Common Name: Ginkgo-Toothed Beaked Whale
|Ginkgo-Toothed Beaked Whale|
Size comparison against an average human
(Nishiwaki and Kamiya,1958)
Ginkgo-Toothed Beaked Whale range.
General Description: The Ginkgo-toothed Beaked Whale (also called the Japanese Beaked Whale) has a distinct beak and lacks teeth in the upper jaw. It has no notch in the middle of the tail flukes, and in common with all beaked whales, has two V-shaped grooves under the throat. The fin is small and the flippers are short and narrow.
The head of the whale is distinctive. A flap of skin from the rear half of the lower jaw almost envelopes the enormous teeth. The upper jaw is very narrow with a sharp point.
The colour, based on dead specimens, is described as dark grey, blue-grey or black on the back, lightening to pale grey on the belly. The skin turns black very rapidly when the whale dies. Many oval white scars are found on the flanks and belly.
Size: The maximum length attained by the Ginkgo-toothed Beaked Whale is believed to be about 5 m. Its weight has been variously estimated as 1.5 and 3.6 tons.
Appearance At Sea: The Ginkgo-toothed Beaked Whale is relatively rare. Not much is known about its behavior.
Found In: The habitat of Ginkgo-toothed Beaked Whales is not known. Fish and squid are apparently the main food of this species.
Records from India: The species may inhabit the waters around India, as there is one stranding record from Sri Lanka, and another animal caught off Trincomalee is suspected to be a Ginkgo-toothed Whale. The stranded animal, washed ashore at Ratmalana near Colombo, was only the second specimen known of this species, which was described from a specimen stranded in 1957 near Tokyo.
World Distribution: The Ginkgo-toothed Beaked Whale appears to inhabit the warm waters of the Indo-Pacific from Sri Lanka, through Japan across to California. It is reported to be hunted in Taiwan.
Could Be Confused With:The Ginkgo-toothed Beaked Whale can be distinguished from the Goosebeak Whale Ziphius cavirostris, another predominantly tropical whale, based on its distinctive head. Also, the Goosebeak Whale occurs in larger groups, has a tendency to lift its tail on diving and is larger in size.
The Ginkgo-toothed Beaked Whale can be distinguished from the Dense Beaked Whale Mesoplodon densirostris based on its pointed jaw, despite the fleshy flanges arising from the mandible.
Diagnostic Features: At sea, Pointed jaw, distinct beak.
Stranded Specimens:The adult male has one pair of large teeth about two-thirds towards the front of the lower jaw. The teeth are described as shaped exactly like the leaf of the sacred ginkgo tree. The shape has also been compared to that of an onion. The teeth are as broad as they are high, and have pointed tips. The base of the tooth may be 10 cm or more broad. These teeth are almost enveloped by a flap of skin from the rear half of the lower jaw.