Anacondas are large, nonvenomous boas of the genus Eunectes. They are found in tropical South America.
The most familiar species is the green anaconda, Eunectes murinus, notable for being one of the world's largest snakes. Green anacondas can grow to more than 5.21 m (17 ft) in length and weighing 97.5 kg (215 lb). They are found east of the Andes in Colombia, Venezuela, the Guianas, Ecuador, Peru, Bolivia, Brazil, and on the island of Trinidad.
Other anacondas are the yellow anaconda, Eunectes notaeus, a smaller species found in eastern Bolivia, southern Brazil, Paraguay and northeastern Argentina, the dark-spotted anaconda, Eunectes deschauenseei, a rare species found in northeastern Brazil, coastal French Guiana and Guyana; and the Bolivian anaconda, Eunectes beniensis, discovered in 2002 in the flood plains of Bolivia's Pando province. It was the first new anaconda species identified since 1936, and became only the fourth known type of that reptile, according to the WWF.
All four species are aquatic snakes that prey on other aquatic animals, including fish, river fowl, caiman, and capybaras. Some accounts exist of anacondas preying on domestic animals such as goats and ponies that venture too close to the water.
While encounters between people and anacondas may be dangerous, they do not regularly hunt humans. Nevertheless, threat from anacondas is a familiar trope in comics, movies and adventure stories set in the Amazon jungle. Anacondas have also figured prominently in South American folklore, where they are sometimes depicted as shapeshifting mythical creatures called encantados. Local communities and some European explorers have given accounts of giant anacondas, legendary snakes of much greater proportion than any confirmed specimen.Applied loosely, the term "anaconda" may also refer to any large snake that "crushes" its prey by constricting.