# Green Anaconda (*Eunectes murinus*)

> The green anaconda (Eunectes murinus) is the heaviest snake in the world, a giant non-venomous constrictor of South America's swamps and slow rivers. It grows up to around 5 m long, sometimes longer, and can weigh 70 kg or more. Spending much of its life in water, it hunts by ambush, coiling around prey and suffocating it. Wild green anacondas live around 10 years and are listed as Least Concern.

- **Category:** Reptile
- **Conservation status (IUCN):** Least Concern
- **Range:** Swamps, marshes, and slow rivers of the Amazon and Orinoco basins in tropical South America.
- **Canonical page:** https://globalanimalguide.org/animals/green-anaconda/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Reptilia
- **Order:** Squamata
- **Family:** Boidae
- **Genus:** Eunectes

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Eunectes murinus |
| Diet | Carnivore |
| Habitat | Swamps, marshes, and slow tropical rivers |
| Lifespan | About 10 years in the wild |
| Length | Up to 5 m (16 ft), sometimes longer |
| Weight | Up to 70 kg (150 lb) or more |
| Conservation status | Least Concern (IUCN) |

## The world's heaviest snake

While the reticulated python can grow longer, the green anaconda is the heaviest and bulkiest snake on Earth, with large individuals reaching about 5 m and weighing 70 kg or more. Its body is thick and muscular, olive-green with black oval blotches that provide camouflage in murky water and among vegetation. Females are considerably larger than males, a pattern common among constricting snakes. The eyes and nostrils sit high on the head, letting the snake lie almost fully submerged while watching for prey.

## A life in the water

Green anacondas are semi-aquatic and spend most of their lives in and around water, favouring swamps, marshes and slow-moving tropical rivers in the Amazon and Orinoco basins. Their heavy bodies are supported by water, allowing them to move with surprising ease when submerged even though they are slow and cumbersome on land. On the ground they slither at only a few kilometres per hour, but in water they swim smoothly and can stay under for many minutes. This aquatic habit gives them both cover for ambush and relief from their own great weight.

## Hunting and diet

The green anaconda is a carnivore and an ambush predator, lying still in shallow water until an animal comes to drink or wade past. It seizes prey with its backward-curving teeth, throws coils around the victim and constricts, tightening with each breath the animal takes until it can no longer breathe. It then swallows the prey whole, head first. Its diet includes capybaras, caimans, deer, fish, turtles and birds, and a large meal can sustain the snake for weeks or months before it needs to feed again.

## Reproduction

Green anacondas give birth to live young rather than laying eggs, with the developing embryos nourished inside the mother. During the breeding season several males may gather around a single large female, forming a slow-moving mass sometimes called a breeding ball as they compete to mate. After a gestation of around six to seven months, the female produces a litter that can range from a handful to several dozen young snakes. The newborns are already around 60 cm to a metre long and are independent from birth.

## Anacondas and people

Anacondas feature heavily in legend and film, where they are often shown as monsters that hunt humans, but attacks on people are extremely rare. A wild anaconda is far more likely to slip away into the water than to confront a person. They are not venomous and pose little threat away from careless handling. Listed as Least Concern, the green anaconda remains widespread across tropical South America, though habitat loss and hunting for skins are local pressures.

## Frequently asked questions

### Is the green anaconda the biggest snake in the world?

It is the heaviest and bulkiest snake in the world, reaching around 5 m and weighing 70 kg or more. The reticulated python can grow longer, but no snake is as massive as the green anaconda.

### How does an anaconda kill its prey?

The green anaconda is a constrictor, not a venomous snake. It ambushes prey, coils around it and squeezes, tightening each time the animal exhales until it can no longer breathe. It then swallows the prey whole, head first.

### What do green anacondas eat?

They are carnivores that eat capybaras, caimans, deer, fish, turtles and birds. As ambush hunters they wait in shallow water for prey to come near. A single large meal can sustain the snake for weeks or even months.

### Do green anacondas attack humans?

Attacks on people are extremely rare. A wild anaconda will almost always retreat into the water rather than confront a person. Their fearsome reputation comes mostly from films and legend rather than real behaviour.

### How long do green anacondas live?

In the wild, green anacondas live around 10 years. They can live longer in captivity with consistent food and care, where some reach their late teens or beyond.

### Where do green anacondas live?

They live in the swamps, marshes and slow-moving rivers of tropical South America, mainly in the Amazon and Orinoco basins. Being semi-aquatic, they spend most of their time in or near water, which supports their heavy bodies.

## Sources

- Anaconda assessments. IUCN Red List of Threatened Species.
- The Reptile Database (reptile-database.org).
- [Animal Diversity Web — Eunectes murinus. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Eunectes_murinus/)

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Source: Global Animal Guide (https://globalanimalguide.org/animals/green-anaconda/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.