Is It a Dolphin or Porpoise?

Can you believe that in our advanced society of science that not all scientists agree on what is a dolphin or a porpoise? There are some holdouts and which is which. So what is the difference you ask? There are some traits that are generally agreed to be specific to dolphins and some specific to porpoises.

Porpoise on top, Dolphin on bottom

Firstly, if you look at their mouths, the snout of each animal is referred to as the beak (kind of like a bird). The dolphin's beak is longer and sleeker than the porpoise's. Secondly, look at their dorsal fin (the fin on their backs). The dolphin's tends to be curved or hooked, whereas the porpoise fin tends to be more of a triangle. Thirdly, look at the actual body shape. The dolphin tends to be leaner and sleeker overall, whereas the porpoise seems to be more plump and not as sleek. Fourthly, their teeth. The dolphin has cone-shaped teeth, but the porpoise has shorter spade-shaped teeth. Fifthly, listen to them. The dolphins are very talkative and make all sorts of sounds. The porpoise doesn't seem to do this, and it's believed it's because of the way their heads are shaped. The dolphin's sounds come from the blowhole on the top of their head, but the porpoise head is shaped differently, which is why that theory is believed by most.

On the other hand, there are two big similarities of dolphins and porpoises. Firstly, they are both highly intelligent creatures. They learn and adapt well, they are very social and curious, they form close bonds, and they are able to generate and effectively use sonar. Secondly, they are similar in size and shape. They both belong to the order Cetacea which includes whales also. All three are marine mammals that share the same general habitat.

Generally, it is agreed that there are 32 species of dolphin (plus 5 species of river dolphins), which includes the largest dolphin: the killer whale (which is actually a dolphin). On the other hand, it is generally agreed that there are only 6 species of porpoise.

All the order of Cetacea (whales, dolphins, porpoises)