Bothrops atrox or Bothrops lanceolatus
The Fer-de-lance (also known as Lancehead) are several closely related species in this group. All are very considered to be very aggressive and dangerous to man and one of the most feared snakes on the planet.
Description: Lancehead or Fer-de-lance snakes have highly variable coloration, from gray to olive, brown, or reddish, tan, or nearly black with dark triangles edged with light scales. Triangles are narrow at the top and wide at the bottom and are usually clearly marked (but may be blotched). Some have a yellow zig-zag line on each side of the body.
The bottom side is of the snake’s body may be yellow, cream, or light gray. They typically grow 2 1/2 feet to 5 feet in length.and have moderately heavy bodies. The broad, flattened head typically does not have markings. Female Fer-de-lance may grow much larger than males and have heads and fangs up to three times larger than the male of the species.
Characteristics: This highly dangerous snake is responsible for a high mortality rate. It has an irritable disposition, ready to strike with little provocation. The female fer-de-lance is highly prolific, producing up to 60 young, all with a dangerous bite. The venom of this species is hemotoxic, painful, and hemorrhagic (causing profuse internal bleeding). The venom causes massive tissue destruction.
They are aggressive and strike very quickly (they are known in the area as the “ultimate pit viper”). Even one that is quickly retreating from a threat may suddenly reverse direction and strike. They have been known to eject venom from their fangs at a distance of more than six feet.
Symptom: They are common in coffee and banana farms where workers are frequently bit by snakes in hiding. They are greatly feared because of the potential for massive tissue damage (even with treatment).
The venom is lethal and fast acting and can cause massive tissue damage. Victims may experience extreme pain and oozing wounds, nausea, blackouts, and paralysis. Temporary of permanent lost of short term memory is common. Bruising may begin at the bite area and spread. Swelling can be so severe that skin must be cut away to release the pressure. Blistering, numbness, fever, headache, bleeding from mouth and gums, internal bleeding, and necrosis of the limb all occur.
Treatment: Victim can survive if treated quickly but they are responsible for a large number of deaths. Once treatment begins, extended hospital stays are typically required. Weight loss after a bite is common too. Follow normal snake bite treatment but medical attention is required quickly.
Habitat: Found on cultivated land and farms, often entering houses in search of rodents, frogs, lizards, and small birds. They prefer wet to moist lowland forests but with declining areas, they move into residential areas in search of food. Their proximity to human habitations is one of the reasons this snake is so commonly feared. They are excellent tree climbers and well seasoned swimmers too.
Length: Average 1.4 meters (5 feet), maximum 2.4 meters (8 feet).
Distribution: Southern Mexico, throughout Central and South America.
In the photo below, the 11-year old boy was bit by a fer-den-lance snake on the back of the leg causing massive tissue damage (necrosis). He did not receive adequate treatment (he was originally treated with antibiotics only) quickly enough and was soon hospitalized.