Bitis
Encyclopedia
Common names: puff adders, African adders, African vipers.

Bitis is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of venomous
Venomous snake
"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 viper
Viperidae
The Viperidae are a family of venomous snakes found all over the world, except in Antarctica, Australia, Ireland, Madagascar, Hawaii, various other isolated islands, and above the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four...

s found in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 and the southern Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...

. It includes the largest and the smallest vipers in the world. Members are known for their characteristic threat displays that involves inflating and deflating their bodies while hissing and puffing loudly. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 for this genus is B. arietans
Bitis arietans
Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...

, which is also the most widely distributed viper in Africa. Currently, 14 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 are recognized.

Description

Size variation within this genus is extreme, ranging from the very small B. schneideri
Bitis schneideri
Bitis schneideri is a venomous viper species found in a small coastal region that straddles the border between Namibia and South Africa. This is the smallest species in the genus Bitis and possibly the world's smallest viperid...

, which grows to a maximum of 28 cm and is perhaps the world's smallest viperid
Viperidae
The Viperidae are a family of venomous snakes found all over the world, except in Antarctica, Australia, Ireland, Madagascar, Hawaii, various other isolated islands, and above the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four...

, to the very large B. gabonica
Bitis gabonica
Bitis gabonica is a venomous viper species found in the rainforests and savannas of Sub-Saharan Africa. This is not only the largest member of the genus Bitis, but also the world's heaviest viperid and it has the longest fangs ,and the highest venom yield of any venomous snake...

, which can attain a length of over 2 m and is the heaviest viper in the world.

All have a wide, triangular head with a rounded snout, distinct from the neck, and covered in small, keeled, imbricate scales. The canthus
Canthus (snake)
In snakes and amphibians, the canthus, canthal ridge or canthus rostralis, is the angle between the flat crown of the head and the side of the head between the eye and the snout. More specifically, between the supraocular scale and the rostral scale. It is defined as a sharp ridge in many viperids,...

 is also distinct. A number of species have enlarged rostral or supraorbital
Supraocular scales
In scaled reptiles, supraocular scales are scales on the crown immediately above the eye. The size and shape of these scales are among the many characteristics used to differentiate species from each another....

 scales that look like horns. The eyes are relatively small. They have large nostrils that are directed outwards and/or upwards. 0-6 rows of small scales separate the rostral and nasal scales. All species have a well-developed supranasal sac. The front of the maxillary bones are very short, supporting only one pair of recurved fangs.

These snakes are moderately to extremely stout. The body is covered with keeled
Keeled scales
Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch...

 scales that are imbricate with apical pits. At midbody, the dorsal scales
Dorsal scales
In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales.When counting dorsal scales, numbers are often given for three points along the body, for example 19:21:17...

 number 21-46. Laterally, the dorsal scales may be slightly oblique. The ventral scales
Ventral scales
In snakes, the ventral scales 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 contacts the paraventral row of dorsal scales on either side...

, which number 112-153, are large, rounded and sometimes have slight lateral keels. The tail is short. Anal scale
Anal scale
In snakes, the anal scale is the scale just in front of and covering the cloacal opening. This scale can be either single or paired . When paired, the division is oblique. It is preceded by the ventral scales and followed by the subcaudal scales....

 single. The paired subcaudal scales
Subcaudal scales
In snakes, the subcaudal scales are the enlarged plates on the underside of the tail. These scales may be either single or divided and are preceded by the anal scale....

 number 16-37 and are sometimes keeled laterally.

Behavior

Bitis species are known for their behavior of inflating and deflating their bodies in loud hissing or puffing threat displays. They are terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 ambush predators and appear sluggish, but can strike with amazing speed. In contrast to the pitvipers of the subfamily Crotalinae
Crotalinae
The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

, Bitis species appear to lack heat-sensitive organs and showed no differences in their behavior in laboratory tests towards warm and cool objects that mimicked prey.

