Out of the more than 2,900 species of snakes in the world about 600 species only are known to be venomous. Venomous snakes have highly specialized teeth such as hollow fangs, through which they deliver venom to immobilize prey, or for self-defense. A venomous snake bite quickly affects different organs including the lungs, heart, central nervous system, red blood cells and muscles. Venom can be neurotoxic, haemotoxic or myotoxic.
Though Australia is known to be home to the majority of the world's most venomous snakes, Africa has its share of potentially highly dangerous species: here are the main ones.
Among the most notable attributes of the dreaded cobras are their powerful - often deadly - venom and their hood that can enlarge. Here are some notably poisonous species of African cobras.
- Egyptian Cobra (Naja haje)
The most common cobra in Africa occurs from the Sahara Desert to the Syrian Desert and can measure up to 8 ft (2.4 meters). It is responsible for many deaths.
When threatened, it raises the front part of its body and spreads its neck into a hood. It will continue attacking until it feels an escape is possible.
The extremely strong venom of the Egyptian cobra is neurotoxic: it destroys nerve tissue, causing paralysis and death due to respiratory failure, usually within 15 minutes.
This venom is used in medical research because it has an enzyme, lecithinase, that dissolves cell walls and membranes surrounding viruses.
- Cape Cobra (Naja nivea)
- Forest Cobra (Naja melanoleuca)
This large snake from the tropical and subtropical rain forests of Western, Central, Eastern and Southern Africa is sometimes considered to be the least dangerous of the Najas. Its bite, however, can be rapidly fatal without prompt intervention.
- Gold's Tree Cobra (Pseudohaje goldii) and Black Tree Cobra (Pseudohaje nigra)
These two large and primarily arboreal species are found in the forests of tropical Africa. They have a reputation for being particularly ill-tempered and have an extremely toxic venom.
- Ashe's Spitting Cobra (Naja ashei)
This aggressive and extremely venomous snake can grow to more than 9 feet (274 centimeters) long, making it the largest spitting cobra.
- Red Spitting Cobra (Naja pallida)
Common in northeast Africa, (Nile valley, Ethiopia, Eritrea and Somalia), these nocturnal snakes can spit venom at 2 m(7 feet).
- Mozambique Spitting Cobra (Naja mossambica)
Possibly the most dangerous snake in Africa after the Mamba. This southeast African snake is nervous and highly strung. When confronted at close quarters it can rear up two-thirds of its length, spread its long narrow hood and will readily "spit" in defense.
- Black Spitting Cobra (Naja nigricollis)
Occurring throughout Africa, this snake rarely spits but is capable of atomizing venom accurately to a distance of up to 20 feet. Though usually shy, it will bite unpredictably, its neurotoxic venom causing grave tissue damage often requiring amputation of a limb or provoking death.
- West African Brown Spitting Cobra (Naja katiensis)
A small spitter occurring in the dry savannas of West Africa.
- Ringhal or Rinkhal (Hemachatus haemachatus)
Found in southern Africa, this spitting cobra is the smallest and the only ovoviviparous (giving birth to live young) of the cobras.
Mambas are close cousins to the cobras. They are extremely poisonous snakes with the (deserved) reputation of being very aggressive. There are only a few species in Africa.
- Black Mamba (Dendroaspis polylepis)
The black mamba is much more terrestrial than the other three species of mamba, though it does climb trees in search of prey and to bask or seek shelter.
It is an aggressive snake that springs up to strike when not able to escape, so when someone gets bitten, it's usually on the head. After biting its prey, often multiple times, a black mamba leaves it to die, which only takes minutes thanks to its amazingly strong venom.
The bite of the black mamba is deadly and will kill a human in roughly 4 hours. The venom is neurotoxic and cardiotoxic. If not treated the symptoms include: a tightening of the chest muscles, blurred vision, mental confusion, and an overall feeling of great discomfort. Before antivenin was available the bite of a black mamba was always fatal.
- Green Mamba or Eastern Green Mamba (Dendraspis angusticeps)
Occurring in the coastal regions of southeast Africa, this long slender arboreal mamba, is considered one of the most dangerous snakes in the world. It is aggressive and has a highly neurotoxic venom: its victim has little chance to escape from a bite.
- West African Green Mamba (Dendroaspis viridis)
A green and black mamba living in the forests of West Africa.
