View full lesson: http://ed.ted.com/lessons/eli-the-eel-a-mysterious-migration-james-prosek

They're slippery. They're slithery. And while they totally look like underwater snakes, eels are, in fact, unique fish that can breathe through their skin and even survive out of water. James Prosek tracks the life journey of Eli the Anguilla eel as she (yes, she) travels her mysterious "backward" migration from the sea to fresh water and back again.

Lesson by James Prosek, animation by Cinematic.