Rinkhals

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Rinkhals
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)

The Rinkhals also called the Ringhals or Spitting cobra (Hemachatus haemachatus) is a venomous elapid species found in parts of southern Africa. It is one of a group of cobras that has developed the ability to spit venom as a defense mechanism.

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[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.

A South African Rinkhals with hood spread.
A South African Rinkhals with hood spread.

Average length is 90 - 110cm[1]. Another way to identify a Rinkhals is that its scales are ridged and keel-like.

[edit] Scale Pattern and Distribution

Scalation:[2]

  • 17 -19 Dorsal scales on the midbody
  • 116-150 Ventrals
  • 30-47 Subcaudals
  • Subscales are paired
  • Analscale is entire
  • 7 Upper labials
  • 3+4 Upper labials entering the eye
  • 1 Preoculair (rarely up to 3)
  • 3 Postoclurairs
  • 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[1].

[edit] Behaviour and Diet

The Rinkhals has eclectic tastes. Its main prey is toads[2], but it also eats small mammals, reptiles and other amphibians[3]. 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 cytotoxicity. The venom of this species is less viscous than that of other African elapids[1]. It generally aims its venom at the face. If the venom enters the eyes it causes great pain[3].

[edit] Symptoms of a Bite

Local symptoms of swelling / bruising is reported in about 25% of cases[1]. General symptoms of drowsiness, nausea, vomiting, violent abdominal pain, cramps and vertigo often occur, as does a mild pyrexial reaction[1][3].

[edit] Defensive behaviour

When distressed the Rinkhals spreads its hood, showing its distinctive striped neck. The Rinkhals is commonly believed to be a form of spitting cobra as it is able to spray its venom, that up to 2.5m[3]. This, however, is not true. Although it is in the Rinkhals' capacity to spray its venom and its venom is neurotoxic, it is not a cobra. It is also known to fake death by rolling onto its back with its mouth agape.

Close up of the front of a Rinkhals. Note the characteristic stripes across the neck.
Close up of the front of a Rinkhals. Note the characteristic stripes across the neck.

[edit] Habitat

The Rinkhals generally prefers grassland habitas[3].

[edit] Interesting Facts

  • 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[1].
  • Rinkhals are unique amongst African cobras in being ovoviviparous[1]. They give birth to 20-35 young, but as many as 65 babies have been recorded:[2].
  • The Rinkhals is unique also, compared to cobras, as it has keeled scales.

[edit] References

  1. ^ a b c d e f g S. Hunter (2000). Venomous Reptiles.
  2. ^ a b c R. Mastenbroek (2002). Rinkhals.
  3. ^ a b c d e B. Branch (1988). Field Guide to the Snakes and Other Reptiles of southern Africa. Struik, Cape Town.