Let’s learn about sharks

These fish have super-sniffing noses and can detect electrical signals from their dinners

These are hammerhead sharks off the coast of the Galapagos Islands. Sharks have lived on Earth for millions of years and take a wide variety of forms.

Janos/iStock/Getty Images Plus

Many films and TV shows will tell you that sharks are scary, here to snap up beachgoers. But that’s simply not true. Sharks fill an important niche — or ecological role — in the ocean.

Many of these fish are top predators that control populations of other animals. Other sharks serve as clean-up crews, chowing down on migratory birds when they fall out of the sky. But not all sharks are carnivores. Some, like the whale shark, are peaceful plankton eaters.

As a group, sharks are much, much older than we are. The first shark-like fish appeared more than 400 million years ago. Since then, they’ve taken on a wide variety of forms. Some have sawfish-blade noses, and extinct species may have had big hooks on their heads.

Sharks also have a lot of fascinating talents. They have super-sensitive noses and use snouts full of goo to detect faint electrical signals from their prey. Scientists are even trying to design materials to mimic sharks’ bacteria-battling skin.

Want to know more? We’ve got some stories to get you started:

Tiger sharks feast when migratory birds fall out of the sky: Migrating land-based birds that fall from the sky as they cross the Gulf of Mexico can end up in the belly of a young tiger shark. (6/12/2019) Readability: 7.3

Electricity sensor harnesses a shark’s secret weapon: A new “quantum” material mimics the sensors that help a shark sense its prey. Like a shark, it can detect tiny electric fields. (4/17/2018) Readability: 7.3

Snout goo may help sharks sense prey: Scientists may be one step closer to understanding how sharks sense their prey. Pores on their snout and face are lined with a gel that may help relay electrical currents created by prey’s movements. (6/30/2016) Readability: 6.3

Many people are afraid of sharks. But the world would not be better without them! Here’s why.

Explore more

Scientists Say: Niche

Explainer: How a fossil forms

These sharks get help swallowing from their shoulders

What ‘The Meg’ doesn’t quite get right about megalodon sharks

Traces from nuclear-weapons tests offer clues to whale sharks’ ages

Attack of the inner-cannibal mega-shark

Repelling germs with ‘sharkskin’

How sharks survived the ‘Great Dying’

Word find

Sharks have very big, oily livers. The oil in their livers actually helps them float. That’s because oil is slightly less dense than water. You can test this yourself with a simple experiment, no sharks required. All you need is some oil, balloons, toilet paper tubes and a bathtub.

Bethany Brookshire was a longtime staff writer at Science News for Students. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

More Stories from Science News for Students on Animals