Movies like Jaws and Sharknado often give us the impression that sharks are savage, brainless hunters. But we thought it was time to set the record straight: They’re not.
Discovery’s Shark Week is in full swing, so we thought there was no better time to clear up some of the misinformation surrounding these incredible undersea predators. Because the reality is, they have a lot more in common with humans than brainless killers.
Humans and sharks are actually distant cousins
It might be hard to believe, but humans are actually related to sharks. While evolution hid away most of the evidence, some traces still remain. The elephant shark’s genome, for example, is so similar to humans’ that we have more in common with it than other fish that previously ranked closer to us in the evolutionary tree. That because, at some point 450 million years ago, humans and sharks shared a common ancestor. Which means we’re all basically mermaids…dangerous mermaids.
Sharks can make friends and form long-term relationships
It’s tough to imagine a shark being friendly to anything, but they’re no strangers to complex relationships. A scientist at the Center for Island Research and Environmental Study was researching blacktip reef sharks when she noticed many of them worked together to herd a school a fish. Johann Mourier also noticed that sharks of the same sex and relative size would stick together, possibly for protection and to avoid the aggression of other sharks. We can only imagine what their arguments are like!
Sharks get tired after getting funky
According to the Safina Centre, when two sharks begin getting it on, the pair stops swimming and begins to sink, eventually coming to a rest on the sea floor. For many species, this impacts their ability to breathe properly (sharks need to swim in order to breathe). So when the lovers finally disengage, both the male and female take a second to rapidly ventilate to repay that oxygen debt. Sound familiar?
They can “freeze” their eggs
Nope, not lying. Except, unlike humans, sharks don’t need the help of a fertility clinic. Some sharks can actually store both sperm and eggs inside their bodies until they are ready to fertilize them, just as humans are able to freeze and store theirs in a lab. The current record goes to a brownbanded bamboo shark, after she held onto sperm for a whopping four years before finally using it. Scientists are still unsure exactly how sharks determine when that special time is though.
Have we mentioned they can be trained?
Just like humans get training for a new job, sharks can be trained to do things like cuddle. Yes, cuddle. In an experiment in the U.S., sharks at an aquarium were trained to associate certain colours and sounds with dinner time (as part of an effort to avoid a feeding frenzy). Keepers would hold a “target stick” with a colour on it whilst playing a sound. Then, a shark that has been trained to respond to that colour/noise would touch its nose to the sign and wait to be fed. Some sharks have even used the opportunity to roll over and have their bellies scratched! So much for vicious animals, eh?
Sharks think like humans
At least, in some ways. Up until now, most experts have believed that sharks are somewhat unintelligent and use their mouths to get a better sense of their environment. But they’re starting to realize sharks are actually quite reliant on their eyes. In the case of great white sharks, for example, the area of the brain that receives visual imput is quite large, just like it is in humans. Shark prevention technology usually relies on non-visual cues to keep the apex predators at bay, but the new findings are expected to change that.
Human eyes and shark eyes are basically the same
Even if you’ve never seen a shark, you might have already looked into the eyes of one. Shark corneas have been successfully used for human corneal transplants, meaning somewhere out there, someone has a pair of shark eyes. You can credit that to the fact that shark corneas don’t swell, and human tissue won’t reject them (maybe because we’re related?).
Don’t forget, Discovery Canada’s Shark Week airs from July 5 to 12.