The rinkhals, also called the ringhals or ring-necked spitting cobra, is a species of venomouselapid found in parts of southern Africa. It is not a true cobra in that it does not belong to the genusNaja, but instead belongs to the monotypic genusHemachatus. While rinkhals bear a great resemblance to true cobras they also possess some remarkable differences from these, resulting in their placement outside the genus Naja.
Description
Colouration varies throughout its distribution area, but a characteristic of the species is the belly is dark with one or two light-coloured crossbands on the throat. Their average length is 90–110 cm. Some individuals may have a mostly black body, while others are striped. Rinkhals scales are distinct from those of Naja cobras in that they are ridged and keel-like.
The rinkhals has a varied diet. Its main prey is toads, but it also eats small mammals, amphibians, and other reptiles. Rinkhals are unique amongst African cobras in being ovoviviparous. They give birth to 20–35 live young, but as many as 65 young have been recorded.
Venom
The venom of the rinkhals is neurotoxic and partially cytotoxic, and is less viscous than that of other African elapids. When confronting a human, it generally aims its venom at the face. If the venom enters the eyes, it causes great pain. A polyvalent antivenom is currently being developed by the Universidad de Costa Rica's Instituto Clodomiro Picado
Symptoms of a bite
Local symptoms of swelling and bruising is reported in about 25% of cases. General symptoms of drowsiness, nausea, vomiting, violent abdominal pain, cramps and vertigo often occur, as does a mild pyrexial reaction.
Defensive behaviour
If distressed, the rinkhals spreads its hood, showing its distinctive, striped neck. It is a spitting cobra, and can spray its venom up to 2.5 m. Its spitting mechanism is primitive and it has to rear up and fling its body forward to spray its venom. It is also known to fake death by rolling onto its back with its mouth agape.
Habitat
The rinkhals generally prefers grassland habitats because it allows them to blend in with the surroundings. Rinkhals also may live in swamps around southern Africa.