DOLPHIN is any of the toothed whales belonging to the mammal family Delphinidae (oceanic dolphins) as well as the families Platanistidae and Iniidae, the two that contain the river dolphins. Of the nearly 40 species of dolphins in the Delphinidae, 6 are commonly called whales, including the killer whale and the pilot whale. The name dolphin is also applied to members of the fish genus Coryphaena (family Coryphaenidae).
Most dolphins are small, measuring less than 3 meters (10 feet) in length, and have spindle-shaped bodies, beaklike snouts (rostrums), and simple needlelike teeth.
Some of these cetaceans are occasionally called PORPOISES, but scientists prefer to use this term as the common name for the six species in the family Phocoenidae.
What’s the difference?
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Dolphins |
Porpoises |
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elongated “beaks” and cone-shaped teeth |
smaller mouths and spade-shaped teeth |
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curved dorsal fin |
triangular dorsal fin |
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bodies are leaner |
Bodies are portly |
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Talkative and make whistling sounds through their blowholes to communicate with one another underwater |
Do not do this, some think this may be due to structural differences in the porpoise’s blowhole |
Dolphins and porpoises have many similarities, one of which is their extreme intelligence. Both have large, complex brains and a structure in their foreheads, called the melon, with which they focus sound waves used to navigate their underwater world.
