Description & Behavior
Ginko-toothed beaked whales, Mesoplodon ginkgodens (Nishiwaki and Kamiya, 1958), are a type of beaked whale where the adult males have been observed with darkly colored with white spots over the posterior (rear) 1/3 of their undersides. These white spots may be pigmentation or parasitic scars. Females are believed to have medium gray bodies with light gray undersides. Males are characterized by a single pair of slightly protruding lower teeth (called tusks) that are shaped like a ginkgo leaf. They do not appear to be as heavily scarred as most other mesoplodonts. Their throat grooves, dorsal fins, and tail flukes are typical for Mesoplodon species. Ginko-toothed beaked whales’ maximum known sizes are 4.9 m (females) and 4.8 m (males).
Beaked Whales (Family Hyperoodontidae)
These medium-sized to moderately large whales have a single pair of grooves on their throats. They have a distinct snout, and often the few teeth present are visible only in adult males. They have a single nostril or blowhole. Beaked whales are generally slender with small dorsal fins toward the rear on their backs. The rear edge of their flukes (tails) usually lack a well-defined notch. These whales are deep divers and are rarely seen. Many species are known only from a few specimens, and little is known about the life history and biology of the group. All members of this family, except Blainville’s beaked whales, are difficult to distinguish from each other, and study by museum experts is usually necessary for identification.
World Range & Habitat
Ginko-toothed beaked whales, Mesoplodon ginkgodens, are found in the North Pacific from Japan to California, and have also been sighted in the Indian Ocean. They have been found stranded off the coasts of Japan, California, Mexico, Taiwan, Indonesia and Sri Lanka. Because of the rare sightings, it is thought that this species prefers warm, offshore open waters.
Feeding Behavior (Ecology)
Almost nothing is currently known of the biology of ginko-toothed beaked whales. At birth, they are thought to be about 2-2.5 m.
Conservation Status & Comments
A few animals have been taken in coastal fisheries off Japan.
References & Further Research
Center for Cetacean Research and Conservation (CCRC) – Beaked whales (+ videos)
Jefferson, T.A., S. Leatherwood, and M.A. Webber, FAO species identification guide, Marine mammals of the world, Rome, FAO. 1993. 320 p. 587 figs.
Research Mesoplodon ginkgodens @
Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS