Fangtastic Facts
Jararaca
(Bothrops jararaca)
The Brazilian pit viper (Bothrops jararaca), also known as the jararaca, belongs to a group of snakes known as lanceheads. This mostly nocturnal species is active most of the year and responsible for most of the annual snake bites in Brazil.
Description
Bothrops jararaca typically has a brown, grey, olive, or tan background colour with dark trapezoidal or triangular flank markings edged in pale tones. A distinct dark stripe runs behind the eye, and the snout and upper lip scales are usually pale. The underside is yellowish or whitish with scattered grey blotches. Its body is often long, with keeled scales and the markings are more pronounced in juveniles. This variable, cryptic pattern provides excellent camouflage in forest leaf litter and vegetation.
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It shares the same triangular head and pointed snout as several other lanceheads of the same region. Colouration also varies between individual snakes of this species, making identification challenging.
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It has large venom glands behind its eyes, which give the head a triangular appearance. Its eyes have vertical pupils, and a heat pit is located on each side of its snout, which it uses to locate warm-blooded prey.
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Adults average 1.5 metres in length, with females growing larger and heavier than males.
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Important: Colour, markings and overall appearance can vary considerably between individual snakes. Photographs, descriptions and information on this website should not be relied upon to identify a potentially venomous snake. If you encounter a snake, keep your distance and leave identification and removal to trained professionals.
Distribution
The jararaca occurs in southern Brazil, northeastern Paraguay, and Argentina.
Habitat
It occupies diverse habitats, from tropical forests and savannas to subtropical upland forests. It often prefers open areas near forests, including agricultural land, grasslands, and clearings.
Diet
Jararacas use their heat pits to detect birds and small mammals, often at night. When it encounters a potential meal, it usually uses a strike-and-release method while it waits for its venom to take effect.
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Juveniles prey on frogs until they are old enough to take on a larger meal.
Behaviour
​Some researchers have reported observing caudal luring behaviour in juveniles. The young snake wriggles its brightly coloured tail tip to lure prey, often frogs, into believing it is a worm or similar food source. When the frog gets close enough, the snake can quickly bite and consume it.
Reproduction
This species is ovoviviparous, meaning the young hatch inside the mother and are born live. Usually up to 20 young are born; however, litters of up to 34 are known.
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Their reproductive cycle is influenced by the rainy season, with births normally occurring from the middle to the end of the rainy season.
Venom
Jararaca venom can interfere with blood clotting and damage blood vessels and surrounding tissues, contributing to bleeding, swelling, inflammation and tissue damage.
Predators
Birds of prey, king cobras and opossums may prey on jararaca’s, especially juveniles.
Humans also pose a threat to this species, as they are sometimes killed out of fear.
Conservation status
The IUCN Red List classifies the jararaca as a species of least concern.
Fangtastic Fact
Researchers developed the first ACE inhibitor, Captopril, by modelling it on a peptide found in jararaca venom. This breakthrough led to later drugs such as Enalapril and Lisinopril, which are widely used to treat high blood pressure. This is a powerful example of how snake venom research can save lives.
Disclaimer
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