Whales have sleek, streamlined bodies that move easily through the water. Whales breathe air. They are NOT fish. They are mammals that spend their entire lives in the water.
Cetaceans are the group of mammals that includes the whales, dolphins, and porpoises.
These enormous animals eat about 4 tons of tiny krill each day, obtained by filter feeding through baleen. Adult blue whales have no predators except man. The blue whale is the largest animal that has ever existed on Earth. It is larger than any of the dinosaurs were. They are also the loudest animal on Earth.