Spiny Bush Viper

Its body scales are strongly keeled, meaning each scale has a raised ridge down the centre, and on much of the body, particularly around the head and neck, the scales are also elongated and angled so that they stand out from the skin instead of lying smooth. The overall effect is a rough, spiky, almost furry texture quite unlike the sleek look of most snakes. The function is not fully understood. Suggestions include breaking up the snake's outline among leaves and twigs, shedding rain or dew, and reducing shine, but none is firmly established, and the trait may simply be an extreme version of the keeled scales common in the bush viper group.

Potentially serious, but bites are extremely rare. The venom mainly interferes with blood clotting and can also cause local pain, swelling, blistering, and tissue damage, and severe envenomation can lead to internal bleeding. However, the snake lives in remote, thinly populated forest, is small, is not aggressive, and delivers relatively little venom, so almost the only people bitten are keepers handling captive specimens. There is no antivenom made specifically for Atheris species, which complicates treatment of the worst cases, and medical management focuses on supporting clotting and organ function while the effects wear off.

It is found only in parts of Central Africa, in a scattered set of populations across the eastern Democratic Republic of the Congo, Uganda, western Kenya, Rwanda, and northwestern Tanzania. Within that region it favours rainforest, the edges and clearings of forest, and swampy grassland and reed beds, generally close to water and generally where there is dense low vegetation to climb through. It is a lowland to mid-altitude species and is not spread evenly, turning up in some suitable-looking areas and not others, which makes it hard to survey.

It is a snake for very experienced venomous-reptile keepers only, and in many places keeping one requires a licence. It is delicate in captivity, needing carefully controlled humidity, temperature, ventilation, and live or scented prey, and it is prone to stress and to respiratory and other health problems if conditions are wrong. On top of the husbandry difficulty, any bite is a medical emergency with no species-specific antivenom available. For the overwhelming majority of people interested in the species, it is best appreciated through photographs and the work of specialist institutions rather than kept.