Viperinae

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Viperinae
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Reptilia Order: Squamata Suborder: Serpentes Family: Viperidae Subfamily: Viperinae Oppel, 1811
Synonyms
Viperini - Oppel, 1811 Viperes - Cuvier, 1817 Viperides - Latreille, 1825 Viperina - Gray, 1825 Viperiodea - Fitzinger, 1826 Viperiodei - Eichwald, 1831 Viperinae - Cantor, 1847 Viperiformes - Günther, 1864 Viperida - Strauch, 1869

Common names: pitless vipers, true vipers, Old World vipers.  
 
The Viperinae, or viperines, are a subfamily of venomous vipers found in Europe, Asia and Africa. They are distinguished by their lack of the heat-sensing pit organs that characterize their sister group, the Crotalinae. Currently, 12 genera and 66 species are recognized. Most are tropical and subtropical, although one species, Vipera berus, even occurs within the Arctic Circle.

Description

Members of this subfamily range in size from Bitis schneideri, that grows to a maximum of 28 cm, to Bitis gabonica that reaches a maximum length of over 2 m. Most species are terrestrial, but a few, such as Atheris, are completely arboreal.

Although the heat-sensing pits that characterize the Crotalinae are clearly lacking in the viperines, a supernasal sac with sensory function has been described in a number of species. This sac is an invagination of the skin between the supranasal and nasal scales and is connected to the ophthalmic branch of the trigeminal nerve. The nerve endings here resemble those in the labial pits of boas. The supernasal sac is present in Daboia, Pseudocerastes and Causus, but is especially well developed in Bitis. Experiments have shown that strikes are not only guided by visual and chemical cues, but also by heat, with warmer targets being struck more frequently than colder ones.

Geographic range

Found in Europe, Asia and Africa. However, they do not occur in Madagascar.

Reproduction

Generally, members of this subfamily are viviparous (ovoviviparous), although a few, such as Pseudocerastes, lay eggs.

Genera

Genus	Authority	Species	Subsp.*	Common name	Geographic range
Adenorhinos	Loveridge, 1930	1	0	Uzungwe viper	Central Tanzania: Udzungwe and Ukinga Mountains.
Atheris	Cope, 1862	8	1	Bush vipers	Tropical subsaharan Africa, excluding southern Africa.
Bitis	Gray, 1842	14	2	Puff adders	Africa and the southern Arabian Peninsula.
Cerastes	Laurenti, 1768	3	0	Desert vipers	North Africa eastward through Arabia and Iran.
Daboia	Gray, 1842	1	1	Russell's viper	Pakistan, India, Sri Lanka, Bangladesh, Nepal, Myanmar, Thailand, Cambodia, China (Kwangsi and Kwantung), Taiwan and Indonesia (Endeh, Flores, east Java, Komodo, Lomblen Islands).
Echis	Merrem, 1820	8	6	Saw-scaled vipers	India and Sri Lanka, parts of the Middle East and Africa north of the equator.
Eristicophis	Alcock and Finn, 1897	1	0	McMahon's viper	The desert region of Balochistan near the Iran-Afghanistan-Pakistan border.
Macrovipera	Reuss, 1927	4	4	Large Palearctic vipers	Semideserts and steppes of northern Africa, the Near and Middle East, and the Milos Archipelago in the Aegean Sea.
Montatheris	Boulenger, 1910	1	0	Montane viper	Kenya: moorlands of the Aberdare range and Mount Kenya above 3000 m.
Proatheris	Peters, 1854	1	0	Lowland viper	Floodplains from southern Tanzania (northern end of Lake Malawi) through Malawi to near Beira, central Mozambique.
Pseudocerastes	Boulenger, 1896	1	1	Horned vipers	From the Sinai of Egypt eastward to Pakistan.
ViperaT	Laurenti, 1768	23	12	Palearctic vipers	Great Britain and nearly all of continental Europe across the Arctic Circle and on some islands in the Mediterranean (Elba, Montecristo, Sicily) and Aegean Sea eastward across northern Asia to Sakhalin Island and North Korea. Also found in northern Africa in Morocco, Algeria and Tunisia.

*) Not including the nominate subspecies (typical form).
^T) Type genus.

Taxonomy

Until relatively recently, two other genera were also included in the Viperinae. However, they were eventually considered so distinctive within the Viperidae, that separate subfamilies were created for them:

• Genus Azemiops - moved to subfamily Azemiopinae by Liem, Marx & Rabb (1971).
• Genus Causus - recognition of subfamily Causinae (Cope, 1860) was proposed by Groombridge (1987) and further supported by Cadle (1992).

Nevertheless, these groups, together with the genera currently recognized as belonging to the Viperinae, are still often referred to collectively as the true vipers.

One tribe is currently recognized, Atherini, created by Broadley in 1996 to describe the genera Atheris, Adenorhinos, Montatheris and Proatheris. The type genus for this tribe is Atheris.