Dolphins and porpoises can be easily confused at a glance. They are both small cetaceans and extremely intelligent. Each also have complex brains with a forehead called a melon. Using their melon, they can easily navigate using sonar (sound waves). However, you can use the 3 F’s (Face, Fin, and Figure) to help you visually tell the difference:

Face

Dolphins

Elongated “mouths” or “beaks”

Porpoises

Shorter, smaller mouths

Cone-shaped teeth

Spade-shaped teeth

Skull photos from Monterey Bay Aquarium


Fin

Dolphins

Curved, or hooked, dorsal fin

Common bottlenose dolphin

Porpoises

Triangular dorsal fin

Harbor porpoise

Figure

Dolphins

Generally leaner

Short-beaked common dolphin

Porpoises

More portly

Dall’s porpoise

Another difference between dolphins and porpoises is how they communicate. Dolphins can make whistling sounds through their blowholes to communicate with one another underwater. So far scientists have found porpoises to only communicate using clicks.


Generally, scientists agree that there are 32 dolphin species (plus five closely related species of river dolphin). Porpoise species are much fewer!

Check out the 7 porpoise species:

Now go out and find those porpoises!

Read more answers to Frequently Asked Questions here!

Artwork of porpoise and dolphin at top of page thanks to Rosemary Connelli, graphics of dolphins and porpoises thanks to NOAA Fisheries.

Ali Schuler
Ali Schuler

Ali has been working with the Whale SENSE Program since 2018. She has worked as a whale watch naturalist in both Alaska and Hawaii, and spent her master’s researching the effects of whale watching on humpback whales and conservation.