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The 8 Different Types of Sharks, Explained

Posted by Ashley Robinson | Dec 3, 2019 1:00:00 PM

General Education

 

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Sharks have been around for more than 450 million years, which means there’s a lot to know about the ocean’s most feared predators. While they’ve been the victims of bad press in recent years, it turns out that sharks are fascinating creatures with unique traits, qualities, and behaviors. 

How many types of sharks are there? There are hundreds of species of sharks, and they all fit into eight distinct orders: Carcharhiniformes, Heterodontiformes, Hexanchiformes, Lamniformes, Orectolobiformes, Pristiophoriformes, Squaliformes, and Squatiniformes. 

In this article, we’ll discuss each of the eight orders of sharks, give you the distinguishing characteristics of each, and then teach you what makes all types of sharks different from other species of fish. Finally, we’ll give you a quick list of FAQs about sharks! 

So...let’s dive in. 


 

What Are the 8 Different Types of Sharks? 

Sharks are a type of fish and come in all shapes, sizes, and in every ocean in the world. 

But what is a shark, exactly? In general, all sharks—from the smallest dwarf lanternshark to the largest whale shark--have some traits in common. The shared traits that define sharks are: 

  • A skeleton made of cartilage instead of bone
  • Five to seven gills 
  • Rigid fins
  • Dermal denticles, or placoid scales, that are shaped like teeth and feel like sandpaper  
  • Enhanced senses, including the ability to sense electric fields (called electroreception

According to the Smithsonian Institute, there are more than 500 species of sharks alive today. More importantly, each of those species fit into one of eight different orders, or categories. 

Let’s take a closer look at the eight kinds of sharks you can find in the ocean today. We’ll even give you some notable shark species in each category! 

 

Shark Type 1: Carcharhiniformes

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The tiger shark is one of the most well-known types of Charcharhiniformes. It's probably because scientists have found all sorts of things in their stomachs, including license plates and pieces of armor. (Albert Kok / Wikimedia)

 

These types of sharks are the largest order of sharks with more than 270 species falling into this group. These sharks live in almost every type of marine ecology on the planet: from the frigid open waters of the Atlantic all the way to brackish rivers. These sharks can also be as tiny as 18 inches or as long as 20 feet, depending on the species. 

Carcharhiniformes are characterized by having five gills, two dorsal fins, an anal fin, and a nictating membrane over their eyes. This membrane covers the eye to protect it from damage while still allowing the shark to see. Sharks in this order tend to have longer snouts, and they’re known for being adaptable to many environments.

Notable species of Carcharhiniformes include: 

 

Shark Type 2: Heterodontiformes

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Heterodontiformes like this Port Jackson shark are small...and known for being pretty dang cute.
(Yzx / Wikimedia)

 

Hederodotiformes, more commonly referred to as “bullhead sharks,” usually live in rocky reef formations in either the Pacific or Indian oceans. They tend to be small, with the largest shark in this order coming in at only 5 feet long. Their size, habitat, and appearance mean they’re often considered “cute,” “clumsy” sharks—they’re definitely not the sleek killing machines that many Charcharhiniforms are! 

So what do Heterodontiformes look like? These kinds of sharks have short snouts and a large brow over their eyes—hence the name “bullhead shark.” They also have small spiracles to help them breathe, a small spine on each dorsal fin, and a groove running from their nostrils to their mouths. Finally, they tend to have peg-like teeth which help them eat hard-shelled prey, which they hunt primarily at night. 

Notable species of Heterodontiformes include: 

 

Shark Type 3: Hexanchiformes

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Broadnose Sevengills sharks like this guy have—you guessed it!—seven gills. That characteristic is unique to Hexanchiformes! (Aaron Scheiner / Wikimedia)

 

You can quickly spot Hexanchiformes by the number of gills they have. While most sharks sport five gills, Hexanchiformes have either six or seven gill slits. These sharks tend to be large and range from eight feet to 16 feet long. Additionally, they only have one dorsal fin (instead of the more common set of two). They’re often considered one of the most primitive types of sharks still alive today. 

These types of sharks have thin, eel-like bodies and favor the deep, cold waters of the Atlantic, Pacific, and Indian Oceans. That means they’re particularly hard for scientists to track, so we don’t know much about them. We do know that they feed on fish, other sharks and rays, and crustaceans. We also know that these sharks are ovoviviparous, meaning that their eggs hatch inside of a female’s body and are born alive. 

Notable species of Hexanchiformes include: 

 

Shark Type 4: Lamniformes

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Great White sharks, which are a type of mackerel shark, are probably the most famous shark in the world. 

