Green Anaconda

Lore & Background

The species was first described by Carl Linnaeus in the 10th edition of Systema Naturae (1758) as Boa murina. The generic name Boa came from an ancient Latin word for a type of large snake. In 1830, Johann Georg Wagler erected the separate genus Eunectes for Linnaeus's Boa murina. The specific name murina was changed to murinus due to the masculine gender of Eunectes. Linnaeus chose the name based on Albertus Seba's 1735 description, with murina meaning 'of mice' or 'preying on mice', not 'mouse-gray-colored'. Early English sources referred to it as the 'rat boa'. The local Carib people have used the name akayima for centuries, meaning 'The Great Snake'.

In Their Own Story

The green anaconda is the world's heaviest and one of the world's longest snakes, reaching a length of up to 6.32 m (20 ft 9 in) long. More typical mature female specimens reportedly can range up to 5 m (16 ft 5 in), with a mean length of about 4.6 m (15 ft 1 in), being generally much larger than males, which average around 3 m (9 ft 10 in). Weights are less well studied, though reportedly range from 30 to 80 kg (66 to 176 lb) in a typical adult. It is the largest snake native to the Americas. Although it is slightly shorter than the reticulated python, it is far bulkier. The bulk of a 5.2-metre (17 ft 1 in) green anaconda is comparable to that of a 7.4-metre (24 ft 3 in) reticulated python. The longest and heaviest verified specimen encountered by Jesús Antonio Rivas, who had examined more than 1,000 anacondas, was a female 5.21 m (17 ft 1 in) long and weighing 97.5 kg (214 lb 15 oz). In 1937, a specimen shot in Guyana was claimed to have measured 5.9 m (19 ft 4 in) long and weighed 163 kg (359 lb 6 oz). The color pattern consists of an olive green background overlaid with black blotches along the length of the body. The head is narrow compared to the body, usually with distinctive orange-yellow striping on either side. The eyes are set high on the head, allowing the snake to see out of the water while swimming without exposing its body. The anaconda's jaw bones splay open at the front because they are loosely connected by flexible ligaments instead of bone. This allows it to swallow prey larger than the size of its head. The windpipe in its mouth allows it to breathe while swallowing its prey. Its largest internal organ is the liver. The digestion process takes many days to complete. During this time, the anaconda behaves very sluggishly.

Reader's Guide

The green anaconda is the world's heaviest and one of the world's longest snakes, reaching a length of up to 6.32 m (20 ft 9 in). Typical mature females range up to 5 m (16 ft 5 in), with a mean length of about 4.6 m (15 ft 1 in), and are generally much larger than males, which average around 3 m (9 ft 10 in). Weights reportedly range from 30 to 80 kg (66 to 176 lb) in a typical adult. The color pattern consists of an olive green background overlaid with black blotches. The head is narrow compared to the body, usually with distinctive orange-yellow striping on either side. The eyes are set high on the head. The jaw bones splay open at the front, allowing it to swallow prey larger than its head. The windpipe allows it to breathe while swallowing. Its largest internal organ is the liver. Digestion takes many days, during which the snake behaves very sluggishly.

Did You Know?

• The green anaconda is the largest snake native to the Americas.
• Although slightly shorter than the reticulated python, it is far bulkier.
• The longest and heaviest verified specimen examined by Jesús Antonio Rivas was a female 5.21 m (17 ft 1 in) long and weighing 97.5 kg (214 lb 15 oz).
• Reports of anacondas 11–12 m (35–40 ft) or longer exist, but no specimens of such lengths have ever been deposited in a museum.
• The skin of one specimen, stretched to 10 m (32 ft 10 in), is preserved in the Instituto Butantan in São Paulo, reported to have come from an anaconda of 7.6 m (24 ft 11 in).