Sharks are the most maligned creatures on earth. For most of human history, no one cared about these animals until swimming began to grow in popularity. The odd shark attack put them on the radar, and then the movie Jaws sealed their fate. They were slaughtered by the thousands afterward. Nowadays up to 100 million are killed every year. And it’s a damn shame because sharks are amazing in ways that most people never realize.
10. Sharks Attack More During a Full Moon
According to PETA, a cork from a champagne bottle is more likely to kill you than a shark. Whether or not that’s entirely true, it is a fact that shark attacks are relatively rare, and far rarer than most people think. Only 10 people died from unprovoked shark attacks in 2020. That said, if you want to maximize your odds of not being in the net group of 10, choose the time you head into the ocean wisely.
It turns out that sharks are the werewolves of the sea. Attacks tend to happen more often during a full moon than other times of the month. The fuller the moon, the more the attacks. And that makes it seem like perhaps the moonlight is allowing sharks to see better and therefore attack more, except that the attacks generally happen during the daytime, it’s just that they coincide with these lunar phases.
We know that the moon has an obvious effect on the oceans with how the tides work, but clearly it’s angering up some sharks as well.
9. Some Sharks Glow in the Dark
Is a shark more or less intimidating if you can see it coming? There’s obviously something terrifying about something jumping out at you from nowhere, but what if you can see it approaching and just have no way to defend yourself? And with that in mind, would you be more or less scared of a shark that glows in the dark?
Bioluminescence is still something of a novelty to humans because, in the space we occupy, few animals are capable of glowing. In the sea, there are upwards of 1,500 species of fish that have the ability to generate light. These are generally deepwater fish, and they’re usually not sharks. But some of them are. In particular, three species discovered off the coast of New Zealand. One of them, the kitefin shark, grows to nearly six feet in length.
8. Several Shark Species Can Walk on Land
Whether their reputation is deserved or not, one thing most people could take solace in when it came to sharks was that they’d leave you alone if you left them alone. They live in the sea; we live on land. We never have to cross paths if we don’t want to. And then you find out that some sharks can walk on land.
Science has identified a handful of fish species that can actually walk on land. In 2020, four new species of walking shark were identified. And if you read about them, the story details how they can use their pectoral fins to walk across the sea floor and hunt prey that lives under rocks and in coral. And that seems cool because they’re walking but not “land” walking, right?
Of course, the epaulette shark is able to walk on land outside of the water, a feature that likely evolved to help it survive if it gets caught in shallows or in a pool when the tide goes out. They can stay out of the water for up to an hour.
7. Sharks Smell in Stereo
No doubt you have heard that a shark is able to sense electrical signals in the water, which is how it hunts. And if you think that’s to make up for poor eyesight, think again. Sharks have vision 10 times greater than humans. And if that wasn’t enough, their sense of smell is far more advanced than what a human has as well.
Sharks don’t just smell prey in the water, they smell it in stereo. When a shark is swimming and there’s injured prey in the water, the smell will hit one nostril before another. The shark will navigate by the timing of the smell that reaches it, so it will turn towards whichever nostril smelled the smell first. As they swim, moving their head through the smell, they pick which nostril is getting the most smell to direct their movements.
In highly concentrated areas of smell, say a pool of blood, they need to be able to distinguish which nostril is getting the highest concentration of smell and adjust their tack based on that. They can make these adjustments to their direction in mere seconds.
6. Venomous Sharks live in the Thames River
There are a lot of dangerous animals in the world, and they can be dangerous for different reasons. Things like bees and hornets attack in large groups. A cheetah is fast. A rattlesnake is venomous. And a shark has deadly jaws and speed in the water. But at least that’s all. Except for a couple of species of sharks that are actually venomous, too.
Turns out that being a shark just isn’t intimidating enough for a handful of species, including one that’s been found in the Thames River in England. Though the Thames was essentially a polluted trickle of death for many years, it’s been making a steady comeback lately and part of that has included signs of sharks known as spurdogs in the water. Spurdogs are just under two feet in length and have spines in front of their dorsal fins that can envenomate prey.
