The Great Dall's porpoise is a small

The Great Dall's porpoise is a small, toothed whale found in the northern Pacific Ocean. It is the only species in the genus Phocoenoides, and is sometimes referred to as the "white-sided porpoise". It is dark gray on its back and sides, with a white belly and a distinctive white patch on its flank. The head is small and rounded, with prominent eyes and a short beak. The dorsal fin is large and triangular, and the tail flukes are wide and curved. Males reach lengths of up to 1.7 m (5.6 ft), while females can reach lengths of up to 1.9 m (6.2 ft).