Jararacussu
Bothrops jararacussu
One of the largest South American lanceheads, a heavy-bodied forest pit viper capable of delivering large venom yields.
- Venomous?
- Venomous
- Adult length
- 1.5-2.2 m (5-7.2 ft)
- Range
- Southeastern and southern Brazil, Paraguay, northern Argentina
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Overview
The Jararacussu is among the largest members of the lancehead genus, inhabiting forested regions of southeastern and southern Brazil and neighboring countries. Its considerable size and venom yield make it one of the more medically significant pit vipers in South America.
Adults are typically dark, sometimes nearly black, with faded or obscure blotching, while juveniles show a more distinct pattern of dark diamond-shaped markings on a yellowish-brown background.
How to identify it
- Heavy-bodied, large pit viper, among the biggest lanceheads
- Adults often dark brown to nearly black with indistinct pattern
- Juveniles show clearer dark diamond blotches on a paler background
- Broad, triangular head distinct from the neck
- Vertical pupils and heat-sensing pits
Habitat & range
Found in Atlantic Forest and other humid forest habitats of southeastern and southern Brazil, extending into Paraguay and northern Argentina. Often associated with dense, moist forest with heavy leaf litter.
Behavior, diet & reproduction
Primarily nocturnal, ambushing rodents and other small vertebrates from forest floor cover. Can be defensive when disturbed given its large size and venom yield. Live-bearing, producing sizable litters.
Frequently asked questions
How large does the Jararacussu get?
It is one of the largest lanceheads, reaching over 2 m (7 ft) in exceptional individuals.
Is it more dangerous than other lanceheads?
Its large size allows for greater venom yield, making bites potentially more serious, though all Bothrops species warrant caution.
Where does it live?
Atlantic Forest and other humid forests of southeastern and southern Brazil, Paraguay, and northern Argentina.
How does its appearance change with age?
Juveniles have clearer diamond-shaped blotches that often fade to a darker, less distinct pattern in adulthood.
Jararacussu guides
In-depth guides for identifying and understanding Jararacussu.
