Phocoenoides dalli

LENGTH Up to 2.2 m / 7 ft

DORSAL FIN Triangular with white trailing edge

APPEARANCE Black, with large white flanks; small hump on back before tail flukes

BEHAVIOUR Usually in groups of 2–10; creates “rooster-tail” of spray when swimming quickly

Photos by J. Ford and A. Morton. Illustrations by A. Denbigh, not to scale.