Stejneger's beaked whale

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Stejneger's beaked whale
Mesoplodon stejnegeri.jpg
Stejneger's beaked whale size.svg
Size compared to an average human
CITES Appendix II (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Ziphiidae
Genus: Mesoplodon
Species:
M. stejnegeri
Binomial name
Mesoplodon stejnegeri
True, 1885
Cetacea range map Stejneger sBeaked Whale.png
Stejneger's beaked whale range

Stejneger's beaked whale (Mesoplodon stejnegeri), also known as the Bering Sea beaked whale or the saber-toothed whale, is a relatively unknown member of the genus Mesoplodon inhabiting the North Pacific Ocean. Leonhard Hess Stejneger collected the type specimen (a beach-worn skull) on Bering Island in 1883, from which Frederick W. True provided the species' description in 1885. In 1904, the first complete skull (from an adult male that had stranded near Newport, Oregon) was collected, which confirmed the species' validity. [3] The most noteworthy characteristic of the males is the very large, saber-like teeth, hence the name.

Description

Stejneger's beaked whale skull located at Marine World Uminonakamichi. Mesoplodon stejnegeri by OpenCage.jpg
Stejneger's beaked whale skull located at Marine World Uminonakamichi.

The body for this species is typical for a mesoplodont, long and tapering at both ends. The beak is of medium length, and the mouthline forms an arch, though much smoother than other species. The teeth of the males are much larger than those of most other mesoplodonts and point forwards and inwards right in front of the apex. Only strap-toothed whales and spade-toothed whales have longer teeth. The coloration is overall dark gray to black on the body with light coloration below, and around the head giving it a "helmeted" appearance. The coloration darkens with age, but females have a light pattern on the bottom of the flukes that becomes more apparent with age. Like most species, scars occur on the males (from other males) and cookiecutter shark bites are present on both sexes. The length is at least 5.25 m (17 ft) for males and 5.5 m (18 ft) for females. They are likely around 2.1 to 2.3 m (6.9 to 7.5 ft) in length when born.

Population and distribution

This is the northernmost species of beaked whale in the Pacific Ocean, ranging up into the Bering Sea. They are distributed along both sides of the Pacific to Miyagi Prefecture, Japan and southern California. They may migrate south in winter.

Behavior

The whales are typically found in groups of three to four and sometimes up to 15 animals in a very close group. The groups may have age and sex segregation. Adult males fight each other extensively, and some specimens have been found with healed jaw fractures.

Conservation

This species has been occasionally hunted in Japan in the past, and occasionally been caught in drift nets. It is uncertain how much this affects the population.

See also

Related Research Articles

<span class="mw-page-title-main">Beaked whale</span> Family of mammals

Beaked whales are a family of cetaceans noted as being one of the least-known groups of mammals because of their deep-sea habitat, reclusive behavior and apparent low abundance. Only three or four of the 24 existing species are reasonably well-known. Baird's beaked whales and Cuvier's beaked whales were subject to commercial exploitation, off the coast of Japan, while the northern bottlenose whale was extensively hunted in the northern part of the North Atlantic in the late 19th and early 20th centuries.

<span class="mw-page-title-main">Andrews' beaked whale</span> Species of mammal

Andrews' beaked whale, sometimes known as the deep-crest beaked whale or splay-toothed whale, is one of the least known members of a poorly known genus. The species has never been observed in the wild, and is known only from specimens washed up on beaches.

<i>Mesoplodon</i> Genus of beaked whales

Mesoplodont whales are 16 species of toothed whale in the genus Mesoplodon, making it the largest genus in the cetacean order. Two species were described as recently as 1991 and 2002, and marine biologists predict the discovery of more species in the future. A new species was described in 2021. They are the most poorly known group of large mammals. The generic name "mesoplodon" comes from the Greek meso- (middle) - hopla (arms) - odon (teeth), and may be translated as 'armed with a tooth in the centre of the jaw'.

<span class="mw-page-title-main">Sowerby's beaked whale</span> Species of mammal

Sowerby's beaked whale, also known as the North Atlantic or North Sea beaked whale, is a species of toothed whale. It was the first mesoplodont whale to be described. James Sowerby, an English naturalist and artist, first described the species in 1804 from a skull obtained from a male that had stranded in the Moray Firth, Scotland, in 1800. He named it bidens, which derives from the two teeth present in the jaw, now known to be a very common feature among the genus.

<span class="mw-page-title-main">Hubbs' beaked whale</span> Species of mammal

Hubbs' beaked whale was initially thought to be an Andrews' beaked whale when discovered by ichthyologist Carl Hubbs; however, it was named in his honor when it was discovered to be a new species. This species has the typical dentition found in the genus, but its main outstanding features are a white "cap" on the head and very extensive scarring. The species is known from 31 strandings, a few at-sea sightings, and observations of two stranded whales that were kept in captivity for 16–25 days.

<span class="mw-page-title-main">Blainville's beaked whale</span> Species of mammal

Blainville's beaked whale, or the dense-beaked whale, is believed to be the widest ranging mesoplodont whale. The French zoologist 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. Off the northeastern Bahamas, the animals are particularly well documented, and a photo identification project started sometime after 2002.

<span class="mw-page-title-main">Gervais's beaked whale</span> Species of whale

Gervais's beaked whale, sometimes known as the Antillean beaked whale, Gulf Stream beaked whale, or European beaked whale is the most frequently stranding type of mesoplodont whale off the coast of North America. It has also stranded off South America and Africa.

<span class="mw-page-title-main">Ginkgo-toothed beaked whale</span> Species of mammal

The ginkgo-toothed beaked whale 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.

