Green Anaconda

Verified Timeline

Lore & Background

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. The generic name Boa came from an ancient Latin word for a type of large snake. The first specimens of Boa murina were of immature individuals from 75 to 90 cm (2.5 to 3.0 ft) in length. In 1830, Johann Georg Wagler erected the separate genus Eunectes for Linnaeus's Boa murina after more and larger specimens were known and described. Because of the masculine gender of Eunectes, the feminine Latin specific name murina was changed to murinus. Linnaeus almost certainly chose the scientific name Boa murina based on the original Latin description given by Albertus Seba in 1735: "Serpens testudinea americana, murium insidiator" [tortoise-patterned (spotted) American snake, a predator that lies in wait for mice (and rats)]. The Latin adjective murinus (murina) in this case would mean "of mice" or "connected with mice", understood in context as "preying on mice", and not as "mouse-gray-colored", another possible meaning of Latin murinus, as now often wrongly indicated for E. murinus. Common names for E. murinus include green anaconda, anaconda, common anaconda, and water boa. The word akayima and variants (okoyimo, okoimo) have been used by the local Carib people to refer to the green anaconda for centuries before its formal scientific description. The name akayima comes from the local Cariban languages, with akayi meaning "snake" and the suffix -ima describing largeness in a way that elevates the term to a separate category, giving a literal meaning of "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 lives in tropical rainforests and tends 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. The remote location of the snake's habitat has historically made locating, capturing, and returning specimens difficult. Transporting very large specimens to museums, especially before substantial decay, is difficult, though this has not prevented the return of much larger and more cumbersome crocodilian specimens. Skins can stretch substantially, increasing the snake's size by more than 50% if stretched during the tanning process. Reports without physical proof are considered dubious if from non-scientists, as such individuals may at worst be more interested in promoting themselves or telling a good tale, or at the least may not be sufficiently trained in proper measurement methods. Observational reports of animals that were not captured are even more dubious, as even trained scientists often substantially overestimate the size of anacondas prior to capture. According to the Guinness Book of World Records, this species has been perhaps subject to the most extreme size exaggerations of any living animal. The largest size verified for E. murinus in captivity was for a specimen kept in Pittsburgh Zoo and PPG Aquarium, which grew to a length of 6.27 m (20 ft 7 in) by the time she died on July 20, 1960. When this specimen was 5.94 m (19 ft 6 in) long, she weighed 91 kg (200 lb 10 oz).

Did You Know?

• The green anaconda is the world's heaviest snake, with a verified specimen weighing 97.5 kg (214 lb 15 oz) at 5.21 m (17 ft 1 in) long.
• The name 'akayima' comes from Cariban languages, with akayi meaning 'snake' and the suffix -ima describing largeness, giving a literal meaning of 'The Great Snake'.
• Linnaeus chose the scientific name Boa murina based on a Latin description meaning 'a predator that lies in wait for mice (and rats)', not 'mouse-gray-colored' as often wrongly indicated.
• The largest verified captive specimen was kept at Pittsburgh Zoo and PPG Aquarium, reaching 6.27 m (20 ft 7 in) before dying on July 20, 1960.
• 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).