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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

Anacondas are four species of aquatic boa inhabiting the swamps and rivers of the dense forests of tropical South America (especially in the Amazon and Orinco basins). The Green Anaconda snake is the most popular and the largest member of the boa family of snakes and the largest snake in the world. Female anacondas are significantly larger than males and they have the largest sexual dimorphism of all the snakes. It has a girth of nearly 30 cm (12 in.) and a weight of 227 kg (550 lb.), making it the heaviest of all snakes. Their enormous size makes it much easier for green anacondas to swim in the water than to slither slowly on land. Their eyes and nostrils are on the top of their head allowing them to see and breathe while most of their body is under water. This way they can be stealth and sleek in water and lay in wait for prey while remaining nearly completely submerged.

South American Green Anaconda (Eunectes murinus)

Other anaconda species, include the yellow, dark-spotted, and Bolivian varieties. They are all from South America and all smaller than the green anaconda.


They feed on wild pigs, deer, birds, turtles, capybara, caimans, and even jaguars.

Anacondas are not venomous but they kill their prey by grabbing the animal in its jaws, locking it in with its teeth, coiling their muscular bodies around their captured prey and squeezing until the animal dies of crushing or suffocation.


The Anaconda can swallow prey whole even if its much bigger than the size of its mouth because its jaws bones have stretchy ligaments, are loosely connected to the skull and can unhinge. While the snake eats, its muscles have wave-like contractions, crushing the prey even further and surging it downward with each bite. They can go weeks or months without food after a big meal. Most of their time is spent in the water hunting. Although they use both sight and smell to hunt, they also have the ability to sense heat emitted by potential prey.

Green anacondas also partake in cannibalism as the females, the larger of the sexes, have been reported to eat smaller male anacondas.


Between April and May, the males seek out females for the opportunity to mate. Often times, multiple males will pursue the same female. This usually results in “breeding balls” of up to a dozen males wrapped around a single female, all attempting to mate. The breeding ball can last up to 4 weeks.


Once pregnant, the female will produce and retain eggs inside her body. The eggs develop for 8-12 weeks and then hatch while still inside the mother’s body. She then gives birth to as many as multiple dozens of live young anacondas. Baby snakes are about 2 feet (0.6 meters) long when they are born and are almost immediately able to swim and hunt.


The Anaconda is most active at night which makes it a nocturnal reptile. Although they are not venomous, they defend themselves by inflicting severe bites, or kill its attacker/prey by constriction. It is possible to be bitten by an Anaconda, but the bite itself would not be fatal. Most local people kill these snakes on sight, out of the fear that they are man-eaters. In most instances, if an Anaconda senses humans in the area, it will retreat in another direction.


Conservation Status

Anacondas are sometimes hunted illegally for their skin or to be sold as pets. However, their size makes them inconvenient pets, and their skin is not very popular for clothing and shoes. They are also very difficult to catch. They also face the threat of habitat destruction but despite this, they are not considered endangered.

Adapted from National Geographic, Animal Fact Guide and Animal Corner



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