The anacondas, also known as anacondas, arigboias, boiaçus, boiçus, boiguaçus, boioçus, boitiapoias, boiuçus, boiunas, anacondas, sucurijubas, anacondas, sucurujus, sucurujubas or viborões, is a genus of boinae found in South America.
They are a semiaquatic group of snakes and include one of the largest snakes in the world, Eunectes murinus, the green anaconda.
The name Eunectes is derived from the Greek word Eυνήκτης, meaning "good swimmer".
Four species are currently recognized.
There are four species, of which the first three occur in Brazil: Eunectes notaeus, the yellow anaconda, endemic to the Pantanal area; Eunectes murinus, the green anaconda, the largest and best known, occurring in flooded areas of the Cerrado and Amazon region, and in the latter biome, the animals tend to reach larger sizes; Eunectes deschauenseei, the spotted anaconda, occurs on Marajó Island and French Guiana, as well as in some other parts of Amazonia; Eunectes beniensis, the Bolivian anaconda.