Resting Sharks: Can Sharks Stop Swimming?

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Sharks are some of the most fascinating predators in our oceans, they have a fierce reputation and are known to be at the top of the food chain.

In this post, we’re going to take answer a question we are asked regularly here. Can sharks stop swimming?

Most species of sharks are able to stop swimming, as they have developed ways to breathe whilst stationary. However, there are some species that must stay on the move constantly in order to breathe and stay alive.

Let’s take a closer look…

Can Sharks Actually Stop Swimming?

Sharks breathe by using their gills to extract oxygen from the water.

Many species of sharks have developed a method of breathing called “buccal pumping“, which is when the shark gulps water through its mouth and pushed water over its gills to breathe.

This allows the sharks to be stationary in the water and still breathe. However, some species of sharks do not have this ability and must keep moving for water to flow over their gills and breathe.

This means they need to stay on the move at all times, even when resting and sleeping, which is why there is so little information or studies on sharks sleeping.

These species of sharks are called ram ventilators, and they are required to keep moving with their mouths open so that water can pass through them and over their gills.

Which Sharks Can’t Stop Swimming?

Sharks that must stay on the move to survive are called “obligate ram ventilators“.

Below are some obligate ram ventilator sharks that must keep swimming to survive:

• Great White Shark
• Hammerhead Shark
• Mako Shark
• Whale Shark
• Salmon Shark
• Bull Shark
• Thresher Shark

These sharks need to keep moving with their mouths open so that water can pass through their mouths and over their gills.

There are only around two dozen of the 400 plus species of sharks that are obligate ram ventilators, with most species evolving to the buccal pumping breathing method.

When obligate ram ventilator sharks need to rest or sleep, they often find waters that have a steady current of rich-oxygen flowing water and position themselves swimming towards it.

They will slow their bodies down so they are gently swimming into the current, which allows them to take small naps to recharge their batteries.

Which Sharks Can Stop Swimming?

Most species of shark are able to stop swimming and even rest on the bottom if they please. They move water over their gills by simply gulping.

Below are some of the many buccal pumping sharks that can stop swimming:

• Nurse Shark
• Angel Shark
• Carpet Sharks
• Tiger Sharks
• Bullhead Sharks

These sharks actively “inhale” water into the body by gulping, and forcing the water over their gills so that they can harvest the oxygen.

Some of these sharks even have prominent spiracles behind their eyes that allow them to pull in water even when they are buried in the sand.

Do Sharks Drown If They Stop Swimming?

Some species of sharks will starve themselves of oxygen if they stop swimming and essentially drown.

However, most shark species will not die if they stop swimming, as the combination of both buccal pumping and ram ventilation is most common in sharks.

Whilst most species will be 100% fine if they stop swimming, a few iconic species of shark will die if they stop swimming.

Do Sharks Sleep While Swimming?

The species of sharks that are required to keep swimming, obligate ram ventilators also sleep whilst they are moving.

They find strong currents in times when their prey are least active, often at night, and position themselves facing into the current.

They wind down and switch half of their brains off whilst the other remains active, allowing them to keep one eye open and be aware of their presence.

Sharks that need to keep swimming never really shut off completely, as these predators need to be aware of their surroundings at all times.

It’s incredibly difficult to find information or footage of obligate ram ventilators sleeping, as it’s difficult to even tell if they are sleeping because they are still moving.

But not only that, because they only sleep for such short periods of time, often having small 20 – 30 minute naps.

Final Thoughts

Can sharks stop swimming? Most species of sharks can, but there are around two dozen shark species that must remain on the move at all times.

These species of shark are required to move constantly as their only way of breathing is through ram ventilation.

This means they need to keep swimming with their mouths open so that water can pass through them and flow through their gills.

That said, many shark species have learned buccal pumping, which is a form of breathing where the shark forces water over its gills by pumping water through their mouths.

This allows some species to be able to stop swimming, and even remain stationary on the seafloor and buried in the sand.

Hopefully, this post has been helpful and you’ve learned something new today about sharks and why some can and why some can’t stop swimming.

Thanks for taking the time to read this post and feel free to share it with others who may find it valuable.