Researchers have found a dolphin that breathes using its mouth instead of its blowhole, a behavior never seen before.

Steve Dawson of the University of Otago in Dunedin, New Zealand, was studying Hector's dolphin (Cephalorhynchus hectori) — a recently discovered species that is endangered — off the coast of New Zealand when he and his colleagues observed one dolphin swimming up for air. The dolphin was even making a sucking sound as if it were drawing in breath. Adding to the oddness of the situation was that the dolphin's blowhole never seemed to open.

Remember that dolphins, despite spending their whole lives in water, need oxygen just like other mammals, and they get that air through their blowholes. As Dawson explained to New Scientist, this way of breathing is tricky for dolphins. Unlike most mammals, dolphins' digestive and respiratory tracks aren't connected, so this dolphin is likely shifting its larynx so it can take in air to its respiratory system.

Apart from a blocked or non-functioning blowhole, Dawson told New Scientist the dolphin is in fine shape. "It's in great condition and looks absolutely normal, except for this weird breathing behavior," he says. "Clearly it's a thing that works for the animal."