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:
Elongated “mouths” or “beaks”
Shorter, smaller mouths
Skull photos from Monterey Bay Aquarium
Curved, or hooked, dorsal fin
Triangular dorsal fin
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.