Dolphins vs. porpoises: What’s the difference

Here are some of the key differences between dolphins and porpoises.

Dolphins tend to be bigger

In general, dolphins are much bigger than porpoises. The largest dolphin species is the orca, also known as the killer whale, which can weigh up to 9,800 kilograms (21,600 pounds) and measure up to 10 metres (32.8 feet) in length.

For comparison, the smallest porpoise species-which is the smallest of all cetaceans-is the vaquita, which weighs up to 55 kilograms (120 pounds) as an adult and measures a maximum of 1.5 metres (five feet) from tip to tail.

Look closely and you'll spot differences in their appearance

One of the easiest ways to tell dolphins from porpoises is by looking at their faces and bodies. Dolphins have prominent beaks, while porpoises have more rounded heads. This means they have longer noses and bigger mouths.

Additionally, dolphins' dorsal fins are more curved and hook-shaped, whereas porpoises have dorsal fins that are more triangular.

They also have different types of teeth. Dolphins' teeth are pointed and cone-shaped, while porpoises have teeth shaped like spades. Generally, dolphins are longer and leaner than porpoises.

Porpoises live shorter lives

Compared to dolphins, porpoises tend to grow more quickly, breed at earlier ages, and live shorter lives.

Porpoises are a little less social

Porpoises are thought to be less social and less talkative than dolphins. Dolphins communicate using whistling sounds made through their blowholes, but scientists don't think that porpoises engage in this behaviour. Porpoises' blowholes may have structural differences that make it impossible.

Dolphins are also more likely to approach boats and show curiosity towards humans.

Porpoises are more shy and tend to avoid boats, except Dall's porpoises, which can commonly be seen swimming and bowriding alongside fast-moving boats.

What do dolphins and porpoises eat?

Toothed whales, including dolphins and porpoises, are carnivores that hunt and feed on other sea creatures. Both dolphins and porpoises consume a variety of prey, including schools of fish like herring, sand lance, mackerel, and squid.

The world's largest dolphin-the orca or killer whale-is a powerful predator. Some consume other marine mammals like seals, some eat only fish, and others prey on sharks and rays.

Vaquitas, the world's smallest porpoises, mainly eat fish, squid, and crustaceans. They are lower on the food chain and are sometimes preyed on by orcas and sharks.