Dolphins and Porpoises
These marine mammals (cetaceans) are closely related to whales. There are 40 species/subspecies of dolphins and only 6 of porpoises. Though they may appear similar at first glance, these mammals have many physical and social differences. Both are extremely intelligent and have large, complex brains.
Dolphins have conical teeth, a curved dorsal fin and a long beak and bulb-like head. They can range in size from 4 to 30 feet.
Porpoises have spade-shaped teeth, a triangular dorsal fin and a small, rounded jaw and head. They can range from about 5 to 8 feet long.
Dolphins are extremely social and live in pods or superpods, depending on the availability of food. They communicate with several vocalizations, including clicks, whistles and ultrasonic sounds, by which they locate each other as well as prey. Dolphins can establish strong social bonds.
Porpoises are shy and travel alone or in very small groups which change frequently. They also use echolocation to find prey and sometimes to coordinate their group activity. They generally do not establish social bonds.
Dolphins are playful with each other, with swimmers and sometimes with other creatures such as sea birds and turtles. They often ride the bow waves of boats. These marine mammals can live in aquariums and can be trained to perform a variety of acrobatic tricks as well as underwater military tasks.
Porpoises do not generally do well in captivity and are less sociable and trainable.
