141-2.
  5. ↑ Oldfield, Paige (22 December 2021). "One of the world's deadliest snakes found on industrial estate in Salford". Manchester Evening News. Retrieved 24 December 2021.
  6. 1 2 "Echis". Integrated Taxonomic Information System . Retrieved 31 July 2006.
  7. ↑ Millett, Ronald P.; Pratt, John P. (5 November 2008). "What Fiery Flying Serpent Symbolized Christ?". Meridian Magazine. Church of the Latter-Day Saints. Archived from the original on 10 June 2007.
  8. 1 2 Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN   0-8069-6460-X.
  9. ↑ Campbell CH. 1995. "Snake bite and snake venoms: their effects on the nervous system". In: de Wolff FA, editor. Handbook of clinical neurology, vol 21 (65). Intoxications of the nervous system, part II. Amsterdam: Elsevier Science Publications.
  10. ↑ Daniel, J. C. (2002). The book of Indian reptiles and amphibians. Mumbai: Oxford University Press. p. 153. ISBN   0-19-566099-4.
  11. ↑ Minton 1974. U.S. Navy. 1991.
  12. ↑ Latifi 1991.
  13. ↑ Boquet 1967.
  14. ↑ Babocsay, Gergely (2004). "A new species of saw‐scaled viper of the Echis coloratus complex (Ophidia: Viperidae) from Oman, Eastern Arabia". Systematics and Biodiversity. 1 (4): 503–514. doi:10.1017/S1477200003001294. S2CID   86159757.
  15. ↑ Trape, Jean-François (2018). "Partition d'Echis ocellatus Stemmler, 1970 (Squamata, Viperidae), avec la description d'une espèce nouvelle". Bulletin de la Société Herpétologique de France. 167: 13–34.
  16. ↑ Pook, Catharine E.; Joger, Ulrich; Stümpel, Nikolaus; Wüster, Wolfgang (1 December 2009). "When continents collide: Phylogeny, historical biogeography and systematics of the medically important viper genus Echis (Squamata: Serpentes: Viperidae)". Molecular Phylogenetics and Evolution. 53 (3): 792–807. doi:10.1016/j.ympev.2009.08.002. PMID   19666129.

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