Ginkgo-toothed Beaked Whale

The ginkgo-toothed beaked whale is a poorly known beaked whale named for the unusual shape of its pair of teeth. It is fairly typical in appearance but notable for males having no scarring. Males are overall dark grey with light patches on the front of the beak and around the head, and small white spots under the tail; females are lighter grey with countershading (Wikipedia, general species account).

Its range is essentially tropical and temperate waters of the Indian and Pacific Oceans. It probably feeds mainly on squid. The whales are shy and wary of boats and spend almost all of their time foraging at depth, coming up for air for a few minutes before descending again. Its call has a distinct acoustic signature known as BW43. Its occurrence in Japanese waters is documented by the National Museum of Nature and Science marine-mammal database.