Porpoises are incredibly unique animals that share many characteristics with the well-known dolphin. But how do they compare in the teeth department?
Porpoises have between 60 to 120 teeth. These teeth resemble the shape of a spade, and the tip is rounded and flattened. They use their teeth to eat a variety of fish, squid, octopi, and crustaceans.
In fact, the unique shape of porpoise teeth represents one of the key differences between them and dolphins. To learn all you’ll ever need to know about porpoise teeth, read on.
Porpoise Teeth: An Overview
Okay, so you’re here for a reason. Let’s go over everything you’ll need to know about porpoise teeth and just what they use them for.
Porpoise Teeth and Age
Did you know that examining porpoise teeth can help tell you how old the porpoise is? This is done by analyzing the Growth Layer Groups (GLGs) on the teeth. The average age of the porpoise in the wild is 20, but the oldest recorded age is 24 years.
Note: There is a problem with using teeth to find the age of an older porpoise, as the amount of tissue and mineral resorption in older animals can make it difficult to pinpoint the exact age of the porpoise.
Porpoise Teeth and Diet
Porpoises eat mostly non-spiny fish such as herring, pollack, hake, cod, and sardines. They also eat squid, octopi, and crustaceans on occasion.
One fascinating fact is that Porpoises don’t use their teeth to eat. Instead, they are used to grab their prey, which they then swallow whole.
While the shape of the teeth isn’t confirmed to aid in their feeding habits, all porpoises have rigid growths between their teeth, called “gum teeth.” These are believed to help the porpoise grasp more slippery prey, such as squid.
A type of fish called a large flatfish is dangerous for porpoises. Because the porpoise swallows its food whole, they tend to choke on the flatfish.
This is why they will stick to smaller fish, though this will require them to consume large quantities to satisfy their needs. Porpoises need to eat up to 10% of their body weight every day.
Porpoise vs. Dolphin: What’s the Difference (Especially With Their Teeth)?
What is the difference between the two? It’s a question that isn’t uncommon among marine mammal lovers.
The answer comes down to the specific species of both dolphin and porpoise. Many think of the bottled-nose dolphin when they think of the species, but there are other dolphins that can look more like porpoises.
While these physical distinctions for either animal can differ between species, here is a list of common differences:
- Dolphins have coned teeth as porpoise have spade-shaped teeth,
- Porpoises are generally smaller in length than dolphins
- Dolphins will typically have a curved dorsal fin; a porpoise’s will be more triangular
- Porpoise body types tend to be more portly, while a dolphin will be leaner
There are many other differences between the two animals, including habitats, eating habits, mating and birthing habits, and much more.
How Many Porpoise Species Are There?
There are six species of porpoise, and each of them is unique in their own way. Well, except the fact in that they ALL have teeth.
Porpoises can be found in both saltwater and freshwater habitats. The finless porpoise can be found in the Indian Ocean, while the Harbor porpoise can sometimes be found in the Arctic as well the north Atlantic Ocean. The Dall’s porpoise can be found in the Pacific Ocean.
The speckled and harbor porpoises prefer colder waters, which is why they can be found in more northern regions. Some finless porpoises can be found in the Yellow Sea between China and Korea.
Dolphins, on the other hand, have 36 species worldwide.
Can You Spot a Porpoise in the Wild?
Spotting a porpoise in the wild can be difficult. This is because of their shy nature as well as not jumping from the water like dolphins do. However, similar to dolphins, you may occasionally see the dorsal fin of a porpoise stick out of the water in the wild!
Porpoise Conservation Efforts
The biggest danger that the porpoise faces are fishing nets and commercial fishing. Porpoises caught in the nets have the potential to drown if they can’t free themselves. It isn’t known how many porpoises are left exactly; however, there is the Vaquita porpoise that is in danger of becoming extinct.
The Vaquita is the smallest porpoise species, and they can be found in the Gulf of California. The biggest danger to the Vaquita are gillnets. These are fishing nets that trap the porpoise and make it difficult for them to escape. It is estimated that all six species of porpoise have been fatally trapped by a gillnet at some point.
In some regions of the world, fishermen are required to have devices called pingers to help keep porpoises away from other types of fishing nets. These devices are meant to give off sounds that scare off the porpoises in the area.
However, over time marine mammals have learned that the sounds made by the pingers indicate a potential for a large quantity of fish ready to be eaten.
Some Things You May Not Know About Porpoises
Porpoise Size Facts
- Most porpoises will grow to be 5 to 6.6 ft (1.5 to 2 m) and weigh 110 to 265 lbs (50 to 120 kg).
- The smallest porpoise species is the Vaquita, and they can grow to be 4-5 ft (1.2-1.5 m) and weigh about 110 lbs (50 kg).
- It’s also possible for a fully grown porpoise to weigh over 400 lbs (181m).
Porpoise Echolocation Facts
- Porpoises are similar to other whales because they also use echolocation for hunting and seeing in the ocean. However, porpoises use a different kind of echolocation.
- Unlike the dolphin, who uses clicks to communicate, the porpoise’s echolocation operates on a frequency that humans and other animals can’t hear.
- This type of echolocation likely evolved from years of being hunted by killer whales and sharks. It is believed that the porpoise’s echolocation developed this way as a means of survival to avoid detection by their biggest ocean threat, the killer whale.
Porpoise Temperament Facts
- Porpoises are shy animals, unlike the dolphin. Porpoises will stay away from boats and won’t jump completely from the water.
- Some species of porpoises, such as the harbor porpoise, will relatively stick to traveling alone. However, they have been seen in small groups of up to five members.
- Other species of porpoise, like the Dall’s porpoise, are more friendly. They enjoy bow riding and will approach boats in the wild!
Other Interesting Porpoise Facts
- The word porpoise comes from the Latin word for pig and in Old French, means “sea-hog, mere swine.”.
- Finless porpoises look similar to other porpoises, except they do not have the dorsal fin. In addition, Finless porpoises will appear to be
black, but they are, in fact, grey with some blue spots.
- The Dall’s porpoise is the fastest porpoise species.
- Male harbor porpoises are smaller than females.
- Porpoises are capable of diving to depths of 650ft (198m) for food.
Wrapping It Up
Hopefully, you have learned some interesting new things about porpoises and their unique teeth!
There is always more to learn by studying the porpoise. However, if you happen to come across these animals in the wild, don’t approach them (unless they friendly come riding next to you in a boat)! Always exercise caution with wild animals.
Read, A. J. (2009). Porpoises, overview. In Encyclopedia of marine mammals (pp. 920-923). Academic Press.
Jefferson, T. A., Robertson, K. M., & Wang, J. Y. (2002). Growth and reproduction of the finless porpoise in southern China. Raffles Bulletin of Zoology, 50, 105-114.
Jefferson, T. A., & Curry, B. E. (1994). A global review of porpoise (Cetacea: Phocoenidae) mortality in gillnets. Biological Conservation, 67(2), 167-183.