Dolphins are classified as mammals, not fish. They belong to the infraorder Cetacea, which also includes whales and porpoises. Some key characteristics of dolphins that make them mammals include:
- They are warm-blooded, unlike fish, which are cold-blooded.
- They breathe air using lungs, not gills.
- They give birth to live young, rather than laying eggs.
- They feed their young with milk.
Dolphins are also known for their intelligence and social behavior.
