Indopacetus pacificusLongman's beaked whale

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Geographic Range

Specimens are recorded from Australia, Somalia, South Africa, the Maldives, Kenya, and Japan. From this information, the full range is currently thought to be the Eastern Pacific through the Indian Ocean to the eastern coast of Africa. Specimens have appeared rarely but widely throughout the Western Pacific and Indian Oceans. Until 2002, this species was only known by two skull specimens, recovered in 1926 and 1968. Flesh samples and live sightings have only been documented very recently. ("Indopacetus pacificus (Longman's beaked whale)", 2005; Dalebout, et al., 2003)

Habitat

Longman’s beaked whales are pelagic and feed in the deep sea. This conclusion is based on the extreme rarity of sightings and the lifestyles of related species. Also, a specimen was discovered off the coast of Japan in July of 2002. This specimen had distinctive bites from a cookie cutter shark (Isistius brasiliensis). This shark generally lives in the deep sea and its bites are common in deep sea marine life. There is very little data for any of the species in the family Ziphiidae, but one study found that the maximum depth for this related species was 1267 meters. ("Indopacetus pacificus (Longman's beaked whale)", 2005; Johnson, et al., 2004; Miller, 2005)

Physical Description

Size estimates range from 4 to 9 meters based on extrapolation from skull measurements. A Japanese specimen was 6.5 meters in length, which seems about average based on partial skeletal specimens. Like all beaked whales, this species has a prominent slender beak. Also diagnostic of beaked whales, the throat has two grooves which form a V shape and the fluke is not notched. This whale has a proportionately smaller head than most beaked whales. It is, however, larger overall than most of its close relatives. Longman’s beaked whales are most morphologically similar to Baird’s beaked whales (Beradius bairdii). They may be distinguished, however, because Longman’s beaked whales have a blow hole with concavity oriented forward, toward the anterior of the whale. In Baird’s whales the blow hole tilts toward the posterior. The dorsal fin is larger than that of most beaked whales. The lower jaw contains only a pair of oval teeth, which do not protrude from the jaw. The skin coloration varies between brown and bluish gray and tends to lighten around the flank and head. These whales are sexually dimorphic, with males tending to be larger. Weight estimates could not be found. ("Indopacetus pacificus (Longman's beaked whale)", 2005; Dalebout, et al., 2003; "Indopacetus pacificus (Longman's beaked whale)", 2005; Dalebout, et al., 2003)

  • Sexual Dimorphism
  • male larger
  • Range length
    4 to 9 m
    13.12 to 29.53 ft

Reproduction

No information is available on the mating system in this species. (Evans, 1987)

No information is available on reproduction in Longman's beaked whales. In fact, very little information is known about beaked whale (Ziphiidae) reproduction in general. Most toothed whales (Odontoceti), the mammalian suborder that includes beaked whales, have a gestation period of ten to twelve months. Lactation may last from 18 to 24 months, or more. Calving generally occurs every two or three years, and some females may become pregnant while still lactating. Males tend to be larger and reach sexual maturity later. (Evans, 1987)

  • Breeding interval
    There is no information on breeding interval.
  • Breeding season
    There is no information on breeding season in Longman's beaked whales.

Like all placental mammals (Eutheria), female beaked whales gestate young for an extended period, and protect and nourish them until they reach independence. Some whales travel in family groups and maintain bonds after young have reached independence. No specific information is available for Longman's beaked whales.

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Natural lifespan of this species is unknown; it has never been kept in captivity.

Behavior

Individuals have been sighted in the Pacific in groups of up to 100 or singly. Groups of greater than ten have been most commonly recorded. ("Indopacetus pacificus (Longman's beaked whale)", 2005)

Home Range

Home range size is unknown.

