Longman's Beaked Whale
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The tropical bottlenose whale (''Indopacetus pacificus''), also known as the Indo-Pacific beaked whale or Longman's beaked whale, was considered to be the world's rarest
cetacean Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...
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 Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Indopacetus''.


History of discovery

The species has had a long history riddled with misidentifications, which are now mostly resolved. A skull and jaw found on a beach in
Mackay, Queensland } Mackay () is a city in the Mackay Region on the eastern or Coral Sea coast of Queensland, Australia. It is located about north of Brisbane, on the Pioneer River. Mackay is described as being in either Central Queensland or North Queensland ...
, in 1882, provided the basis for the initial description of this species by H. A. Longman in 1926. Other researchers were not convinced, and felt this specimen might instead represent a Pacific form of
True's beaked whale True's beaked whale (''Mesoplodon mirus'') 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 (n ...
or a female
bottlenose whale ''Hyperoodon'' (or ''Hyperoödon'') is a genus of beaked whale, containing just two species: the Northern and Southern bottlenose whales. While not in the genus ''Hyperoodon'', Longman's beaked whales are alternatively called tropical bottle ...
. Almost 30 years after Longman's original publication, a second skull was discovered near Danane,
Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...
(1955). This specimen likely stranded on the coast, but was subsequently processed into fertilizer. Only the skull survived. Biologist Joseph C. Moore used this skull, together with the original Mackay specimen, to effectively demonstrate that Longman's beaked whale was a unique species and elevated it to its own genus, ''Indopacetus''. Dalebout et al. (2003) used a combination of genetic and morphological analyses to identify four further specimens, including a complete adult female with a fetus found in the
Maldives The Maldives, officially the Republic of Maldives, and historically known as the Maldive Islands, is an Archipelagic state, archipelagic country in South Asia located in the Indian Ocean. The Maldives is southwest of Sri Lanka and India, abou ...
in January 2000. The other remains consisted of a skull from
Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...
collected some time before 1968, and two juvenile males from
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
from strandings in 1976 and 1992. Based on morphological analyses, Dalebout et al. concluded that the genus ''Indopacetus'' was a valid one. The external appearance and colour pattern of this species was also revealed, and a firm connection was established with the mysterious tropical bottlenose whales that had been sighted in the Indian and Pacific Oceans since the 1960s. While this paper was in press, a specimen that was first misidentified as a
Baird's beaked whale Baird's beaked whale (''Berardius bairdii''), also known as the northern giant bottlenose whale, North Pacific bottlenose whale, giant four-toothed whale, northern four-toothed whale and North Pacific four-toothed whale, is a species of whale fro ...
washed up in Kagoshima,
Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...
, in July 2002.


Description

Longman's beaked whales look rather similar to both
mesoplodon 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 (pygmy beaked whale) and 2002 (Perrin's beaked whale), and marine b ...
t beaked whales and bottlenose whales, which led to a great deal of taxonomic confusion. The Maldives female had a robust body like the bottlenoses, although this may be a distortion, since the less-decomposed female specimen from Japan had a laterally compressed body typical of ''
Mesoplodon 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 (pygmy beaked whale) and 2002 (Perrin's beaked whale), and marine b ...
''. The juvenile specimens have a very short beak similar to a bottlenose whale, but the adult females seen so far have had rather long beaks sloping gently into a barely noticeable melon organ. Additionally, the dorsal fins of adult specimens seem unusually large and triangular for beaked whales, whereas in juveniles they are rather small and swept back. An adult male specimen has yet to wash up, but sightings of the tropical bottlenose whale indicate they have a rather bulbous melon, two teeth located towards the front of the beak, and scars from fighting with the teeth. Scars from
cookiecutter shark The cookiecutter shark (''Isistius brasiliensis''), also called the cigar shark, is a species of small squaliform shark in the family Dalatiidae. This shark lives in warm, oceanic waters worldwide, particularly near islands, and has been reco ...
s are also rather common on the whale. The rather unusual coloration of the juveniles helped connect the Longman's to the tropical bottlenose whale; both have dark backs behind the blowholes, which quickly shade down to a light gray and then white. The blackness from the back extends down to the eye of the whale except for a light spot behind the eye, and then continues on in a line towards the flipper, which is also dark. Dark markings are also present on the tip of the beak and rostrum. The females have a simpler coloration; the body is typically grayish except for a brown head. The coloration appears to be rather variable in this species. The female specimen from the Maldives was 6 m (20 ft) in length, with a 1 m (3 ft) fetus, and the Japanese female was 6.5 m (22 ft) in length. Reports of tropical beaked whales put them even longer, in the 7 to 9m (23 to 29.5 ft) range, which is larger than any mesoplodont and more typical of a bottlenose whale. No weight estimation or reproductive information is known.


