The sand tiger shark is the only shark that gulps air to float motionless.

Nature · Published 3 October 2026 Swipe more like this →

In short: With a mouthful of jagged, protruding teeth, the sand tiger shark looks like a nightmare. Yet, this docile predator is famous for a strange, buoyant trick: it gulps air at the surface and stores it in its stomach, allowing it to hover effortlessly while hunting in the dark.

Despite its fearsome appearance, the sand tiger shark (Carcharias taurus) is a relatively placid, slow-moving creature. It is known for a unique physiological habit: it is the only shark species that surfaces to gulp air. By storing this air in its stomach, the shark achieves neutral buoyancy, enabling it to remain perfectly still in the water column while waiting for prey. This energy-efficient strategy allows it to hunt effectively at night, often trolling just above the ocean floor in shallow, coastal waters.

The shark’s name is somewhat misleading. While the 'sand' refers to its preference for shoreline habitats, the 'tiger' was inspired by its large appetite rather than any relation to the actual tiger shark. In fact, the species is not closely related to either tiger or nurse sharks. Its physical profile is distinct, featuring a brownish-gray body often marked with darker, rust-colored spots and a whitish belly. Its teeth are so long and jagged that they remain visible even when the shark’s mouth is completely closed.

Though they appear aggressive, these sharks are generally non-confrontational toward humans, typically only reacting if they are bothered first. They are highly valued in public aquariums for their impressive look and their ability to thrive in captivity. However, in the wild, they face significant conservation challenges. They possess one of the lowest reproduction rates of all shark species, making them highly susceptible to population pressure. Consequently, they are listed as vulnerable and are protected throughout much of their global range, which spans temperate and subtropical waters from Japan and Australia to the coasts of North and South America.

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