Dolphins and porpoises look very similar, but while these mammals share some features they aren't even in the same family. From tooth and jaw shape to the way t

"The Porpoise or Dolphin book in the Which Is Which? series helps readers discover the similarities and differences between porpoises and dolphins"--

An animal with smooth, gray skin jumps from the ocean waves. Its tail waves up and down before it quickly dives again. Did you just see a dolphin? Or was it a p

A guidebook to the many different species of whales, dolphins and porpoises that describes cetacean behavior and habitats.

The eighty-nine cetacean species that swim our seas and rivers are as diverse as they are intelligent and elusive, from the hundred-foot-long, two-hundred-ton b