Ginkgo-toothed Beaked Whale
Encyclopedia
The ginkgo-toothed beaked whale (Mesoplodon ginkgodens) is a poorly known species of whale
even for a beaked whale
, and was named for the unusual shape of its dual teeth. It is a fairly typical-looking species, but is notable for the males not having any scarring.
and Andrews' beaked whale
, the teeth do not arch over the rostrum. The beak itself is of a moderate length. The coloration is overall dark gray on males with light patches on the front half of the beak and around the head, and small white spots on the bottom of the tail, but the location may be variable. Females are a lighter gray and have countershading. Both genders reach 4.9 meters (16 feet) in length. They are around 2.4 meters long (8 feet) when born. The largest sizes for male and female are 4.8 meters and 4.9 meters, respectively. The size of these whales at birth are about two meters.
, California
, the Galapagos Islands
, New South Wales
, New Zealand
, Sri Lanka
, the Maldives
, and the Strait of Malacca. Its range is essentially tropical and temperate waters in the Indian and Pacific Ocean. There is no way to estimate the population.
, who occasionally take an individual. They are also affected by drift gillnets.
Toothed whales
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
even for a beaked whale
Beaked whale
Beaked whales are 21 species of toothed whales, members of the family Ziphiidae, are notable for their elongated beaks. Beaked whales are one of the world's most extreme divers. They can dive for long periods—20 to 30 minutes is common, and 85 minute dives have been recorded—and to...
, and was named for the unusual shape of its dual teeth. It is a fairly typical-looking species, but is notable for the males not having any scarring.
Physical appearance
Ginkgo-toothed beaked whales are more robust than most mesoplodonts, but otherwise look fairly typical. Halfway through the jaw, there is a sharp curve up where the ginko leaf-shaped tooth is. Unlike other species such as Blainville's beaked whaleBlainville's Beaked Whale
Blainville's beaked whale , or the dense-beaked whale, is the widest ranging mesoplodont whale and perhaps the most documented. Henri de Blainville first described the species in 1817 from a small piece of jaw—the heaviest bone he had ever come across—which resulted in the name densirostris...
and Andrews' beaked whale
Andrews' Beaked Whale
Andrews' beaked whale , sometimes known as the deep-crest beaked whale or splay-toothed whale, is one of the most poorly known members of a poorly known genus...
, the teeth do not arch over the rostrum. The beak itself is of a moderate length. The coloration is overall dark gray on males with light patches on the front half of the beak and around the head, and small white spots on the bottom of the tail, but the location may be variable. Females are a lighter gray and have countershading. Both genders reach 4.9 meters (16 feet) in length. They are around 2.4 meters long (8 feet) when born. The largest sizes for male and female are 4.8 meters and 4.9 meters, respectively. The size of these whales at birth are about two meters.
Population and distribution
This beaked whale has had less than 20 strandings off the coasts of JapanJapan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, the Galapagos Islands
Galápagos Islands
The Galápagos Islands are an archipelago of volcanic islands distributed around the equator in the Pacific Ocean, west of continental Ecuador, of which they are a part.The Galápagos Islands and its surrounding waters form an Ecuadorian province, a national park, and a...
, New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, the Maldives
Maldives
The Maldives , , officially Republic of Maldives , also referred to as the Maldive Islands, is an island nation in the Indian Ocean formed by a double chain of twenty-six atolls oriented north-south off India's Lakshadweep islands, between Minicoy Island and...
, and the Strait of Malacca. Its range is essentially tropical and temperate waters in the Indian and Pacific Ocean. There is no way to estimate the population.
Behavior
The males probably do not engage in combat, and the species probably feeds on squid and fish. No other information is known.Conservation
The only observations of this species while alive have come from hunters off the coasts of Japan and TaiwanTaiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, who occasionally take an individual. They are also affected by drift gillnets.
Specimens
- MNZ MM002618/1, collected Pakawau, Golden Bay, New Zealand, 2004.
External links
Toothed whales