A dolphin is a mammal and not a fish.
This is because it has characteristics of a mammal.
Physical Appearance: Dolphins range in color from light gray to dark gray on their backs, which lightens to white on their underbellies and beneath their jaws.
Social Behavior : Dolphins form strong bonds with other dolphins, and if one dolphin become injured, the others help it to reach the surface.
A dolphin is a mammal.
A dolphin is a mammal.
MAMMAL
a dolphin is a mammal
Because it is. There's not really a "why". If you mean "what are the characteristics of a dolphin that show that it's a mammal and not a fish or amphibian", it's warm-blooded, produces milk, and gives birth to live young.
A dolphin is a (marine) mammal. I could see why you may have thought amphibian, however an amphibian is more of a frog/lizard species.
A dolphin is neither reptile, amphibian, or fish. It is a mammal. It comes up to the surface of the water to breathe air through it's blowhole.
Dolphins are classifiedas mammals. They give birth to live young.
A dolphin is a mammal.
A "dolphin" is a mammal.
Shark is to fish dolphin is to mammal.
Newt is an amphibian