Venomous Snakes of Guyana

Two Families - Viperidae & Elapidae

Vipers

These are hinged-fanged venomous snakes. Their fangs are designed to be very long so they can penetrate deeply yet be stored against the roof of the mouth when not in use. There are four genera and six species of vipers in Guyana - Bothriopsis, Bothrops, Crotalus, and Lachesis. Vipers are distinctive because of their heavy bodies, short tails, and a triangularly shaped head. Their scales are often keeled.

The most famous of the vipers in Guyana is the Bushmaster (Lachesis muta). This snake is aptly named in English and particularly in Latin - as the "silent bringer of death." The bushmaster, known as the surucucu in Brazil, and the shushupe in other countries, is the largest venomous snake in the New World. These snakes can regularly exceed 2,000 millimetres in length (6.5 ft.), and one of the largest recorded was 4,267 mm (14 ft.)! Like the rattlesnake, it has a prominent dorsal ridge, and the head is broad with an upturned snout. The bushmaster is a nocturnal snake, and reported as extremely aggressive, although scientists believe this to be an exaggeration.

Bushmaster

Lachesis muta

The genus Bothriopsis includes two small forest pit vipers in Guyana. The better known of these is the Guyanese Parrot Snake (Bothriopsis bilineata), also known as vibora loro, cobra papagaio and two-striped forest pit viper. This snake is slender and green and is an arboreal species with a prehensile tail.

Guyanese Parrot Snake

Bothriopsis bilineatus

The best-known representative of the genus Bothrops (the lance heads) in Guyana is the Labarria (Bothrops atrox), also known as the jararaca in Brazil, equis, and jergon in Ecuador and Peru. This snake is a thick bodied lowland rain forest species often found near waterways, and is very common in agricultural and urban areas. The labarria is notorious for biting humans. This is in part because of its propensity to live near humans. The labarria is therefore one of the most important venomous snakes in Guyana.

Labarria

Bothrops atrox

There is only one member of the genus Crotalus in Guyana - Crotalus durissus known locally as the Rattlesnake. This snake's English name is the "neotropical rattlesnake," but it is known as the cascabel in Spanish and boicininga in Portuguese. This species can be found from Mexico to Uruguay. It is usually found in dry habitats and is common in the Rupununi savannahs in Guyana. The rattlesnake has a fat body and may reach 1,500 mm in length. Older and larger adults of this species have a very distinctive dorsal ridge. The most distinctive feature of this snake is the rattle on the tail - modified scales used as a warning, and perhaps as a lure for prey. This species is also important because of the numbers of snake-bites attributed to it. The venom of this snake contains toxins that act both on tissues and the nervous system. The neotropical rattlesnake is therefore unusual as a viper because its venom also contains neurotoxins.

Rattlesnake

Crotalus durissus

Elapids

These are fixed-fang venomous snakes. Each fang has a hollow passage along the length of the whole tooth. The fangs are permanently erect and fit into grooves in the floor of the mouth. They are usually diurnal and have slender bodies. There are six recorded species of Elapids in Guyana - all in the genus Micrurus.

Perhaps the most famous of the Guyanese coral snakes is the Himeralli (Micrurus surinamensis) which is the heaviest (800-1,000 mm) of the coral snakes. This snake is also known as the aquatic coral snake, the coral venenosa in Bolivia, and the boichumbeguacu in Brazil. It is found throughout the Amazon including the Guianas. This species is a very good swimmer, and spends much time in streams and rivers. The himeralli is tricolored with red, black and cream-yellow rings in a repeating pattern of red, black, cream, black, cream, black, red. The venom of all coral snakes is strongly neurotoxic, which means that respiratory paralysis may result leading to suffocation.

Himeralli

Micrurus surinamensis

Colubrids

Although there are some venomous snakes in the family Colubridae, Guyana's colubrids are generally non-venomous. Some colubrids inject venom through fixed-fangs set in the rear of the mouth. Colubrids are the most diverse family of snakes in the world and their prey may range from bird and frog eggs to snails and spiders.