Venom

All members of this genus are dangerous — some extremely so. At least six different polyvalent antivenoms are available. Five are produced by Aventis Pasteur (France), Pasteur Merieux (France) and SAIMR (South Africa). All of these specifically protect against B. arietans
Bitis arietans
Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...

 and four also cover B. gabonica
Bitis gabonica
Bitis gabonica is a venomous viper species found in the rainforests and savannas of Sub-Saharan Africa. This is not only the largest member of the genus Bitis, but also the world's heaviest viperid and it has the longest fangs ,and the highest venom yield of any venomous snake...

. At least one protects specifically against bites from B. nasicornis
Bitis nasicornis
Bitis nasicornis is a venomous viper species found in the forests of West and Central Africa. A big viper known for its striking color pattern and prominent horns on its nose. No subspecies are recognized.-Description:...

: India Antiserum Africa Polyvalent. In the past, such antivenoms have been used to treat bites from other Bitis species, but with mixed results.

Species

Species Taxon author Subsp.* Common name Geographic range
B. arietans
Bitis arietans
Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...

T
(Merrem
Blasius Merrem
Blasius Merrem was a German naturalist.Merrem was born at Bremen, and studied at the university of Göttingen under Johann Friedrich Blumenbach. He developed an interest in zoology, particularly ornithology...

, 1820)
1 Puff adder Most of sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

 south to the Cape of Good Hope
Cape of Good Hope
The Cape of Good Hope is a rocky headland on the Atlantic coast of the Cape Peninsula, South Africa.There is a misconception that the Cape of Good Hope is the southern tip of Africa, because it was once believed to be the dividing point between the Atlantic and Indian Oceans. In fact, the...

, including southern Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

, Mauritania
Mauritania
Mauritania is a country in the Maghreb and West Africa. It is bordered by the Atlantic Ocean in the west, by Western Sahara in the north, by Algeria in the northeast, by Mali in the east and southeast, and by Senegal in the southwest...

, Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...

, Mali
Mali
Mali , officially the Republic of Mali , is a landlocked country in Western Africa. Mali borders Algeria on the north, Niger on the east, Burkina Faso and the Côte d'Ivoire on the south, Guinea on the south-west, and Senegal and Mauritania on the west. Its size is just over 1,240,000 km² with...

, southern Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...

, Guinea
Guinea
Guinea , officially the Republic of Guinea , is a country in West Africa. Formerly known as French Guinea , it is today sometimes called Guinea-Conakry to distinguish it from its neighbour Guinea-Bissau. Guinea is divided into eight administrative regions and subdivided into thirty-three prefectures...

, Sierra Leone
Sierra Leone
Sierra Leone , officially the Republic of Sierra Leone, is a country in West Africa. It is bordered by Guinea to the north and east, Liberia to the southeast, and the Atlantic Ocean to the west and southwest. Sierra Leone covers a total area of and has an estimated population between 5.4 and 6.4...

, Ivory Coast, Ghana
Ghana
Ghana , officially the Republic of Ghana, is a country located in West Africa. It is bordered by Côte d'Ivoire to the west, Burkina Faso to the north, Togo to the east, and the Gulf of Guinea to the south...

, Togo
Togo
Togo, officially the Togolese Republic , is a country in West Africa bordered by Ghana to the west, Benin to the east and Burkina Faso to the north. It extends south to the Gulf of Guinea, on which the capital Lomé is located. Togo covers an area of approximately with a population of approximately...

, Benin
Benin
Benin , officially the Republic of Benin, is a country in West Africa. It borders Togo to the west, Nigeria to the east and Burkina Faso and Niger to the north. Its small southern coastline on the Bight of Benin is where a majority of the population is located...

, Niger
Niger
Niger , officially named the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east...

, Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

, Chad
Chad
Chad , officially known as the Republic of Chad, is a landlocked country in Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon and Nigeria to the southwest, and Niger to the west...

, Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...

, Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...

, Central African Republic
Central African Republic
The Central African Republic , is a landlocked country in Central Africa. It borders Chad in the north, Sudan in the north east, South Sudan in the east, the Democratic Republic of the Congo and the Republic of the Congo in the south, and Cameroon in the west. The CAR covers a land area of about ,...

