Lemon Shark in black and white

Sharks

A rig shark
A rig shark (mustelus lenticulatus) (Arnim Littek, CC BY 4.0)

Clicks from the Deep: Scientists Record First-Ever Shark Sounds

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?

Frightened shark
AI illustration of a frightened shark

When Sharks Defend Themselves

A new study, led by Dr Eric E. G. Clua, has analysed decades of shark bite incidents in French Polynesia and found that certain human activities—especially spearfishing and handling fish traps—can trigger defensive bites from sharks. These bites are different from predatory attacks in that they result from a situation in which the shark feels threatened, often after a human has behaved aggressively towards it, whether intentionally or not.

Gray reef shark (Carcharhinus amblyrhynchos)

Some Sharks May Bite in Self-Defense Rather Than Aggression

Shark attacks are often sensationalized, reinforcing the perception of sharks as mindless predators. However, new research conducted in French Polynesia indicates that a small number of shark bites may be defensive reactions triggered by human behavior perceived as threatening. These findings challenge long-standing assumptions about shark motivations and call for a shift in how such incidents are interpreted.

Octopus Is Spotted Riding a Shark

The moment, captured on video by researchers from the Auckland University of Technology, has quickly attracted international attention.

While octopuses are known for their intelligence and problem-solving abilities, such behaviour is highly unusual. Researchers suggest the octopus may have been using the shark as cover, attempting to avoid predators or navigate more efficiently through the water. It is also possible the octopus was defending itself after an attempted predation by the shark.

Diagram showing Megalodon compared with other sharks
Diagram showing Megalodon compared with other sharks (Kenshu Shimada et al./ CC BY 4.0)

New Study: Megalodon Looked Like a Lemon

Megalodon, the largest great predatory shark to have ever lived, dominated the oceans millions of years ago during the Neogene period. Despite its fame, much about its appearance and biology remains a mystery since its skeletons, made mostly of cartilage, are rarely fossilised. However, this new research offers valuable clues.

Megalodon showing scale
Megalodon's size (EvolutionIncarnate / CC0)

Insights Into Megalodon Sharks' Behaviour

Sharks have long been the subject of fascination for scientists and enthusiasts alike and observations in the wild have revealed that their behaviour is far more complex than was previously assumed. But though the fossil record has provided a wealth of information about their prehistoric existence, it has rarely shown anything about their behaviour. 

Brain tissue from a stranded shark has been sent to the Washington Animal Disease Diagnostic Laboratory for genetic sequencing, which may reveal the virus or bacteria behind the meningoencephalitis. (Illustration: Peter Symes / AI)

Great White Sharks Dying From Brain Disease

Marine biologists are investigating unexplained deaths among great white sharks along the Atlantic coastline of the United States and Canada. Since 2022, at least nine carcasses have washed ashore, with necropsies revealing a common factor: meningoencephalitis, an inflammation of the brain and its surrounding tissues.

The great hammerhead shark (Sphyrna mokarran) is listed as endangered by the International Union for the Conservation of Nature

NSW protects threatened hammerheads

In response to scientific and community concerns, the NSW Government has listed the great hammerhead as vulnerable and the scalloped hammerhead as endangered under the Fisheries Management Act 1994.

"Formally recognizing that these two shark species are threatened is a significant step forward to protect some of our most vulnerable marine wildlife. We congratulate the NSW Government for taking a proactive approach to conserving these magnificent sharks, which are swimming against the tide of extinction," said Tooni Mahto, AMCS Marine Campaigns Officer.