From the Book Jacket:
It spends its life swimming in the ocean, but it is not a fish.
Intelligent and playful, it leaps through the water like a torpedo.
It can "see" with its eyes closed.
Who is this prince of the waves?
It is our friend the dolphin.
In the same series:
The Cheetah, Fast as Lightning
The Penguin, A Funny Bird
The Elephant, Peaceful Giant
The Seal, Furry Swimmer
The Deer, Forest Friend
The Bee, Friend of the Flowers
The Giraffe, A Living Tower
The Polar Bear, Master of the Ice
The Hippopotamus, River Horse
The Fox, Playful Prowler
The Whale, Giant of the Ocean
The Wolf, Night Howler
The Frog, Natural Acrobat
The Sea Lion, Ocean Diver
The Brown Bear, Giant of the Mountains
The Shark, Silent Hunter