Next time you are at the zoo, talking to a science teacher or otherwise in a situation where you need some random animal information, here's some talking points from tonight's Wild: Amazon's Deadly Dozen episode.

The Anaconda is the heaviest snake, but it may or may not be the longest. The Reticulated python rivals the Anaconda for the longest snake. A 20-foot Anaconda will weigh more than a 33-foot python. The Anaconda can weigh 550 pounds or more, but will usually top out at a few hundred pounds. These snakes can measure more than 12 inches in diameter. The female typically outweighs the males.

Crocodilians in general are the most vocal of the reptiles, and Black Caimans emit vocalizations that sound like rumbling thunder to communicate with other caimans.

Bull Sharks ability to tolerate freshwater is rooted in salt retention. Sharks must retain salt inside their bodies. Without it, their cells will rupture and cause bloating and death. Given this requirement, most sharks cannot enter fresh water, because their internal salt levels would become diluted. But bull sharks have special physiological adaptations that enable them to live in fresh water. Their kidneys recycle the salt within their bodies and special glands, located near their tails, also aid in salt retention.