, northern, eastern and southern Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...

, Uganda
Uganda
Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

, Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...

, Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...

, Rwanda
Rwanda
Rwanda or , officially the Republic of Rwanda , is a country in central and eastern Africa with a population of approximately 11.4 million . Rwanda is located a few degrees south of the Equator, and is bordered by Uganda, Tanzania, Burundi and the Democratic Republic of the Congo...

, Burundi
Burundi
Burundi , officially the Republic of Burundi , is a landlocked country in the Great Lakes region of Eastern Africa bordered by Rwanda to the north, Tanzania to the east and south, and the Democratic Republic of the Congo to the west. Its capital is Bujumbura...

, Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

, Angola
Angola
Angola, officially the Republic of Angola , is a country in south-central Africa bordered by Namibia on the south, the Democratic Republic of the Congo on the north, and Zambia on the east; its west coast is on the Atlantic Ocean with Luanda as its capital city...

, Zambia
Zambia
Zambia , officially the Republic of Zambia, is a landlocked country in Southern Africa. The neighbouring countries are the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west....

, Malawi
Malawi
The Republic of Malawi is a landlocked country in southeast Africa that was formerly known as Nyasaland. It is bordered by Zambia to the northwest, Tanzania to the northeast, and Mozambique on the east, south and west. The country is separated from Tanzania and Mozambique by Lake Malawi. Its size...

, Mozambique
Mozambique
Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...

, Zimbabwe
Zimbabwe
Zimbabwe is a landlocked country located in the southern part of the African continent, between the Zambezi and Limpopo rivers. It is bordered by South Africa to the south, Botswana to the southwest, Zambia and a tip of Namibia to the northwest and Mozambique to the east. Zimbabwe has three...

, Botswana
Botswana
Botswana, officially the Republic of Botswana , is a landlocked country located in Southern Africa. The citizens are referred to as "Batswana" . Formerly the British protectorate of Bechuanaland, Botswana adopted its new name after becoming independent within the Commonwealth on 30 September 1966...

, Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...

, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. Also occurs on the Arabian peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...

, where it is found in southwestern Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...

 and Yemen
Yemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....

.
B. atropos
Bitis atropos
Bitis atropos is a venomous viper species found only in mountainous regions in southern Africa. A small species. No subspecies are currently recognized.-Description:...

(Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...

, 1758)
0 Berg adder Isolated populations in the mountainous areas of southern Africa
Southern Africa
Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN...

: the Inyanga Highlands and Chimanimani Mountains
Chimanimani, Zimbabwe
Chimanimani is a mountainous area in the province of Manicaland, eastern Zimbabwe. The region is distinguished by large peaks,carved from a rifted quartzite block, the highest reaching to 2440 m and stretching for some 50 km , forming the border with Mozambique...

 of eastern Zimbabwe and nearby Mozambique, in South Africa along the Drakensberg Escarpments
Drakensberg
The Drakensberg is the highest mountain range in Southern Africa, rising to in height. In Zulu, it is referred to as uKhahlamba , and in Sesotho as Maluti...

 in the provinces of Transvaal, western Natal
Natal Province
Natal, meaning "Christmas" in Portuguese, was a province of South Africa from 1910 until 1994. Its capital was Pietermaritzburg. The Natal Province included the bantustan of KwaZulu...

, Lesotho
Lesotho
Lesotho , officially the Kingdom of Lesotho, is a landlocked country and enclave, surrounded by the Republic of South Africa. It is just over in size with a population of approximately 2,067,000. Its capital and largest city is Maseru. Lesotho is a member of the Commonwealth of Nations. The name...

 and eastern Free State
Free State
The Free State is a province of South Africa. Its capital is Bloemfontein, which is also South Africa's judicial capital. Its historical origins lie in the Orange Free State Boer republic and later Orange Free State Province. The current borders of the province date from 1994 when the Bantustans...

, and in the southern coastal mountains of western and eastern Cape Province
Cape Province
The Province of the Cape of Good Hope was a province in the Union of South Africa and subsequently the Republic of South Africa...

