Longman's Beaked Whale
Encyclopedia
The tropical bottlenose whale (Indopacetus pacificus), also known as the Indo-Pacific beaked whale and the Longman's beaked whale, was considered to be the world's rarest cetacean until recently, but the spade-toothed whale now holds that position. 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
, Australia
in 1882 provided the initial description by H. A. Longman in 1926, but some authorities insisted on classifying it as a True's beaked whale
or a female bottlenose whale
instead of a new species. A whale washed up near Danae, Somalia
in 1955 was processed into fertilizer with only the skull remaining, and biologist Joseph C. Moore used it to effectively demonstrate it was a unique species. However, there was a considerable debate as to whether the whale belonged in the genus Mesoplodon or not. The next major development happened when a paper had shown there were actually six remains of the whale, including a complete female with a fetus found in the Maldives
in 2000. The other remains consisted of a skull from Kenya
from before 1968, and two juveniles from South Africa
in 1976 and 1992, respectively. The paper used DNA analysis to show the tropical bottlenose whale is likely to be an independent genus, but information on other species was too lacking to establish any concrete phylogeny. The external physical appearance was also revealed, and a firm connection was established with the mysterious tropical bottlenose whales sighted in the Indian and Pacific Oceans. During the publication of the paper, a specimen originally identified as a giant beaked whale
washed up in Kagoshima, Japan
in July 2002. Another specimen claimed to be a tropical bottlenose whale, which washed up in South Africa in August 2002, is likely a misidentified Cuvier's beaked whale
.
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 six metres (20 feet) in length, with a one-metre (3 foot) fetus, and the Japanese female was 6.5 metres (22 feet) in length. Reports of tropical beaked whales put them even longer, in the 7-8 metre (23–26 foot) range, which is larger than any mesoplodont and more typical of a bottlenose whale. No weight estimation or reproductive information is known.
from southern and western Africa to the Maldives, 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
to the western shore of Mexico
. They have also been seen in the Gulf of Mexico, which would indicate they are present in the tropical Atlantic Ocean as well. The most frequent observations have occurred off the coasts of Hawaii
. While no specimens have washed up on Hawaii, they are apparently rather common; a 2002 survey estimated 766 animals. No other population estimates exist for other locales.
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".
s and bottlenose dolphin
s. Tropical bottlenose whales have been known to breach the surface, and they normally have visible, but short, blows. Their dives have been clocked at 18 to 25 minutes.
Mackay, Queensland
Mackay is a city on the eastern coast of Queensland, Australia, about north of Brisbane, on the Pioneer River. Mackay is nicknamed the sugar capital of Australia because its region produces more than a third of Australia's cane sugar....
, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
in 1882 provided the initial description by H. A. Longman in 1926, but some authorities insisted on classifying it as a True's beaked whale
True's Beaked Whale
The True's Beaked Whale is a medium sized whale in the Mesoplodont genus. The common name is in reference to Frederick W. True, a curator at the United States National Museum...
or a female bottlenose whale
Bottlenose whale
The Northern bottlenose whale is a species of the ziphiid family, one of two members of the Hyperoodon genus. The northern bottlenose was hunted heavily by Norway and Britain in the 19th and early 20th centuries...
instead of a new species. A whale washed up near Danae, Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
in 1955 was processed into fertilizer with only the skull remaining, and biologist Joseph C. Moore used it to effectively demonstrate it was a unique species. However, there was a considerable debate as to whether the whale belonged in the genus Mesoplodon or not. The next major development happened when a paper had shown there were actually six remains of the whale, including a complete female with a fetus found in 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...
