The green anaconda, common anaconda, common water boa, akayima, or sucuri, is a boa species found in South America. It is one of the longest and heaviest known extant snake species. Like all boas, it is a non-venomous constrictor. The green anaconda (Eunectes murinus), common anaconda, common water boa, akayima, or sucuri, is a boa species found in South America. It is one of the longest and heaviest known extant snake species. Like all boas, it is a non-venomous constrictor. Green anacondas only have a lifespan of 10 years in the wild, although some specimens live longer when they are taken care of in captivity. Green anacondas live in tropical rainforests and tend to prefer shallow, slow-moving waters, such as streams, rivers and flooded grasslands. They spend most of their time in the water but are also found on land in thick vegetation. In the famous 10th edition of Systema Naturae of 1758, Carl Linnaeus cited descriptions by Albertus Seba and by Laurens Theodorus Gronovius to erect the distinct species murina of his new genus Boa, which contained eight other species, including Boa constrictor. Many of green anacondas’ physical characteristics provide camouflage while hunting prey. The snakes draw their name from the olive color of their body, and the spine is lined with dark circles. Green anacondas possess yellow and black scales along the belly, and a second set of black circles with yellow centers are scattered along the sides. Two dark stripes can be found on the head from the eyes to the jaws, providing further camouflage. Green anacondas’ eyes and nasal slits are positioned at the top of the head, allowing the snakes to lie almost fully concealed underwater in wait for prey.
Green anacondas are known for their immense size, claiming the title of the world’s largest snakes by weight and girth. While their average length is about 5.5 meters (18 feet), green anacondas can grow as long as 9 meters (30 feet). The reticulated python is longer; however, green anacondas weigh much more because of their immense girth, about 30 cm (1 foot) in diameter. Green anacondas can thus weigh as much as 250 kg (550 pounds), almost twice as heavy as the reticulated python. Green anacondas display sexual dimorphism, females being significantly larger than males. Because of their large size, green anacondas are often the subject of urban legends related to the discovery of very large specimens. The Hollywood film Anaconda (1997) and its sequels featured green anaconda specimens longer than 10 meters (30 feet), but such sizes have not been scientifically verified. For many years, green anacondas were considered to be a single species, E. murinus. In 2024 researchers discovered that there are two genetically distinct species: the original green anaconda (E. murinus), to be called the southern green anaconda, and the northern green anaconda (E. akayima). The two species are morphologically similar, and doubts have been raised over the validity of the DNA studies that identified the two species as separate.