.
B. caudalis
Bitis caudalis
Bitis caudalis is a venomous viper species found in the arid region of south-west Africa. Easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized.-Description:...

(Smith
Andrew Smith (zoologist)
Sir Andrew Smith KCB was a Scottish surgeon, explorer, ethnologist and zoologist. He is considered the father of Zoology in South Africa having described many species across a wide range of groups in his major work, Illustrations of the Zoology of South Africa.Smith was born in Hawick, Roxburghshire...

, 1839)
0 Horned adder The arid region of south-west Africa: south-west Angola, Namibia, across the Kalahari Desert
Kalahari Desert
The Kalahari Desert is a large semi-arid sandy savannah in Southern Africa extending , covering much of Botswana and parts of Namibia and South Africa, as semi-desert, with huge tracts of excellent grazing after good rains. The Kalahari supports more animals and plants than a true desert...

 of southern Botswana, into northern Transvaal
Transvaal Province
Transvaal Province was a province of the Union of South Africa from 1910 to 1961, and of its successor, the Republic of South Africa, from 1961 until the end of apartheid in 1994 when a new constitution subdivided it.-History:...

 and southwestern Zimbabwe. In South Africa it is found from the northern Cape Province south to the Great Karoo.
B. cornuta
Bitis cornuta
Bitis cornuta is a venomous viper species found in certain rocky desert areas, mostly along the Atlantic coast of southern Africa. They have a characteristic tuft of horns above each eye. Two subspecies are currently recognized, including the nominate subspecies described here.-Description: Small...

(Daudin
François Marie Daudin
François Marie Daudin was a French zoologist.With legs paralyzed by childhood disease, he studied of physics and natural history, but ended up being devoted to the latter.Daudin wrote in 1799–1800...

, 1803)
1 Many-horned adder The coastal region of south-west Namibia through west and south-west Cape Province in South Africa. There are also a few isolated populations in eastern Cape Province.
B. gabonica
Bitis gabonica
Bitis gabonica is a venomous viper species found in the rainforests and savannas of Sub-Saharan Africa. This is not only the largest member of the genus Bitis, but also the world's heaviest viperid and it has the longest fangs ,and the highest venom yield of any venomous snake...

(Duméril
André Marie Constant Duméril
André Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...

, Bibron
Gabriel Bibron
Gabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...

 & Duméril
Auguste Duméril
Auguste Henri André Duméril was a French zoologist. He was professor of Herpetology and Ichthyology at the Muséum National d'Histoire Naturelle in Paris from 1857. His father André Marie Constant Duméril was also a zoologist...

, 1854)
1 Gaboon viper Guinea, Ghana, Togo, Nigeria, Cameroon, DR Congo, Central African Republic, southern Sudan, Uganda, Kenya, eastern Tanzania, Zambia, Malawi, eastern Zimbabwe, Mozambique, northeast KwaZulu-Natal Province
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....

 in South Africa.
B. heraldica
Bitis heraldica
Bitis heraldica is a venomous viper species found only in Angola. Easily distinguished from B. caudalis by its heavily speckled belly and lack of any supraocular horns. No subspecies are currently recognized.-Geographic range:...

(Bocage
José Vicente Barbosa du Bocage
José Vicente Barbosa du Bocage was a Portuguese zoologist and politician. He was the curator of Zoology at the Museum of Natural History in Lisbon. He published numerous works on mammals, birds, and fishes. In the 1880s he became the Minister of the Navy and later the Minister for Foreign Affairs...

, 1889)
0 Angolan adder The high plateau of central Angola.
B. inornata
Bitis inornata
Bitis inornata is a venomous viper species found only in Cape Province, South Africa. No subspecies are currently recognized.-Geographic range:...

(Smith, 1838) 0 Plain mountain adder Isolated population on the Sneeuberg, eastern Cape Province, South Africa.
B. nasicornis
Bitis nasicornis
Bitis nasicornis is a venomous viper species found in the forests of West and Central Africa. A big viper known for its striking color pattern and prominent horns on its nose. No subspecies are recognized.-Description:...

