10 Big Facts About Anacondas

A green anaconda, the queen of snakes
A green anaconda, the queen of snakes / Jenhung Huang/iStock via Getty Images

Most people know that green anacondas are huge. But you may not know that they give birth to live young and can stay underwater for up to 10 minutes on a single breath. Read on for more gripping facts about these massive snakes.

1. Anacondas are members of the boa family.

Anacondas belong to Boinae, the family of large, non-venomous snakes collectively called boas. There are four species of anaconda today: Green anacondas (Eunectes murinus), yellow anacondas (E. notaeus), Bolivian anaconda (E. beniensis), and the dark-spotted anaconda (E. deschauenseei). The biggest and best known are the green anacondas, which live live in wetlands and river basins through tropical South America, including parts of Brazil, Colombia, Venezuela, Guyana, Surinam, Bolivia, Peru, and Ecuador. Green anacondas may be on there way to becoming established as an invasive species in parts of southern Florida like its boa cousin, the Burmese python.

2. The green anaconda is the world’s heaviest snake, but not the longest.

Large anacondas often weigh more than 200 pounds, but the longest snake on Earth is the reticulated python (Python reticulatus). They average around 25 feet long.

3. Anacondas are ambush predators.

Like other boas, anacondas lack venom with which to neutralize their prey. Instead, the lie in wait for an unsuspecting mammal, fish, or amphibian to wander within reach. Then, they lunge, catch the prey in their jaws, and wind their incredibly muscular bodies around the animal until it suffocates or dies from being crushed.

4. Anacondas are not picky eaters.

Green anacondas will eat almost anything, including birds and their eggs, other reptiles and amphibians, fish, and mammals. They’ll even consume animals as large as peccaries (a type of wild pig), tapirs, deer, and sheep. Capybaras frequently weigh up to 140 pounds and constitute one of the snakes’ chief meals.

5. Green anacondas won’t say no to snacking on other big reptiles.

Caimans are alligator-like aquatic reptiles native to South American rivers. The numerous species of caiman range in length from about 5 feet to 13 feet, making them formidable prey for anacondas. Despite their enormous size and strength, anacondas often sustain significant injuries while hunting caimans.

6. Like most snakes, anacondas have four rows of teeth on their upper jaws.

Four parallel lines of backwards-pointing teeth help serpents grasp their prey and swallow it whole. The lower jaw adds another two rows for extra grip.

7. Male and female anacondas show the biggest size difference on Earth.

The difference in appearance between males and females of the same species is called sexual dimorphism. Green anacondas demonstrate the biggest size gap among terrestrial vertebrates: While males can reach an average length of about 10 feet, females can grow to be more than 17 feet and perhaps up to 25 feet long.

8. Anacondas give birth to live young.

Several types of snakes, including anacondas and garter snakes, are ovoviviparous. Essentially, their offspring emerge from eggs inside their mothers’ bodies, then are born live. A healthy female anaconda mom can bear more than 30 babies per litter.

9. Anacondas can remain submerged for up to 10 minutes at a time.

In addition to their breath-holding ability, anacondas, like crocodiles, have eyes and nostrils on the tops of their heads so that they poke above a river’s surface while the rest of the snake is still underwater. No wonder the stealthy, semi-aquatic predators are occasionally called “water boas.”

10. Anacondas may or may not eat people.

There’s no doubt that a green anaconda could kill and eat a human. They do consume white-tailed deer—which can weigh over 120 pounds, about the mass of a slender adult person—in the wild. But as of now, there are no verified reports of any anaconda ingesting people.