Originally designed to live on land, marine mammals are a diverse, charismatic group of animals that include more than 120 species.
The animals share key characteristics of land mammals. They have hair, breathe air, give birth to live young, which feed off mother's milk when young. They have warm bodies and usually thick blubber to keep their body temperatures high.
The bottlenose dolphin is probably the most widely recognized marine mammal, easily spotted just offshore from beaches around the world. Small groups of 20 or less can live in close proximity to shorelines, but groups living more offshore can reach several hundred.
Bottlenose dolphin calves stay with their mothers for up to six years, learning how to hunt and become good dolphin citizens. Full-grown dolphins reach eight to 12 feet in length and can weigh up to 1,430 pounds.
The bottlenose dolphin is protected in U.S. waters.