Can Fish Swim Backwards?

With such a wide variety of different fish species, it may come as no surprise that there is an equal diversity in swim patterns and abilities for fish. However, can fish swim backward?

To learn the answer to that, as well as other questions such as “Can fish walk,” keep reading below. Ready to find out if fish can swim backward? Let’s dive!

Can Fish Swim Backward?

To provide an overall, short answer: fish can swim backward. However, not every fish can swim backward, and even those that can not do so in the same way.

Most fish use their fins to swim backward. This involves an increased amount of energy, though, so you probably won’t see fish do this often. Instead, it is often best used as an additional strategy to escape high-tension situations, such as those against rivals or predators, or to catch prey.

What Fish Can’t Swim Backward, and Why?

Believe it or not, there is only one group of species in the ocean that are unable to swim backward. As it turns out, despite being one of the most successful predators in the ocean, sharks actually lack the ability to swim backward like other species of fish. 

In order to successfully breathe underwater, the majority of shark species must constantly swim forward. They are unable to stop or turn around, as this will allow water to fill their gills rather than move through them, essentially drowning the shark. 

This isn’t to say that sharks don’t excel in other swimming aspects. For instance, their unique cartilaginous body allows them to quickly move up or down the water column with little to no consequences. Fish with swim bladders may struggle with this action.

Can Fish Walk?

Now that you know which fish can and can’t swim backward, you may be wondering about the additional locomotive methods of aquatic life. This includes whether or not fish can walk. While it may seem a little silly to think about a fish walking around on dry land as humans do, many species of fish, including sharks, do have the ability to “walk.”  

Take a look at the Australian epaulette sharks. These sharks live in shallow waters, and rather than swimming, they can use their pectoral and pelvic fins to move across the ocean floor.

There are also the handfish and frogfish, two families of anglerfish that are also able to walk along the sea floor. However, it’s important to note that, like with the epaulette sharks, this isn’t the same type of walking as terrestrial animals.

Can Fish Stop Suddenly While Swimming?

Just like swimming backward, the majority of fish species can stop swimming suddenly. However, as before, some species of sharks may struggle with this. Just as swimming in reverse can allow water to fill the gills of the shark and drown them, so can stopping. 

This isn’t true for all shark species, however. Some sharks are able to pump water to receive oxygen manually. This is known as buccal pumping, and it involves certain species of sharks drawing in water using their cheek muscles to allow it to move over the gills in a safe way. Only some sharks are able to do this, such as nurse sharks, which allows them to remain stationary for periods of time.

Can Fish Turn Around?

If you’ve ever had the chance to watch a group of schooling fish, then you may have seen them turn around or swim in circles. While fish may not have the same ability to turn around as we do (that is, standing in the same spot while changing orientation), they are able to turn and go in the opposite direction. 

The ability to turn around is essential. It allows fish to quickly catch prey, avoid predators, and excel in schooling mechanisms. 

How Do Fish Sleep?

Before learning how fish sleep, it’s important to understand that fish don’t sleep the same way that mammals do. When humans sleep, we enter a deep state of unconsciousness where, most likely, we aren’t alert to what’s going on around us. Dogs and cats may also sleep in this way, though they often remain more alert to their surroundings than humans.

However, fish don’t sleep in this traditional sense. Instead, they rest by reducing their activity level while still maintaining an awareness of any nearby danger. Some fish will float while they sleep, while others may utilize crevices in rocks and coral structures to keep from drifting off while they drift off.

This all works because fish can use half their brain at once. As a result, in order to sleep, half of the brain sleeps while the other half focuses solely on maintaining the life of the fish. This is known as unihemispheric sleep. 

Of course, this isn’t the rule with so many different species of fish. Some species of fish will utilize traditional sleep patterns to rest. The best way to learn about the sleep patterns and locomotion of a certain fish is to further research that species.

The photo featured at the top of this post is © Shaun Robinson/Shutterstock.com