A newly named shark walks across Papua New Guinea’s shallows on its fins, and it may already be at risk

Scientists have formally named a small reef shark that moves across the seafloor by pushing itself along on its paddle-like fins, an unusual way of getting around that has earned its relatives the nickname of walking sharks. The species lives in the warm, shallow waters off Papua New Guinea, and researchers who described it warn that its tiny geographic range may leave it vulnerable to extinction. The naming turns a poorly known reef dweller into a documented species that conservationers can now track and protect.

How a shark learns to walk

The animal belongs to a group sometimes called epaulette or walking sharks, small bottom-dwelling fish rarely more than a meter long. Rather than swimming continuously, they clamber over coral and sand by flexing their muscular pectoral and pelvic fins, a rolling gait that lets them wedge into crevices and pick through reef nooks in search of food.

That behavior is more than a curiosity. Moving along the bottom on its fins lets the shark hunt in tight spaces and, in some relatives, survive in tide pools where oxygen runs low. Because these sharks stay close to a single reef system throughout their lives, populations tend to be isolated, and new, narrowly distributed species keep turning up as researchers survey remote coastlines.

A new species out of Milne Bay

The newly recognized shark was described from specimens collected in the seas around Papua New Guinea, a stretch of coral-rich water that sits within the biologically dense Coral Triangle. Distinguishing one walking shark from another takes careful work, because the species look broadly similar and differ mainly in the pattern of spots and blotches across the body and in fine details of anatomy.

According to the researchers who published the description, the animal’s markings and features set it apart clearly enough to warrant recognition as a species in its own right. Formal naming matters for conservation: an animal that has no scientific name is difficult to list, assess or defend against threats, so the description is a first step toward any protection.

Why a small range is a large problem

The same trait that produces so many walking shark species also puts them in danger. Because each one tends to occupy only a small area, a single event, a bleaching episode, coastal development or intensive fishing, can affect a large share of its entire population at once. Sharks that range across whole oceans can absorb local losses; a species confined to a few reefs cannot.

Researchers who studied the newly named shark suspect it may already be at risk of extinction, precisely because its known distribution is so limited. That concern is a warning rather than a verdict, since a full assessment requires more surveys, but it underscores how fragile a narrowly distributed animal can be.

Life inside the Coral Triangle

The waters around Papua New Guinea sit at the heart of the Coral Triangle, a region that holds a greater variety of coral and reef life than anywhere else on Earth. That richness makes it a hotspot for new discoveries, and walking sharks are among the groups that have diversified there into many closely related forms.

Warm, shallow reef flats give these sharks the terrain they need, low walls of coral to clamber over and abundant small prey such as crustaceans and worms buried in the sand. But those same shallow, near-shore habitats are the ones most exposed to warming seas, pollution and human activity, which places the region’s specialized animals under mounting pressure.

Turning a discovery into protection

Naming a species is where conservation work begins, not where it ends. With a formal description in hand, biologists can push for surveys to map how widely the shark actually ranges, estimate how many remain and identify the threats that matter most. Only then can it be evaluated for a conservation listing that carries legal or management weight.

For a bottom-dwelling reef shark that spends its life within a small patch of ocean, the stakes of that follow-up are high. The description gives scientists the tool they lacked, a recognized name and a clear set of distinguishing features, to argue that a little-known walker across the shallows deserves attention before its numbers slip away unnoticed.

Sharks that survive where others cannot

Walking sharks belong to a lineage remarkable for its toughness as well as its unusual gait. Some relatives can tolerate water with very little oxygen, weathering conditions on reef flats at low tide that would kill many fish, by slowing their bodies and even withstanding brief periods of near-suffocation. That resilience helps explain how such small, non-migratory animals persist in shallow, variable habitats.

Yet endurance in the face of natural stress does not translate into safety from human pressures. An animal adapted to survive a harsh tide pool has no defense against a reef bulldozed for development or stripped by destructive fishing. The newly named shark’s hardiness against nature only sharpens the concern that the threats now looming over it are of a kind evolution never prepared it to face.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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