Dolphins are types of cetacean mammals that are closely related to porpoises and whales. They range in size from 4 feet to 30 feet and weigh up to 10 tons. Dolphins have a single blowhole, cone-shaped teeth and a pronounced beak. Although dolphins don't have body hair, they have hair follicles that may perform sensory functions. Dolphins are typically gray in color and live in both pelagic and coastal water.
Dolphins have streamlined bodies that are adapted for fast swimming. The fluke, or tail fin, provides for propulsion, while the pectoral fins are utilized for directional control. The dolphin's diet consists mainly of squid and fish. Dolphins swallow their food whole instead of chewing. Dolphins have excellent eyesight and hearing that is 10 times stronger than humans. In addition, all dolphins are capable of utilizing echolocation. Dolphins have a well-developed sense of touch and have a sense of taste, despite not having a sense of smell.
Dolphins are very social creatures. They typically live and travel together in groups of between two and 40, with some dolphin pods containing as many as several hundred dolphins. Dolphins rely on social interaction to hunt and defend themselves against predators. The strength of dolphins' social bonds is illustrated by the fact that dolphins stay with other dolphins that are injured or sick and even carry them to the surface to help them breathe. The bottlenose dolphin is perhaps the most well-known dolphin species. Other dolphin species include spinner dolphin, common dolphin, striped dolphin, dusky dolphin and killer whale.