The green anaconda is one of the world’s largest snakes. The reticulated python of Southeast Asia attains tremendous lengths, but they are not nearly as heavy bodied as large female green anacondas. A 20-foot-long female green anaconda may weigh well over 200 pounds. These snakes are semi-aquatic, spending a great deal of time submerged in floating vegetation such as water lettuce and water hyacinths.
These large constrictors are in the boa family and like all boas produce live young. Baby anacondas are almost three feet long, and their coloration is very similar to the adult coloration — dark green to almost olive background coloration with large black and yellow circular markings on the sides that alternate with dark blotches on the back.
Once reaching adult size, anacondas are basically apex predators but occasionally jaguars and large black caiman may be successful in killing a fairly large snake. Of course, jaguars and caiman may also find that they have taken on something a little bigger than they should have and in turn become prey for big snakes. Anacondas are basically ambush predators, feeding on a variety of creatures including birds, mammals, reptiles and fish. Anacondas have tremendously long teeth that allow for deep penetration through fur or feathers. They, like most snakes, have four rows of teeth on the top jaw. Two independent rows on the top side of each top jaw and two rows down the palate of the mouth. There are also two independent rows of teeth on the lower jaws. The lower jaws are not connected which allow snakes to use their jaws, alternating each one to help pull their prey into their mouths for swallowing.
Anacondas are not usually dangerous snakes as they do not consider man as prey, but problems occur when people try to catch large specimens. Once cornered, an anaconda becomes a very tenacious adversary and they can strike fairly long distances. A bite from a large anaconda can be very serious as the teeth are large and terrible lacerations often result from a bite. The biggest problem is secondary infection. So leave anacondas unmolested, simply marveling at the physical attributes and amazingly cryptic coloration if you encounter them in the wild should be sufficient.
Like many predators, man is the reason for declines of this species in many areas. If an anaconda is restrained in a village that you visit during your Amazon cruise with International Expeditions , please do not pay the locals to have your picture taken with the snake. This only encourages them to collect more for the purpose of financial gain at the exploit of a magnificent and important species of the Amazon.
Watch a video of our naturalist guides capturing a female anaconda along the banks of the Amazon  shot by one of our Amazon cruise guests.
Naturalist Greg Greer  is a favorite among IE travelers, and has gained a reputation for his friendliness and good humor, along with his incomparable knowledge of natural history, photos and articles have been widely published in books and magazines, including Georgia Outdoor News, Bird Watcher’s Digest, Alabama Outdoor News, Riversedge and Southern Wildlife.