Xenocalamus bicolor
Subspecies X. bicolor bicolor
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Atractaspididae
Genus: Xenocalamus
Species:
X. bicolor
Binomial name
Xenocalamus bicolor
Günther, 1868

Xenocalamus bicolor, also known commonly as the bicoloured quill-snouted snake and the slender quill-snouted snake, is a species of mildly venomous rear-fanged snake in the family Atractaspididae.[2] The species is endemic to Africa.[3] Four subspecies are recognized as being valid.

Geographic range

X. bicolor is found in Angola, Botswana, Democratic Republic of the Congo, Mozambique, Namibia, Republic of South Africa, and Zimbabwe.[3]

Habitat

The preferred natural habitat of X. bicolor is savanna, at altitudes of 900–1,400 m (3,000–4,600 ft).[1]

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 43 cm (16+7⁄8 in); tail 3 cm (1+1⁄8 in).

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.[4]

(Nota bene: the description above is a description of the species X. bicolor. The subspecies listed below vary somewhat from this description.)

Subspecies

Four subspecies are recognized including the nominate race.[3]

  • Xenocalamus bicolor australis V. FitzSimons, 1946
  • Xenocalamus bicolor bicolor Günther, 1868
  • Xenocalamus bicolor lineatus Roux, 1907
  • Xenocalamus bicolor machadoi Laurent, 1954

Behaviour

X. bicolor is terrestrial and fossorial, burrowing in aeolian and alluvial sands.[1]

Diet

X. bicolor preys predominately upon amphisbaenians.[5]

Reproduction

X. bicolor is oviparous.[3] Eggs are laid in December.[5] Clutch size is 3–4 eggs.[5] The eggs are elongate, approximately 4.5 cm × 1.5 cm (1.77 in × 0.59 in).[5] Each hatchling has a total length (including tail) of 20 cm (7.9 in).[5]

References

  1. 1 2 3 Alexander GJ, Tolley KA (2021). "Xenocalamus bicolor ". The IUCN Red List of Threatened Species 2021: https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T110133231A110239956.en. Accessed on 31 March 2023.
  2. ↑ "Xenocalamus". Integrated Taxonomic Information System. Retrieved 29 August 2007.
  3. 1 2 3 4 Xenocalamus bicolor at the Reptarium.cz Reptile Database. Accessed 12 May 2009.
  4. ↑ 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).
  5. 1 2 3 4 5 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. ISBN 0-88359-042-5. (Genus Xenocalamus, p. 67; X. bicolor, p. 68).

Further reading

  • FitzSimons V (1946). "Notes on some African snakes, including a description of a new subspecies of Xenocalamus ". Annals of the Transvaal Museum 20 (4): 379–394. (Xenocalamus bicolor australis, new subspecies, p. 386).
  • Günther A (1868). "Sixth Account of new Species of Snakes in the Collection of the British Museum". Annals and Magazine of Natural History, Fourth Series 1: 413–429. (Xenocalamus bicolor, new species, p. 415 + Plate XIX, figure A).
  • Laurent R (1954). "Reptiles et batraciens de la région de Dundo (Angola) (Duexième note)". Companhia de Diamantes de Angola (Diamang), Serviços Culturais, Publicações Culurais (23): 37–84. (Xenocalamus bicolor machadoi, new subspecies, p. 45). (in French).
  • Roux J (1907). "Sur quelques Reptiles sud-africains ". Revue suisse de zoologie 15: 75–86. (Xenocalamus bicolor var. lineatus, new "variety", pp. 79–80). (in French).



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