- Jameson's Mamba (Dendroaspis jamesoni)
A duller green forest snake occurring in much of equatorial Africa.
Many Adders or Vipers occur throughout Africa, and mainly southern Africa, most of them are not deadly, though they remain highly poisonous.
- Puff Adder (Bitis arietans)
This is one of the front-fanged snakes. When it strikes, the fangs fold forward and inject a cytotoxic venom deep into the prey. Even when one the victim is treated with an anti-venom, the damage done to the body tissues is often tremendous.
- Gaboon Viper or Gaboon Adder (Bitis gabonica)
The largest African viper, occurring in forests on most of the continent. This snake has a striking coloration and pattern that nevertheless offers it camouflage.
It can be longer than 6 feet (2 m) and weigh more than 15 pounds (6.8 kg). The fangs of a large adult may exceed two inches (5 cm) in length.
It bites when molested or stepped on and injects large amounts of a venom that is both neurotoxic and haemotoxic. With the puff adder, the Gaboon adder has the most dangerous venom of the African vipers.
- Rhinoceros Viper or Rhinoceros-horned Viper (Bitis nasicornis)
A large heavy bodied viper with a prominent nasal horn found in the forests of equatorial Africa. Its beautiful color and pattern make it invisible on the forest floor.
- Berg Adder (Bitis atropos),
This small southern African snake, unlike most vipers, has a major neurotoxic venom that affects the eyes and other sensory functions and is not neutralized by existing antivenom.
- Western Bush Viper or West African Bush Viper, or Green Bush Viper
Found in the forests of West Africa from Guinea east to Gabon.
This slender bush viper is relatively large: 45-60 cm (18-24 inches).
This species is largely arboreal and is often found in low bushes and shrubs in rain forests at altitudes of up to 560 meters.
- Bush Viper or Leaf Viper (Atheris squamiger)
This arboreal snake occurs throughout Africa: Angola, Cameroon, Uganda, Kenya, DRC... It uses its prehensile tail to secure itself to branches. It is not aggressive and though its haemotoxic venom is strong, healthy adults rarely die from its bite.
Other African adder species include: the Albany Adder (Bitis albanica); the Southern Adder (Bitis armata) found in South Africa; the Horned Adder (Bitis caudalis) from the Namib and Kalahari deserts; the Many Horned Adder (Bitis cornuta) found along southern Africa's western coast; the rare Angolan Adder ( Bitis heraldica); the Plain Mountain Adder (Bitis inornata) found in the Cape Province, South Africa; the Ethiopian Mountain Adder (Bitis parviocula); Peringuey's Adder (Bitis peringueyu) found in the Namib desert; the Red Adder (Bitis rubida) found in the Western Cape Province of South Africa; the tiny Namaqua Dwarf Adder (Bitis schneideri) of Namibia; Kenya Horned Viper (Bitis worthingtoni); the Desert Mountain Adder (Bitis xerophaga) of Southern Africa; the Lowland Swamp Viper (Atheris superciliaris) of eastern Africa, the Common or Rhombic Night Adder (Causus rhombeatus) and the Snouted Night Adder (Causus defilippii) of southeastern Africa; theSaharan Sand Vipers (Cerastes vipera), the Saw Scaled (Carpet) Viper (Echis Merrem), the Painted Carpet Viper (Echis coloratus), the White-bellied Carpet Viper (Echis leucogaster), the West African Carpet Viper (Echis ocellatus), the Northeast Africa Carpet Viper (Echis pyramidum). Carpet vipers are very dangerous because they are irascible, have a very virulent venom and often strike repeatedly.
There are a number of other types of venomous snakes in Africa, though only the following two are seen as potentially mortal to humans (at least to healthy adults):
- Boomslang (Dispholidus typus)
- Bird or Twig Snake (Theolotornis capensis)
Occuring in eastern and southern Africa, this extremely thin arboreal snake has a strong haemotoxic venom with similar symptoms to that of the boomslang but which is not neutralized by the boomslang-specific antivenom.
Branch, Bill, Snakes and other Reptiles of Southern Africa, Struik, Cape Town, 1996
Top 15 Most Venomous Cobras in the World
Venomous Snakes of Liberia and West Africa
Venomous Snakes of Africa