A recent study published in the Royal Society Open Science journal has revealed that sharks are capable of producing a series of clicking noises, marking the first known sounds made by these creatures.

Led by marine biologist Carolin Nieder from the Woods Hole Oceanographic Institution, the research focused on the rig shark, or spotted estuary smooth-hound, commonly found in New Zealand's coastal waters.

This small species plays a vital role in the local commercial fishing industry and can grow between 70 to 150 centimeters.

The clicking sounds, which can reach volumes comparable to a gunshot or firecracker, were primarily observed during handling, suggesting they may be a distress response.

Interestingly, about 70% of the clicks occurred alongside calm body movements, while 25% coincided with vigorous thrashing, and 5% occurred when the shark was still.

The absence of clicking during feeding or swimming led scientists to hypothesize that these sounds might serve as a defense mechanism or stress response.

Nieder proposed that the clicks could function as a startle response to threats from larger predators, although further research is needed to understand their context in the wild.

It remains unclear whether rigs can hear the sounds they produce; if they can, it may indicate a form of communication, while if they cannot, the clicks might simply be a reaction to stress.

The clicking sounds, averaging about nine clicks in a 20-second span, are believed to result from the clacking of their flattened teeth, which are adapted for cracking crustacean shells.

This study adds to a growing body of evidence that some cartilaginous fish, including rays and skates, produce sounds, suggesting that sound production may be an ancient trait among these species.

Neil Hammerschlag, president of Atlantic Shark Expeditions, noted that this research raises new questions about shark communication and behavior, emphasizing the need for further exploration.

Nieder plans to conduct additional behavioral experiments to investigate the triggers for the clicks and explore other shark species in their natural environments.