Dolphin

There are about 40 species of dolphins known to exist in Earth's oceans and fresh water rivers. Some, like the bottlenose dolphin, are much more known to the public and to scientists. Research on dolphin intelligence, for instance, has been done predominantly with bottlenose dolphins in captivity. Others, like the rough-toothed dolphins that stranded in Florida and are featured in our film, are less understood. Scientists are still trying to discover, for example, where these animals can be found!

Similar to the herds of animals that have roamed the plains of Africa and North America, dolphins travel the ocean in communities of varying size; and they maintain societies for mating, feeding, detecting predators and nurturing their young. Some dolphins live in deep water, and are more likely to travel in large communities numbering in the hundreds or even thousands. Others live nearer to shore, traveling in bands of maybe dozens or hundreds. Generally, we know more about dolphins that live out their lives nearer our coastlines, than those that roam the wide ocean, far from our view.

All dolphins belong to the scientific order cetacea, which comprises both whales and dolphins. Dolphins are further subdivided into various families, the largest of which is called Delphinidae. There are 32 dolphins in this family, including the bottlenose, Atlantic spotted dolphins, dusky dolphins, spinners, even orcas (also known as killer whales), the largest of all dolphins. Porpoises and river dolphins belong to different families. Porpoises are usually smaller than dolphins, have different shaped teeth, no beak, and their dorsal fins are shaped differently (and sometimes porpoises have no dorsal fin).

Scientists tell us that the ancestors of dolphins, whales and porpoises were land mammals called ungulates, or hoofed animals. Fifty million years or so ago these animals adapted to the rising ocean, eventually becoming mammals of the sea.