Ask Asta: What's the difference between porpoises and dolphins?

Find out more about a dolphin's fins and a porpoise's purpose below!






Dolphins and Porpoises may not seem all that different when you view them in the water.
But if you look a little closer, you can notice some distinct differences between these two unique species.

Both dolphins and porpoises originate from a lineage of of warm blooded, carnivorous ocean creatures, a lineage they share with whales, seals and sea lions in the order Cetacea (derived from the Greek word Ketos, meaning "large sea creature"). Both species also belong to the suborder Odontoceti, a group of animals known as the "toothed whales."

Porpoises and dolphins share some common characteristics as well. They have similar body shapes, and often are found foraging and swimming in the same parts of the ocean. They are also both highly intelligent and use echolocation to interact with other members of their family or "pod" over large distances under water. 

When it comes to behavior, attitude and lifestyle, these two animals show some distinct differences. Check out how dolphins and porpoises compare in our "porpoise"ful comparisons chart!

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Dolphins 
(From the family Delphinidae)

Number of unique species: 41

• Size: Dolphins range in size from 4ft (River Dolphins) up to almost 30 ft (Orcas, which are not whales, but actually a large dolphin species!) 
  

• Fin Shape: Dolphins have a softly sloping dorsal fin extending toward it's tail. 
  

• Teeth: Dolphin have large mouths, with 80-100 interlocking conical teeth. Their teeth have no differentiation, meaning that they are used primarily to catch and hold their prey before swallowing. 
  

• Head Shape: Dolphins have a large, bulbous "melon" with a long snout or "rostrum" which contains long jaws. This jaw shape gives dolphins their distinct smiling happy look! 
  

• Sociability: Dolphins love to congregate in large groups, and are almost always found in groups. They communicate through a complicated language of clicks, whistles and bubbles, and use echolocation to find food, and one another. 
  

•  Behavior: Dolphins are wildly acrobatic, jumping and playing at the surface of the water  or riding the wake of moving boats and vessels.
  

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Porpoises
(From the family Phocoenidae)

Number of Unique Species: 6

• Size: 3.9-8 ft. Porpoises have a wider, stockier body than dolphins do. Some species also have humps on their dorsal (upper) side and their ventral (bottom) side near the tail. 
  
• Fin Shape: Porpoises have a sharper, more triangular dorsal fin, similar to that of a shark.
  

• Teeth: Porpoises have 35-50 spade shaped teeth that are usually flat and sharp. Each tooth is separated by rigid, protruding growths known as "gum teeth". Gum teeth are thought to be used to aid the small teeth in grasping slippery prey, like squid or small fish. 
  
• Head Shape:  Porpoises have a round head, a less prominent melon and amuch smaller jawline than dolphins do. 
  

• Sociability: Porpoises are usually spotted alone or in small groups of 2-12. The shape of their blowhole does not allow them to create the same whistle and pop sounds that dolphins use to communicate. 
  

• Behavior: Porpoises are usually very shy and will generally swim away from vessels as they approach. Dall's Porpoises, however, will sometimes congregate around loud vessels in the waters of the Salish Sea to wave surf!
  

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Photo Courtesy of wild whales.org.

Video By Bioexpedition.

Did you know…

that both Porpoises and Dolphins can end up as prey for another species of Dolphin? 



The largest species of dolphin on the planet actually go by the name "Killer whale" or Orcinus Orca in fancy latin! 

 Orcas are notoriously efficient team predators, meaning that they often work together to herd and hunt other marine mammals, like seals, sea lions and even porpoises and dolphins. Check out this amazing video of Pacific White Sided Dolphins being hunted by a hungry pod of Orcas! 
Video courtesy of youtube  from 11MOAX.

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References:













NOAA online. Last Updated March 14, 2014. "What's the difference between dolphins and porpoises?"Retrieved March 28 2014. http://oceanservice.noaa.gov/facts/dolphin_porpoise.html

Wonderopolis."How Are Dolphins and Porpoises Different?"Retrieved March 28 2014. http://wonderopolis.org/wonder/whats-the-difference-between-dolphins-and-porpoises/

BC Cetacean Sightings Network. June 17, 2013. "Dolphin Vs. Porpoise: What's the Difference?" Retrieved March 28, 2014.
http://wildwhales.org/2013/06/dolphin-vs-porpoise-whats-the-difference/


Diffen: Compare Anything Site. 2014.  "Dolphin Vs. Porpoise." Retrieved March 28, 2014. http://www.diffen.com/difference/Dolphin_vs_Porpoise

Dolphins World Online. 2014. "What is the Difference Between A Dolphin and A Porpoise?" Retreived April 2, 2014.
http://www.diffen.com/difference/Dolphin_vs_Porpoise

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