Dolphins vary from fish in a number of ways. Both dolphins and fish have adapted to live their whole lives in the water, both have streamlined bodies and fins. But, dolphins are mammals and so they need regularly visit the surface to breathe air to survive, otherwise they would drown. Fish on the other hand extract oxygen from the water and do not need to surface.
Dolphins evolved from land mammals whose legs were underneath their bodies. As a result, dolphins tails move up and down as they swim, whereas a fish’s tail moves from side to side.
Dolphins are warm-blooded and have blubber to keep them warm. Fish are cold-blooded and are able to adjust to the different temperatures of the water without the need of body fat to keep them warm.
Most species of fish are also known to lay eggs and can lay hundreds of eggs in a single year. Dolphins give birth to a single baby once every 1 – 6 years and then feed their babies milk through their nipples.
Amazing facts about whales and dolphins
Dive deeper into the world of whales and dolphins and learn more about their lives.
Facts about whales
Amazing facts about whales, the largest mammals to live on Earth.
Facts about dolphins
From the orca to the tiny vaquita, learn more about these creatures.
Record breakers
Whales and dolphins hold some incredible records.
Brain power
Just how intelligent are whales and dolphins?
Help protect whales and dolphins and their homes
By adopting a whale or dolphin, by making a donation, or by fundraising for WDC, you can help us save these amazing creatures.
Adopt
Adopt an orca and help us protect these amazing creatures.
Donate
Your gifts help us take action to protect their homes.
Fundraise
Run, bake, walk, cycle… what could you do for orcas?