Sharks vs. Dolphins: Blood Battle

They've shared the ocean for thousands of years, but scientists have only begun to understand the relationship between SHARKS and DOLPHINS. New research allows us to peer into this incredible drama; redefining everything we thought we knew about sharks. They're stereotyped as independent loners, serial killers of the sea-but we've observed them hunting in teams, learning, and even passing on knowledge to fellow sharks.—National Geographic Wild