All oceans of the world


Some live mainly along coastlines but others live far at sea

It’s all relative

You might not realize that dolphins are closely related to whales. The scientific order, called Cetacea, includes dolphins, whales, and porpoises. The dolphin family Delphinidae has 36 species in all. It can get confusing at times, because some members of the dolphin family have the word whale in their common name. In fact, the largest dolphin is the killer whale! Depending on the species, dolphins range in color from white, pearl, and pink to darker shades of brown, gray, blue, and black.

Bodies made for swimming

Dolphins have smooth skin, flippers, and a dorsal fin. They have a long, slender snout with about 100 teeth, and a streamlined body. The single blowhole on top of their head has a flap that opens to reveal a pair of nostrils, which dolphins use for breathing when they surface.

Dolphin teeth are cone shaped with sharp points that help to hold prey.
Every dolphin has its own distinct whistle to communicate with others in its pod.
The three best-known dolphins—white-sided dolphins, bottlenose dolphins, and spinner dolphins—can be seen in marine mammal demonstrations, on television shows, and in movies.
Dolphins don’t drink sea water. They get the water they need from the fish they eat.

The San Diego Zoo does not have dolphins in its collection.

Hunting, pollution, and human development along coastlines and rivers have seriously impacted some dolphin populations. Dams, habitat loss, and fishing nets are also hurting dolphins. In 2000, many countries joined the International Dolphin Conservation Program, which is an international agreement to reduce the numbers of dolphins that are lost through tuna fishing. The Hector's dolphin Cephalorhynchus hectori is endangered. Some, like the bottlenose dolphin Tursiops truncatus, are protected in US waters by the Marine Mammal Protection Act of 1972.