Behavior

Tropical bottlenose whale observations indicate they travel in larger groups than any other local species of beaked whales. The size of the pods ranges from the tens up to 100, with 15 to 20 being typical, and the groups appear very cohesive. Their pods are sometimes associated with other species, such as short-finned
pilot whale Pilot whales are cetaceans belonging to the genus ''Globicephala''. The two Extant taxon, extant species are the long-finned pilot whale (''G. melas'') and the short-finned pilot whale (''G. macrorhynchus''). The two are not readily distinguish ...
s,
bottlenose dolphin The bottlenose dolphin is a toothed whale in the genus ''Tursiops''. They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus contains three species: the common bot ...
s,
spinner dolphin The spinner dolphin (''Stenella longirostris'') is a small dolphin found in off-shore tropical waters around the world. It is famous for its acrobatic displays in which it rotates around its longitudinal axis as it leaps through the air. It is a ...
s, and
humpback whale The humpback whale (''Megaptera novaeangliae'') is a species of baleen whale. It is a rorqual (a member of the family Balaenopteridae) and is the monotypic taxon, only species in the genus ''Megaptera''. Adults range in length from and weigh u ...
s. Tropical bottlenose whales have been known to breach the surface, and they normally have visible, but short, blows. Their dives last between 11 and 33 minutes, with one individual diving for least 45 minutes.


