Nature: Sharks

ShareThisTwo episodes from the PBS series "Nature" attempt to explain the mysterious ways of one of the ocean's most feared predators. "The Secret World of Sharks and Rays" takes a close look at sharks and their cousins, the rays -- two misunderstood creatures. "White Shark/Red Triangle" introduces viewers to an area between San Francisco and Monterey, Calif., known as the Red Triangle, where late summer sees an abundance of marine mammal activity.