8. Dolphins are the only mammals that can swim upside down. This is because they have a special chamber in their inner ear that helps them to stay balanced.
7. Dolphins are marine mammals that have smooth skin, flippers, and a dorsal fin. They are highly intelligent and can display culture, use tools, recognize themselves in the mirror, and call each other by names.
6. Dolphins are not fish, but they breathe air and need to take regular trips to the surface of the water.
5. There are 36 dolphin species, found in every ocean.
4. The largest dolphin, the orca, can grow to be over 30 feet long. The smallest, the Maui dolphin, is just 5 feet long.
3. Dolphins feed chiefly on fish and squid, which they track using echolocation, a built-in sonar that bounces sound waves off prey and reveals information like its location, size, and shape.
2. Dolphins are intensely social mammals that communicate with squeaks, whistles, and clicks.
1. Dolphins are graceful, sleek swimmers that can reach speeds of more than 18 miles an hour