 

Lamniformes are an order of shark that contains some of the world’s best known—and most notorious—shark species. These sharks are also known as “mackerel sharks,” and they have a wide variety of species and body types ranging from the sleek, predatory Great White shark to the giant filter-feeding sharks, like Megamouth sharks. 

Because Lamniformes encompass a huge variety of species, their characteristics tend to be what you might consider “typical” of sharks you picture in your imagination. They have two dorsal fins, an anal fin, and five gills. With the exception of the filter feeding Lamniformes, most members of this group are the apex predators in their habitats, which tend to be warm and tropical seas. 

These sharks range in size from three feet to 32 feet and tend to have body temperatures that are warmer than the surrounding water temperature (although they aren’t warm blooded). Lastly, their diets are as varied as their shapes and sizes: the filter feeders eat plankton and other microorganisms, while their fellow mackerel sharks have been known to chow down on sea lions and tuna. 

Notable species of Lamniformes include: 

 

Shark Type 5: Orectolobiformes

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Whale sharks, which are Orectolobiformes, are the largest sharks currently in existence. They can grow up to 33 feet long! 

 

Orectolobiformes, or “carpet sharks,” range from the largest shark currently in existence (the whale shark) all the way to the diminutive white-spotted bamboo shark. Despite their size differences, all these kinds of sharks tend to live in warmer waters, though the behavior between types of carpet sharks tends to vary pretty significantly. For instance, whale sharks eat plankton and are considered pelagic, meaning they live in open water. In contrast, bamboo sharks live in coral reefs and eat small fish and invertebrates! 

So what do Orectolobiformes have in common? Their most notable feature is their mouths, which are situated at the very front of their heads and don’t extend behind their eyes. They also sport barbels by their mouths, which work like whiskers to help the sharks find food. Carpet sharks also have an extremely long caudal fin, which is the top lobe of their tails. For many species, their caudal fin is almost the same length as their bodies! Additionally, carpet sharks tend to sport eye-catching patterns, much like carpet...hence their more common name. 

Notable species of Orectolobiformes include: 

 

Shark Type 6: Pristiophoriformes 

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Pristiophoriformes are easy to spot: just look for their distinctive, saw-like snouts.

(Diliff / Wikimedia

 

Pristiophoriformes are also known as “sawsharks,” and they tend to live in temperate and tropical oceans. This is a small group of species, all of which are characterized by having a saw-like snout, or rostrum. The snout is edged in teeth, and they use their snout like a saw to slash their prey. A shawshark’s teeth vary in size depending on the species, but like most sharks, lost teeth are replaced almost immediately. 

Pristiophoriformes have a few other notable features, too. They boast long, moustache-like barbels and tend to stay fairly small, reaching about 5 feet long. They’re also ovoviviparous and give birth to live young. But their most distinctive feature is their snout, so if you see sharks with saw-like noses, then you'll know you’re looking at Pristiophoriformes!

Notable species of Pristiophoriformes include: 

 

Shark Type 7: Squaliformes

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Greenland sharks, which are Heterodontiformes, can live up to 400 years in the right conditions. That makes them the longest-living sharks known to man. (Hemming1952 / Wikimedia)

 

Squaliformes are an order comprised of 126 different shark species. Like Heterodontiformes, Squaliformes have spines on both their dorsal fins and between five and seven gill slits. Unlike their cousins, however, these sharks tend to stick to deep ocean water (below 400 meters) and live close to the ocean floor. Because these sharks live in such remote environments, little is known about many of the species in this order. 

Since there are so many species of Squaliformes, they vary considerably in size and shape. For example, the dwarf lanternshark is the smallest species of shark in the world and only grow to be 8 inches long. In comparison, the Greenland shark can grow to be more than 21 feet long...which is longer than the biggest Great White shark on record. 

The most distinct characteristic of Squaliformes is that many species bioluminesce, or glow in the dark. This is the same adaptation that allows lightning bugs to glow! Scientists believe that this adaptation can help sharks recognize other members of their species, avoid predators, and even lure in prey. 

Notable species of Squaliformes include: 

 

Shark Type 8: Squatiniformes

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Squatiniformes, like this Australian angelshark, are often confused with rays. The best way is to look at their pectoral fins. Angelsharks have their fins attached to their torsos, not their heads (which is the case in rays). (Yzk / Wikimedia)

 

The last order of sharks are the Squatiniformes, which are more commonly known as angelsharks. This order contains just 13 species, all of which fall within the same family. 