(Shaw
George Shaw
George Shaw was an English botanist and zoologist.Shaw was born at Bierton, Buckinghamshire and was educated at Magdalen Hall, Oxford, receiving his M.A. in 1772. He took up the profession of medical practitioner. In 1786 he became the assistant lecturer in botany at Oxford University...

, 1792)
0 Rhinoceros viper From Guinea to Ghana in West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...

, and in Central Africa
Central Africa
Central Africa is a core region of the African continent which includes Burundi, the Central African Republic, Chad, the Democratic Republic of the Congo, and Rwanda....

 in the Central African Republic, southern Sudan, Cameroon, Gabon, Congo, DR Congo, Angola, Rwanda, Uganda and western Kenya.
B. parviocula
Bitis parviocula
Bitis parviocula is a venomous viper species found only in south-west Ethiopia. It is large with a broad head and spectacular geometric markings. In 1995, the species was known from only three specimens, but additional information has surfaced since then. Little is known about its natural history...

Böhme, 1977 0 Ethiopian mountain adder Known from only five localities in the highlands to south-west Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

, at altitudes of 1700–2800 m.
B. peringueyi
Bitis peringueyi
Bitis peringueyi is a venomous viper species found in Namibia and southern Angola. No subspecies are currently recognized.-Description:A small snake with an average length of 20–25 cm and a maximum recorded length of 32 cm....

(Boulenger
George Albert Boulenger
George Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:...

, 1888)
0 Peringuey's desert adder The Namib Desert
Namib Desert
The Namib Desert is a desert in Namibia and southwest Angola that forms part of the Namib-Naukluft National Park, the largest game reserve in Africa. The name "Namib" is of Nama origin and means "vast place"...

 from southern Angola to Lüderitz, Namibia.
B. rubida
Bitis rubida
Bitis rubida is a venomous viper species found only in Western Cape Province, South Africa. No subspecies are currently recognized.-Geographic range:...

Branch, 1997 0 Red adder Several isolated populations in the northern Cape Fold Mountains and inland escarpment in Western Cape Province, South Africa.
B. schneideri
Bitis schneideri
Bitis schneideri is a venomous viper species found in a small coastal region that straddles the border between Namibia and South Africa. This is the smallest species in the genus Bitis and possibly the world's smallest viperid...

(Boettger
Oskar Boettger
Oskar Boettger was a German zoologist who was a native of Frankfurt am Main. He was an uncle of the noted malacologist Caesar Rudolf Boettger ....

, 1886)
0 Namaqua dwarf adder White coastal sand dunes from Namibia, near Lüderitz
Lüderitz
Lüderitz is a harbour town in south-west Namibia, lying on one of the least hospitable coasts in Africa. It is a port developed around Robert Harbour and Shark Island.- Overview :...

, south to Hondeklip Bay, Little Namaqualand
Namaqualand
Namaqualand is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of 170,000 square miles/440,000 km². It is divided by the lower course of the Orange River into two portions - Little Namaqualand to the south and Great Namaqualand to the...

, South Africa.
B. worthingtoni
Bitis worthingtoni
Bitis worthingtoni is a venomous viper species found only in the high central Rift Valley of Kenya. No subspecies are currently recognized.-Geographic range:Restricted to Kenya's high central Rift Valley at altitudes over 1,500 m...

Parker, 1932 0 Kenyan horned viper Restricted to Kenya's high central Rift Valley at altitudes over 1500 m.
B. xeropaga
Bitis xeropaga
Bitis xeropaga is a venomous viper species found in southern Namibia and north-western Cape Province in South Africa. No subspecies are currently recognized.-Description:Adults average 40–50 cm in length, with a maximum of 61 cm for a female....

Haacke, 1975 0 Desert mountain adder North-western Cape Province in South Africa and the arid mountains of the lower Orange River basin, north into to southern Namibia and Great Namaqualand
Namaqualand
Namaqualand is an arid region of Namibia and South Africa, extending along the west coast over and covering a total area of 170,000 square miles/440,000 km². It is divided by the lower course of the Orange River into two portions - Little Namaqualand to the south and Great Namaqualand to the...

 as far as Aus.
  • ) Not including the nominate subspecies.

