Do Sharks Have Ears? (Structure & Function)

Sharks, a key feature of many sea-related horror scenes, are well known for their ability to sense tiny amounts of blood in water from big distances. 

This talent and their known role as ‘apex predators’ is what gives many horror films their famous scenes of injured humans in shark-infested waters.

But, is it actually their smell that enables sharks to be one of the most deadly predators on the planet, or is it something else?

The part of the ear visible from the outside (called the ‘external ear’ or ‘auricle’) is the part that we most often associate with hearing. 

This means that, when it appears to be missing (like in many aquatic species, such as sharks), many people are misled into believing that this species has little, if any, ability to hear.

When it comes to sharks, the common misconception that they don’t have ears is completely false. In fact, sharks actually have a much more sensitive hearing ability than humans! Studies have shown that sharks can hear struggling prey that are up to 800 feet away. Interestingly, sharks can also hear lower frequency sounds much more efficiently than even us humans can!

So, not everything has to be seen to be believed after all!

Now we’ve debunked the myth that sharks, despite how they may look from the outside, aren’t as alien as we may think from the inside, let’s delve deeper.

Do All Sharks Have Ears?

Although different species of shark may look very different from the outside, they all share the basic need to hunt prey. 

Despite many of us believing that their acute sense of smell is key to them finding their food, a shark’s sense of hearing also plays a key role in their ability to source their food.

In short, yes, all sharks have ears. Whether that be the ginormous whale shark, the famous great white shark, or the pretty tiger shark, all sharks have ears. 

The thing which causes confusion could be the lack of the external ear (we’ll talk about this in the next section).

Shark Ear Structure And Function

All that’s visible of a shark’s auditory system from the outside is the two small holes (one on either side) just behind their eyes. 

This is just like in humans, but they don’t have the external ear cartilage we humans do.

In humans, the main roles of the external part of the ear are to:

  • Direct the sound into the eardrum
  • Localize the direction of sound

Sharks don’t have a need for an external ear cartilage as we know it as they have something called a ‘lateral line’ which serves a similar purpose. 

The lateral line is just under the skin from a shark’s nose, along both sides of its body.

Interestingly, the lateral line has another sensory-related purpose. The lateral line can be used to detect special odor molecules or ‘plumes’

Experts have shown that a shark’s ability to use their lateral line to help locate their prey is vital in their success.

Studies have even shown that by disturbing the ability of a shark to use their lateral line, they become ‘severely handicapped’ in their capability to locate the origin of a smell. 

Special cells called ‘hair cells’ play an important role in both the lateral lines and a shark’s inner ear. 

These cells are highly adapted to detect movement and then pass it down a long line of cells (like in a game of dominoes). 

The end result of this process is for the brain to receive a signal that movement has been detected nearby.

Streptomycin, a common antibiotic used in human medicine, in high amounts is known to disrupt the proper functioning of hearing in humans and the proper workings of the later line, both of which are linked to hair cells.

One difference between the inner ear of a shark and a human is its parts. In sharks, its components are considered organs, whilst in humans, they are bones. 

Us humans have 3 bones (the malleus, incus, and stapes) and sharks have three cartilage tubes which help them both to balance and detect sound. 

These parts are called:

  • Uticulus
  • Sacculus
  • Lagena

The above parts of a shark’s ear are arranged in a way that means they can detect movement (such as a potential prey item) in three dimensions.

Another important part of a shark’s ear is the ‘Otolith’. The Otolith is attached to parts of cartilage and its job is mainly to help a shark orientate itself.

In Conclusion

In short, the main differences between a shark ear and a human one are:

  • The absence of a visible external ear
  • Sharks’ ears are able to hear at a much lower frequency than humans can

While we’re on the subject of humans, some experts have hypothesized that human activities such as from ships and fishing activities in water could actually disturb the highly sensitive hearing apparatus of a shark. 

Overall, more research still needs to be done on this topic though.

But, does water interfere with a shark’s ability to hear? 

No, in fact, sound in water actually travels faster and further than out of the water! And of course, a shark’s body is completely well adapted to their life underwater. 

Have you enjoyed hearing (pardon the pun!) about one of the many specialized structures seen in sharks? Tell us about it in the comments below!

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