Nishiwaki & Kamiya, 1958 - Ginkgo-toothed beaked whale
Distinctive Characteristics
Adult male ginkgo-toothed beaked whales are dark grey, with light spots; females are apparently lighter. They do not appear to be as heavily scarred as most other mesoplodonts. The throat grooves, dorsal fin, and tail flukes are typical for Mesoplodon species.
Bulls have flattened tusks that barely break the gumline, slightly behind the middle of the lower jaw; erupted teeth are absent in females.
Can be confused with
The uniform dark pigmentation, small posteriorly placed teeth, and paucity of characteristic ziphiid scars may allow a tentative classification of adult male ginkgo-toothed beaked whales. Otherwise, this species will be virtually indistinguishable from other species of Mesoplodon.
Size
Maximum known sizes are 4.9 m (females) and 4.8 m (males). At birth, they are thought to be about 2 to 2.5 m.
Geographical Distribution
This species is known from widely scattered sightings, strandings, and collections (albeit sparse) in temperate and tropical waters of the Indo-Pacific Ocean.
Biology and Behaviour
Almost nothing is known of the biology of the ginkgo-toothed beaked whale.
Exploitation
A few animals have been taken in coastal fisheries off Japan.
IUCN Status
Insufficiently known.