Rinkhals
| Rinkhals | |
|---|---|
 |
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| Hemachatus haemachatus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Subphylum: | Vertebrata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Elapidae |
| Genus: | Hemachatus Fleming, 1822 |
| Species: | H. haemachatus |
| Binomial name | |
| Hemachatus haemachatus (Bonnaterre, 1790) |
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| Synonyms | |
The Rinkhals (Hemachatus haemachatus), also called the Ringhals or Ring-necked spitting cobra, is a venomous elapid species found in parts of southern Africa. It is not a true cobra in that it does not belong to the genus Naja, but instead belongs to the monotypic genus Hemachatus. However, it is closely related to the true cobras and is considered to be one of the true spitting cobras.[3].
Contents |
[edit] Description
Coloration varies throughout its distribution area but characteristic of the species is that the belly is dark and there are 1-2 light coloured crossbands on the throat.
Average length is 90 - 110cm. [3] Some individuals may have a mostly black body while others are striped. Rinkhals scales are distinct from that of true cobras in that they are ridged and keel-like.
[edit] Scale pattern and distribution
- dorsal scales are keeled[5]
- 17-19 rows of dorsal scales at midbody
- 116-150 ventrals
- anal plate is entire
- 30-47 subcaudals
- subcaudals are paired
- 7 upper labials
- upper labials 3 and 4 entering the eye
- 1 preocular (rarely up to 3)
- 3 postoculars
- 8-9 lower labials
[edit] Distribution
Southern Cape province of South Africa, N.E through the Free State, Lesotho, Transkei, Kwazulu Natal,South Africa, Western Swaziland and parts of Gauteng, South Africa. An isolated population is centered around Inyanga on the Zimbabwe / Mozambique border. [3]
[edit] Behaviour and diet
The Rinkhals has eclectic tastes. Its main prey is toads,[4] but it also eats small mammals, amphibians, and other reptiles.[6] Like several other snakes, the Rinkhals is also known for its ability to play dead.
[edit] Venom
The venom of the Rinkhals is neurotoxic and partially cytotoxic. The venom of this species is less viscous than that of other African elapids.[3] It generally aims its venom at the face. If the venom enters the eyes it causes great pain.[6]
[edit] Symptoms of a bite
Local symptoms of swelling / bruising is reported in about 25% of cases.[3] General symptoms of drowsiness, nausea, vomiting, violent abdominal pain, cramps and vertigo often occur, as does a mild pyrexial reaction.[3][6]
[edit] Defensive behaviour
When distressed the Rinkhals spreads its hood, showing its distinctive striped neck. The Rinkhals is a spitting snake, and can spray its venom up to 2.5m. Its spitting mechanism is primitive and it has to rear up and fling its body forward in order to spray its venom. It is also known to fake death by rolling onto its back with its mouth agape.
[edit] Habitat
The Rinkhals generally prefers grassland habitats because it makes them blend in with the surroundings. Rinkhals also may live in swamps around Southern Africa.[6]
[edit] Interesting facts
- The Rinkhals is one of the few snakes on Earth that, when sensing a predator is near, will pretend to be dead.
- The Rinkhals is not in the same genus as other "true" cobras, it is in fact monotypic and not in the genus Naja. Nevertheless, many experts consider it to be one of the true "spitters" - as spitting goes among snakes.[3]
- Rinkhals are unique amongst African cobras in being ovoviviparous.[3] They give birth to 20-35 young, but as many as 65 babies have been recorded.[4]
[edit] References
- ^ Boulenger, G.A. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ)... Trustees of the British Museum (Natural History). London. p. 389.
- ^ The Reptile Database. www.reptile-database.org.
- ^ a b c d e f g h S. Hunter (2000). "Venomous Reptiles". http://www.venomousreptiles.org/articles/34.
- ^ a b c R. Mastenbroek (2002). "Rinkhals". http://www.kingsnake.com/elapids/rinkhals_spitting_cobra.htm.
- ^ Branch, Bill. 2004. Field Guide to Snakes and Other Reptiles of Southern Africa, Third Revised edition, Second impression. Ralph Curtis Books. Sanibel Island, Florida. 400 pp. ISBN 0-88359-042-5.
- ^ a b c d B. Branch (1988). Field Guide to the Snakes and Other Reptiles of southern Africa. Struik, Cape Town.