T) Type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

.

Taxonomy

Other species may be encountered in literature, such as:
  • B. albanica - Hewitt, 1937
  • B. armata - Smith, 1826


Lenk et al. (1999) used molecular data (immunological distances and mitochondrial DNA sequences) to estimate the phylogenetic relationships among species of Bitis. They identified four major monophyletic groups for which they created four subgenera
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...

:
  • Bitis - B. arietans
    Bitis arietans
    Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...

  • Calechidna - B. albanica, B. armata, B. atropos
    Bitis atropos
    Bitis atropos is a venomous viper species found only in mountainous regions in southern Africa. A small species. No subspecies are currently recognized.-Description:...

    , B. caudalis
    Bitis caudalis
    Bitis caudalis is a venomous viper species found in the arid region of south-west Africa. Easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized.-Description:...

    , B. cornuta
    Bitis cornuta
    Bitis cornuta is a venomous viper species found in certain rocky desert areas, mostly along the Atlantic coast of southern Africa. They have a characteristic tuft of horns above each eye. Two subspecies are currently recognized, including the nominate subspecies described here.-Description: Small...

    , B. heraldica
    Bitis heraldica
    Bitis heraldica is a venomous viper species found only in Angola. Easily distinguished from B. caudalis by its heavily speckled belly and lack of any supraocular horns. No subspecies are currently recognized.-Geographic range:...

    , B. inorata
    Bitis inornata
    Bitis inornata is a venomous viper species found only in Cape Province, South Africa. No subspecies are currently recognized.-Geographic range:...

    , B. peringueyi
    Bitis peringueyi
    Bitis peringueyi is a venomous viper species found in Namibia and southern Angola. No subspecies are currently recognized.-Description:A small snake with an average length of 20–25 cm and a maximum recorded length of 32 cm....

    , B. rubida
    Bitis rubida
    Bitis rubida is a venomous viper species found only in Western Cape Province, South Africa. No subspecies are currently recognized.-Geographic range:...

    , B. schneideri
    Bitis schneideri
    Bitis schneideri is a venomous viper species found in a small coastal region that straddles the border between Namibia and South Africa. This is the smallest species in the genus Bitis and possibly the world's smallest viperid...

    , B. xeropaga
    Bitis xeropaga
    Bitis xeropaga is a venomous viper species found in southern Namibia and north-western Cape Province in South Africa. No subspecies are currently recognized.-Description:Adults average 40–50 cm in length, with a maximum of 61 cm for a female....

  • Macrocerastes - B. gabonica
    Bitis gabonica
    Bitis gabonica is a venomous viper species found in the rainforests and savannas of Sub-Saharan Africa. This is not only the largest member of the genus Bitis, but also the world's heaviest viperid and it has the longest fangs ,and the highest venom yield of any venomous snake...

    , B. nasicornis
    Bitis nasicornis
    Bitis nasicornis is a venomous viper species found in the forests of West and Central Africa. A big viper known for its striking color pattern and prominent horns on its nose. No subspecies are recognized.-Description:...

    , B. parviocula
    Bitis parviocula
    Bitis parviocula is a venomous viper species found only in south-west Ethiopia. It is large with a broad head and spectacular geometric markings. In 1995, the species was known from only three specimens, but additional information has surfaced since then. Little is known about its natural history...

  • Keniabitis - B. worthingtoni
    Bitis worthingtoni
    Bitis worthingtoni is a venomous viper species found only in the high central Rift Valley of Kenya. No subspecies are currently recognized.-Geographic range:Restricted to Kenya's high central Rift Valley at altitudes over 1,500 m...



For now, this division is of little consequence as far as the nomenclature is concerned. However, the definition of subgenera within a genus is often the sign of an impending split. Therefore, anyone interested in these snakes would do well to familiarize themselves with these new subgenera.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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