Communication and Perception

Pelagic beaked whales use echolocation to locate food. (Johnson, et al., 2004)

Food Habits

The Japanese specimen’s stomach contents were analyzed, and revealed the beaks of cephalopods. (National Science Museum, Tokyo, 2002)

  • Animal Foods
  • mollusks

Predation

Based on the distinctive bites visible on the Japanese specimen, cookie cutter sharks (Isistius brasiliensis) may feed on Longman’s beaked whales. Their large size makes them unlikely prey. (National Science Museum, Tokyo, 2002; Baird, et al., 2000)

  • Known Predators
    • Isistius brasiliensis (cookie cutter shark)

Ecosystem Roles

The stomach contents of a Japanese specimen revealed parasitic nematodes. Specifically, Anisakis individuals were extracted. These roundworms are known to parasitize cetaceans. (National Science Museum, Tokyo, 2002; Ritter, 2005)

  • Ecosystem Impact
  • creates habitat
Commensal/Parasitic Species

Economic Importance for Humans: Positive

Longman's beaked whales are important members of healthy ocean ecosystems.

Economic Importance for Humans: Negative

It is unlikely that beaked whales have negative impacts on humans.

Conservation Status

There is very little information on Longman's beaked whales, they are considered data deficient by the IUCN and are not listed by CITES or the U.S. Endangered Species Act.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Ellen Chenoweth (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

Glossary

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

echolocation

The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

pelagic

An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

2005. "Indopacetus pacificus (Longman's beaked whale)" (On-line). IBIS Seamap. Accessed October 14, 2005 at (http://seamap.env.duke.edu/species/tsn/180502).

Baird, R., P. Clapham, J. Christal, R. Connor, J. Mann, A. Read, R. Reeves, A. Samuels, P. Tyack, L. Weilgart, H. Whitehead, R. Wells, R. Wrangham. 2000. Cetacean Societies. Chicago: University of Chicago Press.

Ballance, L., R. Pitman. 1998. Cetaceans of the Western Tropical Indian Ocean:Distribution, Relative Abundance, and Comparisons with Cetacean Communities of Other Tropical Ecosystems. Marine Mammal Science, 14: 429-459. Accessed November 14, 2005 at http://apt.allenpress.com/aptonline/?request=get-abstract&issn=0824-0469&volume=014&issue=03&page=0429.

Dalebout, M., G. Ross, C. Baker, R. Anderson, P. Best, V. Cockcroft, H. Hinsz, V. Peddemors, R. Pitman. 2003. Appearance, Distribution and Genetic Distinctiveness of Longman's Beaked Whale, Indopacetus Pacificus. Marine Mammal Science, 19/3: 421-462. Accessed November 14, 2005 at http://whitelab.biology.dal.ca/md/Indopacetus_2003.pdf.

Dawson, W., R. Defran, T. Dohl, L. Herman, A. Irvine, C. Madsen, K. Norris, A. Popper, K. Pryor, M. Scott, W. Tavolga, R. Wells. 1980. Cetacean Behavior. 1980: John Wiley & Sons, Inc..

Evans, P. 1987. The Natural History of Whales & Dolphins. New York: Facts On File.

Johnson, M., P. Madsen, W. Zimmer, N. Aguilar de Soto, P. Tyack. 2004. Beaked Whales Echolocate on Prey. Proceedings of the Royal Society B: Biological Sciences, 271: S383-S386. Accessed April 18, 2006 at http://www.journals.royalsoc.ac.uk/(plauys452mdttjfuxbnps255)/app/home/content.asp?referrer=contribution&format=3&page=1&pagecount=4.

Miller, J. 2005. "Animal Diversity Web" (On-line). Accessed October 14, 2005 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Isistius_brasiliensis.html.

National Science Museum, Tokyo, 2002. "An Unidentified Beaked Whale Found Stranded in Kagoshima" (On-line). Marine Mammals Information Database. Accessed October 14, 2005 at http://svrsh1.kahaku.go.jp/sendai/indexE.html.

Ritter, J. 2005. "Anisakis simplex" (On-line). Animal Diversity Web. Accessed October 14, 2005 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Anisakis_simplex.html.