in 2000. The other remains consisted of a skull from Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
from before 1968, and two juveniles from South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
in 1976 and 1992, respectively. The paper used DNA analysis to show the tropical bottlenose whale is likely to be an independent genus, but information on other species was too lacking to establish any concrete phylogeny. The external physical appearance was also revealed, and a firm connection was established with the mysterious tropical bottlenose whales sighted in the Indian and Pacific Oceans. During the publication of the paper, a specimen originally identified as a giant beaked whale
Giant beaked whale
The genus Berardius contains two species of beaked whale, Baird's beaked whale and Arnoux's beaked whale. The two species are so similar, some scientists regard their separation into distinct species as a historical anomaly...
washed up in Kagoshima, Japan
Japan
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...
in July 2002. Another specimen claimed to be a tropical bottlenose whale, which washed up in South Africa in August 2002, is likely a misidentified Cuvier's beaked whale
Cuvier's Beaked Whale
Cuvier's beaked whale is the most widely distributed of all the beaked whales. It is the only member of the genus Ziphius. Another common name for the species is goose-beaked whale because its head is said to be shaped like the beak of a goose. Georges Cuvier first described it in 1823 from part...
.
Physical description
The Longman's beaked whales look rather similar to both mesoplodont 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. 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 sharkCookiecutter shark
The cookiecutter shark , also called the cigar shark, is a species of small dogfish shark in the family Dalatiidae. This shark occurs in warm, oceanic waters worldwide, particularly near islands, and has been recorded from as deep as . It migrates vertically up to every day, approaching the...
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 six metres (20 feet) in length, with a one-metre (3 foot) fetus, and the Japanese female was 6.5 metres (22 feet) in length. Reports of tropical beaked whales put them even longer, in the 7-8 metre (23–26 foot) 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
Carcasses indicate the species ranges across the Indian OceanIndian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
from southern and western Africa to the Maldives, 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
Arabian Sea
The Arabian Sea is a region of the Indian Ocean bounded on the east by India, on the north by Pakistan and Iran, on the west by the Arabian Peninsula, on the south, approximately, by a line between Cape Guardafui in northeastern Somalia and Kanyakumari in India...
to the western shore of Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. They have also been seen in the Gulf of Mexico, which would indicate they are present in the tropical Atlantic Ocean as well. The most frequent observations have occurred off the coasts of Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
. While no specimens have washed up on Hawaii, they are apparently rather common; a 2002 survey estimated 766 animals. No other population estimates exist for other locales.
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".
Behavior
Tropical bottlenose whale observations indicate they travel in larger groups than any other local species of beaked whales. The size of the pods range from the tens up to 100, with 15 to 20 being fairly typical, and the groups appear very cohesive. Their pods are frequently associated with other species, such as short-finned pilot whalePilot whale
Pilot whales are cetaceans belonging to the genus Globicephala. There are two extant species, the long-finned pilot whale and the short-finned pilot whale . The two are not readily distinguished at sea and analysis of the skulls is the best way to tell the difference between them...
s and bottlenose dolphin
Bottlenose Dolphin
Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...
s. Tropical bottlenose whales have been known to breach the surface, and they normally have visible, but short, blows. Their dives have been clocked at 18 to 25 minutes.
Conservation
There are no records of the whale being hunted, caught in fishing gear, or affected by navy sonar. Due to their rather uncommon nature, their conservation status is unknown.Sources
- 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. ISBN 0-375-41141-0.
- Sightings and possible identification of a bottlenose whale in the tropical Indo-Pacific: Indopacetus pacificus? Pitman, Palacios, Brennan, Brennan, Balcomb and Miyashita, 1999. Marine Mammology Science Vol 15, pps 531-549.
- Encyclopedia of Marine Mammals Robert L. Pitman, 1998. ISBN 0-12-551340-2
- Whales, Dolphins and Porpoises Carwardine, 1995. ISBN 0-7513-2781-6
- More skull characters of the beaked whale Indopacetus pacificus and comparative measurements of austral relatives J.C. Moore 1972. Field Zoology. Vol 62 pps 1-19.
- Relationships among the living genera of beaked whales with classifications, diagnoses and keys J.C. Moore 1968. Field Zoology. Vol 53, pps 206-298.