Have you ever seen a shark throw it in reverse and back it up? No… me neither.
These apex predators of the deep seem to be driven with bloodthirsty instincts in one direction — Forward!
But does this mean these killer fish are physically incapable of swimming backwards, or is it just something they can do but would rather not?
To change direction, sharks seem to simply nose that why whilst maintaining their forward momentum, so do they ever need to head straight backwards?
It’s not like the oceans are so busy that they’re working with tight spaces all that often, so what’s really going on here? Let’s find out!
Can Sharks Swim Backwards Or Not?
The reason we’ve never witnessed a shark hit the brakes and swim backwards is that they can’t!
That’s right folks — sharks are completely, utterly, and hopelessly incapable of swimming in reverse; it’s just not an option for them.
In light of this, don’t expect to see one doing the backstroke anytime soon.
So, there’s our answer right off the bat, but if you’re interested in learning a little bit about why sharks can’t swim with backward momentum, read on!
What Prevents A Shark From Swimming Backwards?
There are actually a few reasons why sharks don’t swim backwards, but there’s only one reason why they can’t swim backwards, and that’s simply that their pectoral fins weren’t designed to curve upwards, which is critical to building reverse momentum.
You can almost think of them like an airplane — Every physical aspect of their bodies is designed to have molecules flow into them head-on, front to back.
Their fins can only facilitate this kind of interaction with the water that surrounds them.
Another directionally limiting aspect of their physiology is that they have large rear tails, tails that aren’t flexible enough to curve around and flap in the other direction.
Sharks also don’t need to travel backwards, as it’s their lightning-fast forward motion that makes them such devastatingly effective carnivores.
Believe it or not, most fish can actually swim backwards.
It helps them navigate the tight squeezes in which they often hide or find food, but it’s also a remarkably slow movement.
Sharks, on the other hand, do not have to hide… ever, nor do they hunt for food in tight spots. They storm head first into unsuspecting sea creatures in the open ocean.
Now for the tragic reason sharks wouldn’t swim backwards even if they could… they’d die!
Remember when you were a kid and you stuck your head out the car window for cheap thrills, and you couldn’t breathe despite the oxygen slamming into your gaping mouth at 50 miles per hour?
Well, this is kind of the same thing that would happen to sharks if they changed their mind one day and decided it was time to start moving in reverse.
The gills are angled towards their rear, which means while swimming backwards, water would rush into them, disrupting their breathing until they eventually suffocated.
Do All Sharks Swim In The Same Way?
There are 500 different species of sharks on the hunt in the deep blue right now, so it should come as no surprise that many have unique ways of getting from pelagic-A to oceanic-B, yet they have all evolved in more or less the same ways.
Over millions of years, these toothy torpedoes become incredibly streamlined in order to hasten their movement through water and improve their agility within it.
Still, variation in motion spans from cruisers to floaters, to wrigglers, to flappers.
Each swimming style is a little different, but the core of each one is the wiggling of that rear caudal fin.
For the most part, sharks use their tail to propel themselves forward through water, while their fins are like little rudders used for balancing and turning.
Being that all sharks share this core thrust generator, regardless of their swimming style, they can only follow their noses.
Do Sharks Have An Advantage By Only Swimming Forward?
It’s not that sharks have a hunter’s advantage over prey and other sea creatures by never swimming backwards, but, as mentioned earlier, it does regulate their breathing and keep them alive and healthy.
Perhaps my sticking-your-head-out-the-car-window analogy from earlier was a little off the mark, as sharks don’t actually breathe in through their gills, but out.
Water flows in through their mouths, passes through to the inside of their gill system where the oxygen is filtered out of the water, and then the waste H2O is purged from their gills.
So if they were to suddenly start swimming backwards, it would essentially reverse their breathing system and kill them relatively quickly.
This is why fishing folk would often drag sharks backwards on their way back to the shore, as it would do their grisly job for them.
Is General Backwards Motion Out Of The Question For A Shark?
There are a couple of ways a shark may be able to safely move backwards… gravity and current.
Gravity may be scarce underwater, but it’s not completely absent, so if a shark was angled towards the surface and stopped swimming forward, it stands to reason that it would slowly drift backwards, towards the ocean floor.
If a shark stopped swimming in the face of a deep-ocean current, it may also be pushed backwards.
However, as the shark could start swimming at any point during these two scenarios, it’s unlikely that they’d incur serious harm.
There’s also one intriguing exception to the shark-wide ban on backwards travel, the Epaulette shark.
Also known as the “walking shark”, these fantastic creatures often choose to walk across the seafloor and reefs using its fins as legs.
And while the Epaulette shark is taking a stroll, it’s completely uninhibited; it can go any direction it pleases, including backwards.
While they do have a very high tolerance to oxygen-deprived waters, when it comes to swimming, this wandering shark is bound by the same directional laws as its bitey brethren.
What Happens When Sharks Swim Backwards?
Again, sharks won’t swim backwards, because they can’t, but if they could, they’d avoid it at all costs, as it would invert their respiratory process and send them to the bottom of the ocean, most likely to be devoured by other sharks.
Can Sharks Stop For A Rest?
Okay, so we’ve established that sharks can’t swim backwards, but can they at least pump the brakes and have a moment of calm amidst their turbulent lives? Well… it depends.
Sharks can’t suddenly stop swimming after going hell for leather for the same reason they can’t swim backwards from stationary — they can’t form that crucial upward curve with their pectoral fins.
That said, some are capable of stopping when already moving at a slow pace… allow me to elaborate.
Will A Shark Die If It Stops Swimming?
There are certain shark species, including but not limited to nurse sharks and reef sharks, that can come to a complete halt on the seafloor and still breathe due to buccal pumping.
Buccal pumping happens when the buccal mouth muscle pumps water through to the gills without the aid of forward motion.
For sharks without this ability (usually the more prolific swimmers, such as the great white shark), stopping for long is not an option, as there will be no force to carry oxygen-rich water through to the gills.
What About The Red Tailed Shark?
The red tailed shark can indeed swim backwards, but before you start yelling at your computer screen and calling me a charlatan for claiming the opposite for this entire post, you should know that, despite the name, red tailed sharks aren’t sharks.
The dorsal fin gives them a striking resemblance to the meanies of the sea, but it’s just a cosmetic similarity that has nothing to do with their classification.
Red tailed sharks are actually categorized under the same umbrella as minnows and carp.
Would I Drown A Shark If I Pulled It Backwards?
If you were brave and strong enough to drag a shark backwards through the water, you would indeed kill it, but “drown” is perhaps not the right terminology.
A more apt verb would be “suffocate”, as drowning implies that water has entered where it was not before, which isn’t the case when a shark is pulled backwards.
At the risk of flogging a dead horse shark, to summarize — no, sharks cannot swim backwards, and even if they could, they would likely suffocate as they can only process oxygen if the water is traveling in through their mouth and then out through their gills.