Population and distribution

Strandings and sightings indicate the species ranges across the
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...
from southern and eastern Africa to the Maldives, Sri Lanka, and east to Myanmar, with a Pacific range extending from Australia to Japan. However, if the sightings of tropical beaked whales are taken into account, the range of this whale is more extensive; they have been sighted from the
Arabian Sea The Arabian Sea () is a region of sea in the northern Indian Ocean, bounded on the west by the Arabian Peninsula, Gulf of Aden and Guardafui Channel, on the northwest by Gulf of Oman and Iran, on the north by Pakistan, on the east by India, and ...
including the
Gulf of Aden The Gulf of Aden (; ) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channel, the Socotra Archipelago, Puntland in Somalia and Somaliland to the south. ...
to
Guadalupe Island Guadalupe Island () is a volcanic island located off the western coast of Mexico's Baja California peninsula and about southwest of the city of Ensenada in the state of Baja California, in the Pacific Ocean. The various volcanoes are extinc ...
and the
Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...
(the sightings off
Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
(in 1992 and 1993) are probably extralimital, as they are associated with abnormally warm water during
El Niño EL, El or el may refer to: Arts and entertainment Fictional entities * El, a character from the manga series ''Shugo Chara!'' by Peach-Pit * Eleven (''Stranger Things'') (El), a fictional character in the TV series ''Stranger Things'' * El, fami ...
events). Sightings in the Gulf of Mexico are possible, which may indicate they are present in the tropical Atlantic Ocean, as well. The most frequent observations have occurred off the coasts of
Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...
. Although only a single specimen has washed up in Hawaii, they are apparently rather common; a 2002 survey estimated 766 animals. No other population estimates exist for other locales, although a single individual was apparently identified in the
Comoro Islands The Comoro Islands are a group of volcanic islands in the Mozambique Channel, an arm of the Indian Ocean lying between Madagascar and the African mainland. Three of the islands form the Union of the Comoros, a sovereign nation, while Mayotte bel ...
in the summer of 2002–2003. One whale was observed from a whale-watching vessel off Choshi in December, 2015. Possible sightings were made off
Tokara Islands The is an archipelago in the Nansei Islands, and are part of the Satsunan Islands, which is in turn part of the Ryukyu Archipelago. The chain consists of twelve small islands located between Yakushima and Amami-Oshima. The islands have a total ...
and
Bonin Islands The Bonin Islands, also known as the , is a list of islands of Japan, Japanese archipelago of over 30 subtropical and Island#Tropical islands, tropical islands located around SSE of Tokyo and northwest of Guam. The group as a whole has a total ...
, as well. They have also recorded off
New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...
. The range of Longman's beaked whales was once considered to be restricted to warmer waters of Pacific, but stranding records in recent years revealed they may migrate further north to sub-Arctic regions such as off
Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...
. No occurrence has been confirmed in the
Sea of Japan The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it ...
, but a possible Longman's beaked whale stranded on a beach near
Vladivostok Vladivostok ( ; , ) is the largest city and the administrative center of Primorsky Krai and the capital of the Far Eastern Federal District of Russia. It is located around the Zolotoy Rog, Golden Horn Bay on the Sea of Japan, covering an area o ...
in 2011. In 2009, the first confirmed sighting was made of tropical bottlenose whales in the southern
Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean. Geographically it is positioned between the Indian subcontinent and the Mainland Southeast Asia, Indochinese peninsula, located below the Bengal region. Many South Asian and Southe ...
. In the summer and fall of 2010, researchers aboard the NOAA ship ''McArthur II'' made two sightings of groups of tropical bottlenose whales off Hawaii. The first sighting consisted of a "large, active group" of over 70 individuals surfacing rapidly and breaching on occasion; the second sighting, late in October, did not last as long, as the group "ran away". Increasingly more sightings and strandings have been recorded in Taiwan and surrounding small islands such as at
Yilan Yilan may refer to: China * Yilan County, Heilongjiang (依兰县), county of central Heilongjiang province, People's Republic of China * Yilan Town, Heilongjiang (依兰镇), seat of Yilan County * Yilan, Jilin (依兰镇), town in Yanji Taiwan ...
the Green Island, and
Orchid Island Orchid Island, known as Pongso no Tao by the indigenous inhabitants, is a volcanic island located off the southeastern coast of Taiwan, the island and the nearby are governed by Taiwan as in Taitung County, which is one of the county's two ...
. An entangled individual was saved by local fishermen off
Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...
in 2015. Since Dalebout et al. (2003), additional strandings have been reported in the
Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...
(2004),
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
and
Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...
(2005), the
Andaman Islands The Andaman Islands () are an archipelago, made up of 200 islands, in the northeastern Indian Ocean about southwest off the coasts of Myanmar's Ayeyarwady Region. Together with the Nicobar Islands to their south, the Andamans serve as a mari ...
(2009), and
Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...
(2010).


Conservation

No records report the whale being hunted, although individuals have been trapped in fishing nets off Sri Lanka and a stranding in Taiwan in 2005 involving a cow-calf pair may have been due to nearby naval exercises. The tropical bottlenose whale is covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region ( Pacific Cetaceans MOU).


See also

*
List of cetaceans Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 mya (unit), million years ...


References


Further reading

*Longman's Beaked Whale Hawaiian Stock. Revised 3/15/05. Available
here
*Appearance, Distribution, and Genetic Distinctiveness of Longman's Beaked Whale, Indopacetus pacificus. Dalebout, Ross, Baker, Anderson, Best, Cockcroft, Hinsz, Peddemors, and Pitman. July 2003, Marine Mammal Science, 19(3):421–461. Available
here
*''National Audubon Society Guide to Marine Mammals of the World'' Reeves et al., 2002. . *''Sightings and possible identification of a bottlenose whale in the tropical Indo-Pacific: Indopacetus pacificus?'' Pitman, Palacios, Brennan, Brennan, Balcomb and Miyashita, 1999. ''Marine Mammal Science'' Vol 15, pp 531–549. *''Encyclopedia of Marine Mammals'' Robert L. Pitman, 1998. *''Whales, Dolphins and Porpoises'' Carwardine, 1995. *''More skull characters of the beaked whale Indopacetus pacificus and comparative measurements of austral relatives'' J.C. Moore 1972. Field Zoology. Vol 62 pp 1–19. *''Relationships among the living genera of beaked whales with classifications, diagnoses and keys'' J.C. Moore 1968. Field Zoology. Vol 53, pp 206–298.


External links


Rare whale washes up in South AfricaWhale & Dolphin Conservation Society (WDCS)
{{Taxonbar, from=Q910093 Cetaceans of the Pacific Ocean Ziphiids Mammals described in 1926