Whales, along with dolphins and porpoises, are warm-blooded mammals and breathe air like humans do.
There are some significant differences between whales and fish:
Whales are warm blooded. Fish are cold blooded.
Whales breathe air through lungs. Fish use gills to extract air from water.
Whales give birth to live young. Most fish (with some exceptions) lay eggs.
The tail of a whale moves up and down. The tail of a fish moves from side to side.
Other marine mammals include seals, fur seals, sealions, dugongs, manatees, walruses, sea otters and even polar bears!
What is a whale shark?
A whale shark is a fish. It is the largest member of the shark family. Like many large whales it feeds on tiny creatures in the ocean such as plankton.