Dolphins and porpoises are found in every ocean of the world. From the deep Antarctic Ocean, to South Pacific lagoons, and the bays and fjords of British Columbia's coastline. They both belong to the same scientific order, Cetacea.

Both dolphins and porpoises are mammals. Even though they both live in the ocean, they are not fish. They do not have breathing gills. They have lungs and breathe air. Both also give birth to live young and nurse those young. A mammal is also characterized by having the prescence of hair: when dolphins and porpoises are small, there are small hair follicles.

Porpoises and dolphins are classified into two different families. The porpoises are in the family Phocoenidae and the dolphins are in the family Delphinidae. When separated at the family level, dolphins and porpoises are as physically different as cats and dogs.

The dolphin, rather than the porpoise, is often seen in marine animal shows. This comes back to the idea that dolphins tend to show a lesser fear of man than porpoises. This is often why dolphins, not porpoises, get stuck in tuna nets. For this reason dolphins are widely studied whereas porpoises are not.

There are many behavior differences as well as physical differences. For the most part, porpoises are shy animals. They do not often approach people or boats. The dolphin, on the other hand, if often seen riding the bow wave of fishing boats. We rarely see porpoises at the surface unless they are coming up for a breath.

Both dolphins and porpoises have an unique social order. While both use their teeth as a form of tactile communication within the social group, scientists believe that unlike dolphins, porpoises do not use underwater whistles to communicate. Dolphins actually use their blowholes to create a whistling noise, which is used particularly often to communicate between mother and calf.

Dolphins and porpoises have a lot in common. There are some diffences, but the similarities among their behavior and looks outweigh the minute differences. You are more likely to see a dolphin, both in the wild and captivity.