''Xenocalamus bicolor'', also known commonly as the bicoloured quill-snouted snake and the slender quill-snouted snake, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of mildly

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 ...

rear-fanged A snake skeleton consists primarily of the skull, vertebrae, and ribs, with only vestigial remnants of the limbs. Skull The skull of a snake is a very complex structure, with numerous joints to allow the snake to swallow prey far larger than it ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Atractaspididae The Atractaspididae (atractaspidids) are a Family (biology), family of venomous snakes found in Africa and the Middle East, commonly called mole vipers, stiletto snakes, or burrowing asps. Currently, 12 genus, genera are recognized. Description ...

. The species is

endemic Endemism is the state of a species being found only 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 foun ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

. Four

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognized as being valid.

Geographic range

''X. bicolor'' is found in

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

Botswana Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory part of the Kalahari Desert. It is bordered by South Africa to the sou ...

Democratic Republic of the Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...

Mozambique Mozambique, officially the Republic of Mozambique, is a country located in Southeast Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west, and Eswatini and South Afr ...

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

Republic of South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

, and

Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...

Habitat

The preferred natural

habitat In ecology, habitat refers to the array of resources, 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 manifestation of its ...

of ''X. bicolor'' is

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

, at altitudes of .

Description

''X. bicolor'' exhibits the following characters: Black dorsally. White ventrally including the upper lip and the first two rows of dorsal scales on each side. Total length ; tail . Dorsal scales smooth, without apical pits, arranged in 17 rows. Ventrals 218; anal plate divided; subcaudals 24, also divided. Portion of rostral visible from above nearly half as long as the frontal. Frontal extremely large, more than half as long as the shielded part of the head. Internasals large, forming a short median suture. Supraocular very narrow. One large elongate preocular, contacting the posterior nasal, the internasal, the frontal, and the third upper labial. One minute postocular. One temporal. Six upper labials, the first very small, third and fourth entering the eye, the fifth very large and contacting the parietal. One pair of narrow chin shields. Three lower labials in contact with the chin shield. Third lower labial extremely large. Boulenger GA (1896). ''Catalogue of the Snakes in the British Museum (Natural History), Volume III''. London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiv + 727 pp. + Plates I-XXV. (''Xenocalamus bicolor'', p. 248). (''

Nota bene ( ; plural: ) is the Latin language, Latin phrase meaning ''note well''. In manuscripts, ''nota bene'' is abbreviated in upper-case as NB and N.B., and in lower-case as n.b. and nb; the editorial usages of ''nota bene'' and ''notate bene'' fi ...

'': the description above is a description of the

''X. bicolor''. The

listed below vary somewhat from this description.)

Subspecies

Four subspecies are recognized including the

nominate race In biological classification, subspecies (: 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. ...

. *'' Xenocalamus bicolor australis'' *'' Xenocalamus bicolor bicolor'' *''

Xenocalamus bicolor lineatus :''Common name: quill-snouted snakes.'' ''Xenocalamus'' is a genus of Opisthoglyphous, rear-fanged mildly venomous snakes in the Family (biology), family Atractaspidinae, Atractaspididae. The genus is Endemism, endemic to Africa. Five species ar ...

'' *''

Xenocalamus bicolor machadoi :''Common name: quill-snouted snakes.'' ''Xenocalamus'' is a genus of rear-fanged mildly venomous snakes in the family Atractaspididae. The genus is endemic to Africa. Five species are recognized as being valid. Description (diagnosis) of genus ...

Behaviour

''X. bicolor'' is

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

and

fossorial A fossorial animal () is one that is adapted to digging and which lives primarily (but not solely) underground. Examples of fossorial vertebrates are Mole (animal), moles, badgers, naked mole-rats, meerkats, armadillos, wombats, and mole salamand ...

, burrowing in aeolian and alluvial sands.

Diet

''X. bicolor'' preys predominately upon

amphisbaenians Amphisbaenia (called amphisbaenians or worm lizards) is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As ...

Reproduction

''X. bicolor'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

. Eggs are laid in December.

Clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

size is 3–4 eggs. The eggs are elongate, approximately . Each hatchling has a total length (including tail) of . Branch, Bill (2004). ''Field Guide to Snakes and other Reptiles of Southern Africa''. Third Revised edition, Second impression. Sanibel Island, Florida: Ralph Curtis Books. 399 pp. . (Genus ''Xenocalamus'', p. 67; ''X. bicolor'', p. 68).

References

External links

iNaturalist link
Atractaspididae Taxa named by Albert Günther Reptiles described in 1868 {{snake-stub