5. Cookie Cutter Sharks Disabled Nuclear Subs
Jaws made us afraid of Great White sharks but the real terror of the deep are cookiecutter sharks. They may only be 20 inches long, but these little beasts have a real horror movie side to them, which is basically their mouths. They get their name because that mouth allows them to bite nearly perfect circles out of their prey. And then some.
Turns out the sharks like to bite almost everything, including nuclear subs. Their tiny size and unique mouths meant that, back when nuclear subs were first taking to the water, any exposed non-metal parts were perfect prey for the sharks. They’d bite hoses and cables and whatever else they could reach. Their attacks on rubber sonar domes blinded subs and forced them to return to dock for repairs.
The subs were later designed with some stronger materials and the tiny sharks’ reign of terror was over, at least insofar as it related to nuclear weapons.
4. Sharks Were Discovered in an Active Underwater Volcano
The microscopic tardigrade is one of the most indestructible creatures in the world. They can survive mountaintops and the depths of the ocean, they can survive outer space and temperatures that range from -328 degrees to 300 degrees Fahrenheit. It seems like no environment is too extreme. And, as it happens, there are some sharks that have taken a page from the tardigrade’s book.
Near the Solomon Islands there’s an underwater volcano called Kavachi. It’s an active volcano, and it erupts frequently, spewing ash and lava and chemicals into the water. In 2015, when researchers went to investigate, it was not erupting at that time, but the water was still very hot and acidic. They sent down a camera and saw two species of shark living right in the caldera of the volcano.
Sharks are known to be able to endure deep water, so the water around the volcano is just another extreme. It’s believed that their ability to sense electromagnetic signals may help them survive by warning them before the volcano actually erupts so they can leave the area.
3. Sharks Like Jazz
There is an abundance of research that shows animals like music. Classical music causes cows to produce more milk. Elephants seem to like classical music as well. And sharks? Well, they respond to jazz.
Based on research that involved using food as a reward, researchers determined that sharks were more attracted to the sound of jazz music than something like classical. When they played jazz music, the sharks would swim towards it to get their food reward. When combined with classical the sharks got confused but cut them a break, they’re just fish.
The research is a nice complement to the idea that sharks tend to be attracted to certain sounds in water, in particular boat engines. People on boats chum the waters, in particular when they want to swim with sharks, so it shows sharks can learn to go towards certain sounds that might otherwise seem like they should offer nothing or even scare animals away.
2. Bull Sharks Can Live in Freshwater
Although Great White sharks get a lot of press because of movies like Jaws and the fact that they’re just kind of huge, they are not considered the most dangerous shark in the sea. That honor goes to bull sharks. Bull sharks are highly aggressive and are not afraid to protect their territory. Keep in mind there are not that many shark attacks from any species at all, but bull sharks are still one of the more aggressive species in the water. And the fact they’re not confined to saltwater makes them a little more intimidating.
Most sharks need to regulate the levels of salt in their body and that requires them to live in saltwater all the time. A great white shark in freshwater will die fairly quickly as its cells breakdown due to a lack of salt when their body essentially becomes diluted with freshwater. A bull shark, however, has adapted the ability to recycle salt in its own body through its kidneys and some tail glands that retain salt.
Bull sharks typically have their young in fresh or brackish water, which helps protect them from predators. Though they do head out to sea eventually, they are able to stay and thrive in freshwater.
1. Sharks Can Pushed Their Insides Right Out
Sharks are known as voracious eaters.A great white can sustain itself for around two weeks on 66 pounds of food. A whale shark will consume 46 pounds of plankton per day. Suffice it to say, sharks can eat. And not everything they consume is even food. Some have been caught with things as bizarre as wine bottles, drums, and even a cannonball in their stomachs.
Given how much goes into a shark, it seems reasonable that there has to be a way for it to get back out again. And there is, even if it’s not the way you’d think. Sharks have the ability to throw up in the most over the top way possible, by forcing their entire stomachs back out of their mouths.
The act is most often seen when sharks are under stress, from things like being caught by fishermen or being beached, for instance.
It’s believed that sharks do this not just out of stress, but also to essentially rinse out their stomachs. If they have a lot of foreign material or dangerous materials inside, they can dump it, rinse it in seawater, and suck it right back in. It takes only a moment for a shark to push its stomach out and then swallow it again, and they seem to be no worse for it once it’s done.