Skip Navigation
North Carolina Aquariums
Toward a greater understanding of North Carolina's aquatic resources . . .
1-800-832-FISH (3474)
ask.gif (15643 bytes)
  What is the Difference Between a Dolphin and a Porpoise?

27 August 1997


Dolphins and porpoises are so similar that it is easy to confuse which is which.


In general, porpoises are smaller and plumper than dolphins, rarely reaching lengths of more than 6 feet and weights of more than 300 pounds. They have a rounded head and a small, triangular dorsal fin. Porpoises lack the "beak" characteristic of most dolphins, having a blunt snout instead.


dolph.jpg (68446 bytes)

The bottlenose dolphin is the most frequently spotted dolphin species in North Carolina's coastal waters.

Most species of dolphins have long, streamlined bodies, with a distinct pointed beak and a prominent dorsal fin with a curvature toward the tail. Their size varies from 4-26 feet with weights ranging from 70-1,500 pounds. Their teeth are sharp and cone-like in shape, in contrast to the spade-shaped, laterally-compressed teeth of the porpoise.


The bottlenose dolphin is the species of toothed whales most frequently spotted off the North Carolina coast. They are typically inshore species, and most often are observed in groups of about a dozen. Atlantic bottlenose dolphins are robust, though streamlined, growing to lengths of  8-11 feet with weights ranging from 500-1,000 pounds. They usually have light colored bellies and dark backs - colors that help them blend in with their surroundings. Their lower jaw projects beyond the upper, giving them the appearance of wearing a permanent grin. The bottlenose dolphin is a powerful swimmer that can often be spotted frolicking in the bow wave of a vessel or surfing on large waves.


While some confusion may exist about the differences between porpoises and dolphins, one thing is clear. Their numbers are dwindling due to direct hunting, accidental catches in nets of commercial fishing operations, and higher pollution levels in the earth's oceans and rivers. The Marine Mammal Protection Act, federal legislation enacted in 1972, protects porpoises, dolphins, and all marine mammals in U.S. waters.