Gabon Viper Eastern Green Mamba
© AMNH / Denis Finnin
Two snakes, each with a different deadly venom. But both snakes would rather slip away from you than strike.
Huge fangs--more than four centimeters (1.5 inches) long in adults--fold inside the mouth. When the snake gapes to strike, the bone to which the fang is attached swings up and out, erecting the fang.
Most snake venoms are a "soup" of enzymes with harmful effects--on blood, on nerves, on tissues. This viper's venom acts mostly on tissues, destroying cells and causing uncontrolled bleeding. The snake strikes, injects its venom and withdraws its fangs. Its prey escapes . . . but not for long.
With its massive body and short tail, the Gabon Viper moves slowly along the ground. But it strikes with lightning speed from a resting position.
© AMNH / Denis Finnin
Eastern Green Mamba
The vertical pupil is one clue that this snake is active at night. In daylight the animal rests among the dead leaves on the forest floor, where its body coloring makes it nearly invisible.
This slender, fast-moving snake lives in the treetops, where its vivid green-and-black color is good camouflage. It is the largest of the tree-dwelling mambas.
Mambas have short fangs that don't swing out as much as the fangs of vipers. The Eastern Green Mamba's powerful venom attacks the nervous system. That means it affects breathing, muscle control and, in human victims, speech.
© Michael & Patricia Fogden / Minden Pictures
Eyelash Viper (Bothriechis schlegelii), gold morph camouflaged among palm fruits
Puff AdderBitis arietans
The Puff Adder is a large snake with highly toxic venom. It is responsible for most of the serious bites, some fatal, in southern Africa. The Puff Adder holds the world record for number of offspring for any snake, up to 156 live young. When disturbed, it assumes a strike posture and gives deep, hollow hiss.
Meet the Families
Viperidae, with more than 250 species, is a varied family of venomous snakes. The fangs of snakes in this family erect to bite and fold back against the roof of the mouth when not in use. Some vipers--such as rattlesnakes--have heat-sensing pits for prey detection.
The family that includes cobras, sea snakes and relatives is called Elapidae. Its members live on every continent but Antarctica. They are especially common in Australia.
NAME: Gabon Viper; Bitis gabonica
SIZE: 1.8 meters (6 feet); 10 kilograms (22 pounds)
RANGE: Tropical Africa
DIET: Small mammals
NAME: Eastern Green Mamba; Dendroaspis angusticeps
SIZE: up to 2.3 meters (7.5 feet)
RANGE: Eastern and southeastern Africa
DIET: Birds, rodents, bats