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 that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...
until recently, but the
spade-toothed whale
The spade-toothed whale (''Mesoplodon traversii'') is a very little-known species, the rarest species of beaked whale. It was first named from a partial jaw found on Pitt Island, New Zealand, in 1872; reported and illustrated in 1873 by James He ...
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 ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''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 (now ...
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 bottlenos ...
. Almost 30 years after Longman's original publication, a second skull was discovered near Danane,
Somalia
Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...
(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
Maldives (, ; dv, ދިވެހިރާއްޖެ, translit=Dhivehi Raajje, ), officially the Republic of Maldives ( dv, ދިވެހިރާއްޖޭގެ ޖުމްހޫރިއްޔާ, translit=Dhivehi Raajjeyge Jumhooriyyaa, label=none, ), is an archipelag ...
in January 2000. The other remains consisted of a skull from
Kenya
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collected some time before 1968, and two juvenile males from
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
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 the North Pacific four-toothed whale, is a species of whale ...
washed up in Kagoshima,
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, 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 ...
t
beaked whales
Beaked whales (systematic name Ziphiidae) are a family of cetaceans noted as being one of the least known groups of mammals because of their deep-sea habitat and apparent low abundance. Only three or four of the 24 species are reasonably well-kn ...
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 ...
''. 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 occurs 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.
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 ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...
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 ( ar, اَلْبَحرْ ٱلْعَرَبِيُّ, Al-Bahr al-ˁArabī) is a region of the northern Indian Ocean bounded on the north by Pakistan, Iran and the Gulf of Oman, on the west by the Gulf of Aden, Guardafui Channel ...
including the
Gulf of Aden
The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) 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 Channe ...
to
Guadalupe Island
Guadalupe Island ( es, Isla Guadalupe, link=no) 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 ...
and the
Gulf of California
The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...
(the sightings off
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
(in 1992 and 1993) are probably extralimital, as they are associated with abnormally warm water during
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date L ...
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 ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
. 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 or Comoros ( Shikomori ''Komori''; ar, جزر القمر , ''Juzur al-qamar''; french: Les Comores) form an archipelago of volcanic islands situated off the southeastern coast of Africa, to the east of Mozambique and northw ...
in the summer of 2002–2003. One whale was observed from a
whale-watching
Whale watching is the practice of observing whales and dolphins (cetaceans) in their natural habitat. Whale watching is mostly a recreational activity (cf. birdwatching), but it can also serve scientific and/or educational purposes.Hoyt, E. 20 ...
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 , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic readi ...
, as well. They have also recorded off
New Caledonia
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, map_alt = Location of New Caledonia
, map_caption = Location of New Caledonia
, mapsize = 290px
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.
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 Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
. 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 h ...
, but a possible Longman's beaked whale stranded on a beach near
Vladivostok
Vladivostok ( rus, Владивосто́к, a=Владивосток.ogg, p=vɫədʲɪvɐˈstok) is the largest city and the administrative center of Primorsky Krai, Russia. The city is located around the Zolotoy Rog, Golden Horn Bay on the Sea ...
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, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line between ...
. 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
*Y ...
the
Green Island, and
Orchid Island
Orchid Island, also known by other names, is a volcanic island off the southeastern coast of Taiwan Island. The island is part of Taiwan. It is separated from the Batanes of the Philippines by the Bashi Channel of the Luzon Strait. It is gove ...
. An entangled individual was saved by local fishermen off
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
in 2015.
Since Dalebout et al. (2003), additional strandings have been reported in the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
(2004),
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
and
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
(2005), the
Andaman Islands
The Andaman Islands () are an archipelago 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 maritime boundary between th ...
(2009), and
Maui
The island of Maui (; Hawaiian: ) is the second-largest of the islands of the state of Hawaii at 727.2 square miles (1,883 km2) and is the 17th largest island in the United States. Maui is the largest of Maui County's four islands, which ...
(2010).
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 species are the long-finned pilot whale (''G. melas'') and the short-finned pilot whale (''G. macrorhynchus''). The two are not readily distinguishable at sea, a ...
s,
bottlenose dolphin
Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common ...
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 only species in the genus ''Megaptera''. Adults range in length from and weigh up to . The hump ...
s.
Tropical bottlenose whales have been known to
breach
Breach, Breached, or The Breach may refer to:
Places
* Breach, Kent, United Kingdom
* Breach, West Sussex, United Kingdom
* ''The Breach'', Great South Bay in the State of New York
People
* Breach (DJ), an Electronic/House music act
* Miroslava ...
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.
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