Photo: A coiled anaconda

The largest snakes in the world, anacondas can grow to 550 pounds (227 kilograms).

Photograph by Ed George

Map

Map: Green anaconda range

Green Anaconda Range

Fast Facts

Type:
Reptile
Diet:
Carnivore
Average life span in the wild:
10 years
Size:
20 to 30 ft (6 to 9 m)
Weight:
Up to 550 lbs (227 kg)
Group name:
Bed or knot
Did you know?
In mating, several competing males form a breeding ball around one female that can last up to four weeks.
Size relative to a bus:
Illustration: Green anaconda compared with bus

A member of the boa family, South America’s green anaconda is, pound for pound, the largest snake in the world. Its cousin, the reticulated python, can reach slightly greater lengths, but the enormous girth of the anaconda makes it almost twice as heavy.

Green anacondas can grow to more than 29 feet (8.8 meters), weigh more than 550 pounds (227 kilograms), and measure more than 12 inches (30 centimeters) in diameter. Females are significantly larger than males. Other anaconda species, all from South America and all smaller than the green anaconda, are the yellow, dark-spotted, and Bolivian varieties.

Anacondas live in swamps, marshes, and slow-moving streams, mainly in the tropical rain forests of the Amazon and Orinoco basins. They are cumbersome on land, but stealthy and sleek in the water. Their eyes and nasal openings are on top of their heads, allowing them to lay in wait for prey while remaining nearly completely submerged.

They reach their monumental size on a diet of wild pigs, deer, birds, turtles, capybara, caimans, and even jaguars. Anacondas are nonvenomous constrictors, coiling their muscular bodies around captured prey and squeezing until the animal asphyxiates. Jaws attached by stretchy ligaments allow them to swallow their prey whole, no matter the size, and they can go weeks or months without food after a big meal.

Female anacondas retain their eggs and give birth to two to three dozen live young. Baby snakes are about 2 feet (0.6 meters) long when they are born and are almost immediately able to swim and hunt. Their lifespan in the wild is about ten years.

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