It’s easy to confuse Squatiniformes with skates or rays because they have a flat body with large pectoral fins that look almost like wings. (Hence the name “angelshark!”) These sharks grow to be between 5 and 7 feet long, have horizontal pectoral and pelvic fins, and no anal fin (so they can rest flat on the ocean bottom). Like their ray cousins, Squatiniformes live on the ocean floor and prefer sandy areas where they can hide and ambush their prey. 

So if they look so much like rays and skates, how can you tell them apart. The trick is to look at the pectoral fins. In rays, the pectoral fins are attached to the animal’s head. Squatiniformes, however, have pectoral fins that attach to their torsos instead. Unfortunately, angelsharks are some of the most endangered shark species because they’re easily caught in fishing nets. 

Notable species of Squatiniformes include: 

 

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Shark FAQs Answered 

Now that you’ve learned all about the eight different types of sharks and their characteristics, it’s time for us to address some of the most frequently asked questions about sharks. 

 

Are Sharks and Stingrays Related? 

Yes! Sharks and rays are both Chondrichthyes, meaning their skeletons are made of cartilage. 

 

Why Aren’t There Many Complete Shark Fossils? 

There are shark fossils, which isn’t surprising considering sharks have been around for 480 million years. What you’ve probably noticed is that fossilized shark skeletons are incredibly rare. That’s because cartilage is held together by collagen, which decomposes once the shark dies. Once that happens, the shark’s skeleton basically falls apart. 

Having said that, shark teeth are one of the most common vertebrate fossils you can find. Shark teeth are made of the same elements as human teeth, and thus are more likely to be preserved. Next time you’re at the beach, be sure to keep an eye out for your own piece of geologic history. 

 

How Are Sharks Different From Other Fish? 

Sharks are different from fish because fish (unlike sharks!) have a bony skeleton. That’s one of the reasons sharks only swim forward—their pectoral fins are inflexible, so they can’t use them to swim backward. 

 

What Types of Shark Teeth Are There? 

There are around 440 kinds of shark species that exist today, and most of them have different types of teeth. Actually, shark species’ teeth are unique enough that scientists can use their puncture patterns to identify bite marks on animal carcasses...and sometimes people. 

The type of tooth a shark has tells us a lot about what sharks eat. Great white sharks and tiger sharks, for example, have triangular, serrated teeth—good for biting into large mammals and ripping off chunks of flesh. Basking sharks, on the other hand, have tiny teeth that they don’t even use! These sharks feed off of plankton and other microscopic organisms that they filter out of the water. 

The one thing all types of sharks have in common is that they have rows of teeth, and their teeth are constantly replaced. The rate of replacement varies from shark to shark, but they will continue to lose and replace teeth continually throughout their lifetimes. In fact, sharks can lose up to 50,000 teeth in their lifetime! 

 

Do Sharks Eat People? 

If you’ve seen Jaws, then you might think that sharks are just lurking in the water waiting for a tasty human to jump in. But that couldn’t be further from the truth. There were only 130 shark attacks recorded in 2018, only a handful of which were fatal. You’re more likely to be killed by a deer than you are by a shark!

 

Are Sharks Endangered? 

Unfortunately, overfishing and the shark fin trade has left many shark species in danger of going extinct. The sad fact is that close to 100 million sharks are killed each year.

One of the best ways you can help protect different types of sharks is by learning more about them. Luckily, organizations like OSEARCH allow you to get to know sharks better—and you can even track where they swim through OSEARCH’s app

Another way you can help sharks is by buying ethically sourced seafood (that prevents sharks from being caught and killed as bycatch). You can also contact your government representatives and ask for pro-shark legislation, like banning the sale and consumption of shark fin soup. And lastly, you can volunteer with and/or donate to shark conservation organizations, like WildAid or the Wildlife Conservation Society

 

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What's Next?

If you love sharks and want to work with them, then you might consider majoring in biology, marine biology, or zoology. But choosing a major can be a tricky process! Let us help you make sense of choosing a major that's a good fit for you and for your future goals.

But in the meantime, it's a good idea to really start brushing up on your biology skills. You should definitely consider taking upper-level and advanced biology classes in high school so that you're prepared for college. Check out our complete guides to AP Biology and IB Biology so that you can decide which track is right for you.

Finally, it's important that you spend as much time thinking about where to go to school as you do actually applying for school! Here are some tips for narrowing down your school list (and here's our advice for making a school list in the first place).  

 

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Ashley Robinson
About the Author

Ashley Sufflé Robinson has a Ph.D. in 19th Century English Literature. As a content writer for PrepScholar, Ashley is passionate about giving college-bound students the in-depth information they need to get into the school of their dreams.



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