Chew on This!

Shark Week 2021: 7 weird facts to sink your teeth into

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These beasts of the sea are more than their teeth. Sharks come in a variety of sizes and live all over the world — and some have evolved to have surprising and unique traits.

Here are 8 shark facts that’ll sharpen your knowledge of the ocean’s iconic predators:

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7. They can jump

You’ve probably seen whales do this — but a few species of sharks can also breach the water and launch themselves into the air.

Bren Whelan, www.DonegalClimbing.ie, 2017

Youen Jacob

Great White sharks are known to do this, but Basking sharks jump too. They live off the coast of Ireland and Scotland.

6. They have scales

Yep, just like other fish. But in the shark world, they’re known as dermal denticles, which translates to small skin teeth.

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Clouds Hill Imaging Ltd./Corbis Documentary/Getty Images

While the fossil record is dominated by shark teeth, remains of the animal’s skin can also help researchers learn more about shark ancestors.

5. They don’t have tongues

Instead, some species likely use their shoulders to move food into their digestive system.

Jason Ramsay

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Bamboo sharks use suction to slurp up prey from small crevices.

But it wasn’t until 2017 that researchers demonstrated that the suction power comes from shrugging their shoulders back to draw the food further into the body.

4. Magnetic fields help them navigate

Some species are known to migrate thousands of miles, thanks to guidance from the poles.

Bryan Keller

Gerard Soury/The Image Bank/Getty Images

A 2021 study helped illustrate this phenomenon by demonstrating that migratory bonnethead sharks change their swimming patterns when exposed to different magnetic fields.

Here’s what that looks like in a small pool:

3. Deep-sea sharks are buoyant

It sounds counterintuitive, but the sharks that live at the depths of the ocean have to swim against their body’s natural inclination to float to the surface.

Mark Royer, University of Hawaii

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Researchers say this could give deep-sea dwellers a stealthy advantage — allowing them to float up without much effort — while hunting prey that normally lives above them in the water.

2. Some glow in the dark

The bio-fluorescent chain catshark prefers to live at the bottom of the ocean, where it turns a vibrant, deep green.

David Gruber

David Gruber / iScience

A 2019 study in iScience found that a group of small-molecule metabolites are responsible for this distinct hue.

1. It’s getting too hot for baby sharks to survive

As embryos develop, they rely on their yolk sacs for nutrition. But warmer waters lead to faster development, and in turn an earlier hatch.

M. Johnson

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A study on baby epaulette sharks found they are often born weak and undernourished. Only time will tell what effect climate change will have — and how long some species will be able to survive in the wild.

Read more stories about science here.