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 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

Xenocalamus bicolor Xenocalamus generoko animalia da. Narrastien barruko Atractaspididae familian sailkatuta dago.

Erreferentziak

• TIGR Reptile Database in Species 2000 and ITIS Catalogue of Life: 2011 Annual Checklist

Ikus, gainera

• Xenocalamus
• Atractaspididae

Xenocalamus bicolor est une espèce de serpents de la famille des Lamprophiidae^[1].

Répartition

Cette espèce se rencontre^[1] :

• en Afrique du Sud ;
• en Angola ;
• au Botswana ;
• au Mozambique ;
• en Namibie ;
• en République démocratique du Congo ;
• au Zimbabwe.

Liste des sous-espèces

Selon Reptarium Reptile Database (2 déc. 2011)^[2] :

• Xenocalamus bicolor australis FitzSimons, 1946
• Xenocalamus bicolor bicolor Günther, 1868
• Xenocalamus bicolor concavorostralis Hoffman, 1940
• Xenocalamus bicolor lineatus Roux, 1907
• Xenocalamus bicolor machadoi Laurent, 1954
• Xenocalamus bicolor maculatus FitzSimons, 1937
• Xenocalamus bicolor pernasutus (Werner, 1915)

Description

L'holotype de Xenocalamus bicolor^[3] mesure 43 cm toutefois sa queue est incomplète. Son dos est uniformément noir et sa face ventrale blanche.

C'est un serpent venimeux^[1].

Étymologie

Son nom d'espèce, du latin bicolor, « à deux couleurs », lui a été donné en référence à sa livrée.

Publications originales

• FitzSimons, 1946 : Notes on some South African snakes, including a description of a new subspecies of Xenocalamus. Annals of the Transvaal Museum, vol. 20, n^o 4, p. 379-393.
• Günther, 1868 : Sixth account of new species of snakes in the collection of the British Museum. Annals and Magazine of Natural History, sér. 4, vol. 1, p. 413-429 (texte intégral).
• Hoffman, 1940 : A new subspecies of Xenocalamus from Bloemfontein. Soölogiese navorsing van die Nasionale Museum, vol. 1, n^o 11, p. 111-112.
• Laurent, 1954 : Reptiles et batraciens de la région de Dundo (Angola) (Deuxième note). Companhia de Diamantes de Angola (Diamang), Serviços Culturais, Publicações Culturais, n^o 23, p. 37-84.
• Roux, 1907 : Sur quelques reptiles sud-africains. Revue suisse de zoologie, vol. 15, p. 75-86 (texte intégral).
• Werner, 1915 : Reptilia und Amphibia in Michaelsen, 1915 : Beiträge zur Kenntnis der Land- und Süsswasserfauna Deutsch-Südwestafrikas, vol. 3, p. 325-376 (texte intégral).

Notes et références