In a world-first, marine researchers in New Zealand have recorded rig sharks (Mustelus lenticulatus) producing clicking noises underwater. Their study documenting this remarkable behaviour by the small, bottom-dwelling shark, found around New Zealand’s coast, is making waves in the scientific community.

What's All the Clicking About?

Unlike many fish that use swim bladders to make sounds, sharks don't have that option. So how are these clicks happening?

According to the study, published in Royal Society Open Science, it looks like rig sharks may be snapping their flat, interlocking teeth together to produce the sounds. These teeth are usually used for crunching crabs and shellfish—but now they seem to serve a second purpose.

What Do the Clicks Sound Like?

Researchers described the sounds as short, sharp clicks, each lasting just under a twentieth of a second. The clicks ranged in pitch from 2.4 to 18.5 kilohertz—high enough that some fall outside human hearing—and reached volumes of up to 156 decibels, about as loud as a balloon pop!

Why Do Sharks Click?

The clicks were mostly heard when the sharks were being handled by researchers, usually within the first few seconds. That leads scientists to believe the clicks are likely a stress response or defensive reaction—a sort of underwater “back off!” warning.

There’s no clear evidence yet that the clicks are used for communication between sharks, but it opens up fascinating new questions about what else might be going on beneath the surface.

What It Means for Divers

For divers, this discovery adds another layer of mystery and wonder to the underwater world. It’s a reminder that sharks aren’t just silent predators—they may have more ways of interacting with their environment than we ever imagined.

And who knows? Maybe one day, you’ll hear a rig shark click in the distance—proof that the sea still has plenty of secrets left to share.