When you think of sharks, you likely think of Jaws-esque monsters, or else the quite alarming great white shark (who, despite their deadly reputation, only actually kill between one and six people every year).

But the reality is that there are over 500 species of shark swimming through our oceans and waterways, with many of them adorably small – in fact, 100 of those shark species are under 60cm long, and you’re more likely to be injured by a piece of paper.

One species of shark you’ve likely never heard of is the Thresher shark.

And despite the fact that they can grow up to six meters in length, the thresher shark is another species that you needn’t worry about – unless you’re a fish, of course. In that case, you definitely should worry.

That’s because the thresher shark (Alopias vulpinus) has adapted in a very specific and quite ominous way.

If you take one look at a thresher shark, the first thing you’ll likely notice is their odd tails, which have developed into effective, machete-like whips for efficient hunting and even more efficient stunning of their prey, according to a recent study from researchers at Florida Atlantic University.

In their paper, which was recently published in the journal Royal Society Open Science, the researchers used micro-CT scanning of ten thresher sharks of various ages to understand exactly how their anatomy has developed to make them such effective hunters.

And their results show a predator that knows exactly what it wants, and has developed a very effective way of getting it.

According to the researchers, the unique vertebrae of the thresher shark is what allows them to whip their tails in such a unique way, with a catapult-like vertebral column that allows them to twist into impossible positions to hunt.

And as FAU researcher Marianne E. Porter explains in a statement, this fascinating adaptation helps these curious-looking sharks to fight for their survival within their marine ecosystem:

“We think that anterior body vertebrae stabilize the thresher shark’s main body, while vertebrae closer to the tail support overhead tail-whips. Additionally, developmental changes suggest that vertebral anatomy shifts across development to support a larger body and caudal fin.”

The good news is that thresher sharks aren’t interested in eating humans: in fact, they tend to be very timid when people are around.

As for mermaids? The jury is still out.

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