NARRATOR: This intimidating reptile is the heaviest snake in the world, and one of the largest. At 30 feet, the anaconda can grow to be nearly the length of a school bus. When most people say anaconda, they're referring to the largest of the four species of anacondas, the green anaconda.
At up to 550 pounds, that's some serious heft. But these massive snakes have another lesser-known characteristic. They thrive in water.
In fact, the name of the anaconda's genus is Eunectes, meaning good swimmer. Eyes and nostrils positioned on top of their heads allow the snakes to remain almost completely submerged as they wait to ambush prey. Anacondas aren't venomous snakes.
They are constrictors. In seconds, anacondas wrap around their prey, constricting tighter and tighter until the blood supply is cut off. Like other constrictors, anacondas sense when their prey's heart has stopped, and only then release their grip and begin to eat their meal whole.
Anacondas swallow their prey whole with the help of both stretchy ligaments and mobile joints in their mouths. In the middle of the anaconda's upper jaw are two rows of backward-pointing teeth. These teeth can move independently, biting into prey, and helping move the snake's head up and over its meal.
But eating a meal in this way creates a unique problem. With its mouth stretched so tightly around the animal, the anaconda can't breathe as it normally would. But through evolution, the snake has developed a clever trick to deal with that.
The windpipe, normally located deep in the throat, gets pushed up and out of the mouth, acting like a snorkel and allowing the anaconda to breathe. And breathing normally is especially important, given the time it takes an Anaconda to finish its meal. A green anaconda can take many hours to swallow a meal, and more than a week to digest it.
Large prey such as capybara and even jaguar provide the anacondas the energy they need to maintain their size. Once consumed, the Anaconda will not need to eat again for weeks or months. And when 30% of the female's body weight is used for reproduction, their prey are also vital to the female anaconda's survival.
Unlike most of the world's snakes, anacondas don't lay eggs. Instead, the young hatch while still inside of their mother, who will later give live birth. After seven months of fasting during pregnancy, the anaconda mom takes in some of the nutrients she lost by feasting on her eggs that never developed, and any of her young which were not born alive.
With an average of 20 to 40 babies per brood, it could be hard to keep them all in line. For the anaconda, however, this isn't a problem. Immediately after being born, the anaconda babies are able to make it on their own without the help of mom.
Born with the instincts to hunt and fend for themselves, baby anacondas have the innate skills to survive and become the next giants of South America's Amazonian waterways and jungles.