<span class="mw-page-title-main">Gray's beaked whale</span> Species of mammal

Gray's beaked whale, sometimes known as Haast's beaked whale, the scamperdown whale, or the southern beaked whale, is one of the better-known members of the genus Mesoplodon. This species is fairly gregarious and strands relatively frequently for a beaked whale. In the Māori language, this species is called hakurā or iheihe.

<span class="mw-page-title-main">Hector's beaked whale</span> Species of mammal

Hector's beaked whale, is a small mesoplodont living in the Southern Hemisphere. This whale is named after Sir James Hector, a founder of the colonial museum in Wellington, New Zealand. The species has rarely been seen in the wild.

<span class="mw-page-title-main">Strap-toothed whale</span> Species of whale

The strap-toothed beaked whale, also known as Layard's beaked whale, is one of the largest members of the mesoplodont genus, growing to 6.2 m (20 ft) in length and reaching up to 1,300 kg (2,900 lb). The common and scientific name was given in honor of Edgar Leopold Layard, the curator of the South African Museum, who prepared drawings of a skull and sent them to the British taxonomist John Edward Gray, who described the species in 1865.

<span class="mw-page-title-main">True's beaked whale</span> Species of mammal

True's beaked whale is a medium-sized whale in the genus Mesoplodon. It is native to the northern Atlantic Ocean. The common name is in reference to Frederick W. True, a curator at the United States National Museum.

<span class="mw-page-title-main">Tropical bottlenose whale</span> Species of mammal

The tropical bottlenose whale, also known as the Indo-Pacific beaked whale or Longman's beaked whale, was considered to be the world's rarest cetacean until recently, but the spade-toothed whale now holds that position. As of 2010, the species is now known from nearly a dozen strandings and over 65 sightings. This is the only species in the genus Indopacetus.

<span class="mw-page-title-main">Pygmy beaked whale</span> Species of mammal

The pygmy beaked whale, also known as the bandolero beaked whale, Peruvian beaked whale and lesser beaked whale, is the smallest of the mesoplodonts and one of the newest discoveries. There were at least two dozen sightings of an unknown beaked whale named Mesoplodon sp. A before the initial classification, and those are now believed to be synonymous with the species. The species was formally described in 1991, based on ten specimens obtained from Peru between 1976 and 1989, including a 3.72 m (12.2 ft) adult male as the type specimen. A specimen that stranded at Paracas, Peru in 1955 has since been identified as a pygmy beaked whale. Since 1987, there have been an additional 40 sightings of the species, for a total of 65.

<span class="mw-page-title-main">Cuvier's beaked whale</span> Species of whale

The Cuvier's beaked whale, goose-beaked whale, or ziphius is the most widely distributed of all beaked whales in the family Ziphiidae. It is smaller in size than most baleen whales—and indeed the larger toothed cetaceans —yet it is large among the beaked whales and smaller cetaceans, appearing somewhat like a bigger and stockier bottlenose dolphin. Cuvier's beaked whale is pelagic, generally inhabiting waters deeper than 300 m (1,000 ft), though it has been observed closer to shore on occasion. In these offshore waters, Cuvier's beaked whale executes some of the deepest, longest recorded dives among whales, and extant mammals, at 2,992 m (9,816 ft), for 222 minutes. While likely diving to forage and hunt prey, such as cephalopods, and potentially evade predators, the frequency and exact reason for these extraordinary dives is unclear. Despite its deepwater habitat, it is one of the most frequently-spotted beaked whales when surfacing.

<i>Berardius</i> Genus of mammals

The four-toothed whales or giant beaked whales are beaked whales in the genus Berardius. They include Arnoux's beaked whale in cold Southern Hemispheric waters, and Baird's beaked whale in the cold temperate waters of the North Pacific. A third species, Sato's beaked whale, was distinguished from B. bairdii in the 2010s.

<span class="mw-page-title-main">Baird's beaked whale</span> Species of mammals

Baird's beaked whale, also known as the northern giant bottlenose whale, North Pacific bottlenose whale, giant four-toothed whale, northern four-toothed whale and the North Pacific four-toothed whale, is a species of whale from the genus Berardius. Baird's and Arnoux's beaked whales are so similar that researchers have debated whether or not they are simply two populations of the same species. However, genetic evidence and their wide geographical separation has led them to be classified as separate. Baird's beaked whale is the second largest living species of toothed whale after the sperm whale.

<span class="mw-page-title-main">Perrin's beaked whale</span> Species of mammal

Perrin's beaked whale is part of the toothed whale suborder and is one of over 90 known cetaceans in existence today. Beaked whales are part of the family Ziphiidae, which are the second most diverse group out of all marine mammals with over 20 species currently recognized. Although diverse, little is understood about these timid, deep divers that can dive for up to two hours. The whales are partially named after their beak shaped jaw, which extends from their small head. The genus name Mesoplodon comes from the Greek meanings of meso- (middle), - hopla (arms), - odon (teeth), and may be translated as 'armed with a tooth in the center of the jaw'.

<span class="mw-page-title-main">Spade-toothed whale</span> Species of beaked whale

The spade-toothed whale is a very little-known species, the rarest species of beaked whale.

Deraniyagala's beaked whale is a species of mesoplodont whale closely related to the ginkgo-toothed beaked whale.

References

  1. Pitman, R.L.; Brownell Jr.; R.L. (2020). "Mesoplodon stejnegeri". IUCN Red List of Threatened Species . 2020: e.T13252A50367496. doi: 10.2305/IUCN.UK.2020-3.RLTS.T13252A50367496.en .
  2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. True, F.W. 1910. An account of the beaked whales of the family Ziphiidae in the collection of the United States National Museum, with remarks on some specimens in other American museums. Washington: Government Printing Office.

Sources