Overview

Distribution

Range Description

All five specimens so far examined have been from southern and central California (between 32° and 37°N), and it is likely that this species is endemic to the North Pacific Ocean (possibly even the eastern North Pacific) (Dalebout et al. 2002).
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Geographic Range

At present, Perrin's beaked whales (Mesoplodon perrini) are only found in the northern Pacific Ocean. Four of the five known specimens of this whale species were found stranded along the coast of southern California within 85 kilometers of one another in the late 1970's. Although this suggests an eastern distribution within the North Pacific, there is currently too little information to come to any firm conclusions. Scars attributed to cookie cutter sharks (Isistius) that were found on one of the type specimens indicates that M. perrini may migrate through tropical regions where this shark is found in surface waters. However, it could also indicate a more northern distribution of Isistius.

Biogeographic Regions: pacific ocean (Native )

  • Dalebout, M., J. Mead, C. Baker, A. Baker, A. Van Helden. 2002. A New Species of Beaked Whale Mesoplodon perrini Sp. N. (Cetacea: Ziphiidae) Discovered Through Phylogenetic Analyses of Mitochondrial DNA Sequences. Marine Mammal Science, 18/3: 577-608.
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Standing distribution

Stranding Distribution

Stranding records occur from Monterey to San Diego in California, but oval scarring typically of cookie cutter sharks indicates that species may exist in more southern waters preferred by Isistius. It may also be possible that Isistius has a more northern range than is currently reported.

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Physical Description

Morphology

Physical Description

Mesoplodon perrini is similar in shape to other members of this genus, with a short head and tail, a long abdomen, and a deep caudal peduncle. Like its closest relatives, Mesoplodon hectori and Mesoplodon peruvianus, it has a relatively short snout. It has a crescent-shaped blowhole with the tips facing towards the head. The mouth forms a straight line, and a series of grooves are present along the throat. As adults, M. perrini have dark gray coloration on their backs which grades to white on their undersides. The ventral side of their tail flukes is a lighter shade of grey with striations. Juvenile type specimens have a somewhat different color pattern, with a white area around the throat and a dark grey patch around the rostrum and eyes. Only the original five beached specimens have been accurately measured. The adult female was approximately 4.4 meters from nose to tail, while the adult male was 3.9 meters in length. The other three specimens were juvenile males, which were measured at 2.1, 2.2, and 2.4 meters.

Like other mesoplodont whales, male M. perrini have a set of tusk-like teeth that originate from the lower jaw. These tusks are not present in females. It is thought that they play a role in intrasexual competition, as is evidenced by a series of long, white scars along the flank of the adult male type specimen. The tusks may also help these whales distinguish individuals belonging to their species from those of similar, sympatric species.

Mesoplodon perrini is similar in appearance to a related species, M. hectori. In fact, many of the type specimens of this species were originally identified as the latter species, and were only designated as a separate species by Dalebout in 2002. Morphological characteristics that set these two species apart include minor differences in the cranium, teeth, and mandible.

Most of the characteristics that set M. perrini apart from related species are molecular. Substantial differences in mtDNA and cytochrome b form the basis for its diagnosis as a new species. Morphological similarities suggested that the closest relative of M. perrini was M. hectori. However, based on the molecular characters, Dalebout et al. concluded that its true sister species is M. peruvianus. This conclusion was later supported by analysis of nuclear actin sequences by Dalebout et al. (2004).

Range length: 2.10 to 4.43 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: ornamentation

  • Dalebout, M., C. Baker, J. Mead, V. Cockcroft, T. Yamada. 2004. A Comprehensive and Validated Molecular Taxonomy of Beaked Whales, Family Ziphiidae. Journal of Heredity, 95/6: 459-473.
  • MacLeod, C. 2000. Species recognition as a possible function for variations in position and shape of the sexually dimorphic tusks of Mesoplodon whales. Evolution, 54/6: 2171-2173.
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Tooth morphology

Tooth position

A single pair of teeth are positioned sub-terminally at the apex of the mandible.

Tooth exposure

Nearly all of erupted teeth in adult males are exposed above the gumline. Teeth do not erupt in females or juveniles.

Tooth shape

The shape of the exposed tooth is a rough isosceles triangle, but with a smoothly convex anterior margin. Angle formed by the denticle is 60 to 65 degrees. Dimensions for an adult male tooth measured 64 mm long, 47 mm wide, and 12 mm broad.

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Skull morphology

Diagnostic features of the skull and mandible

On the vertex of the dorsal skull the premaxillary bone extends forward of the nasal and frontal bones. Separates from Berardius and Ziphius.

A sulcus (groove) running along the middle of the combined surfaces of the nasal bones so depresses their combined middle that it is the lateral portion of each nasal bone that reaches farthest forward on the vertex. Separates from Tasmacetus and Indopacetus.

When the skull is upright and the long axis of the anterior half of the beak is horizontal, a horizontal plane transecting the summit of either maxillary prominence transects the mesethmoid bone. Separates from Hyperoodon.

Tooth alveoli of mandible are positioned at the apex of the mandible.Separates from M. bidens, M. bowdoini, M. carlhubbsi, M. densirostris, M. europaeus, M. grayi, M. ginkgodens, M. layardii, M. peruvianus, M. stejnegeri, and M. traversii.

The space between the nasals is narrow and reversed "V" shaped Separates from M. hectori and M. mirus.

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External Morphology

Head Shape

The rostrum is relatively short compared to all other species in the genus, except, M. hectori and M. peruvianus. The melon forms a small bulge. The mouthline is straight.

Coloration

Adult males are dark gray dorsally and grade to white ventrally. The ventral side of the tail flukes are pale gray with converging striations. There is a white patch around the umbilical scar. White linear scars are present on adult males, but appear to have been made by single tooth. Coloration of adult females has not been described.

Size

Adult body length range is unknown. Recorded maximum body length for adult males and females is 3.9 m and 4.4 m, respectively. Length at birth is 2.1 m.

Most Likely Confused With:

Mesoplodon peruvianus

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Type Information

Type for Mesoplodon perrini Dalebout et al., 2002
Catalog Number: USNM 504853
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Male;
Preparation: Unknown; Anatomical
Collector(s): J. Mead & G. Carsten
Year Collected: 1978
Locality: Carlsbad, 0.5 Miles South Of The Power Plant., San Diego, California, United States, Gulf Of Santa Catalina, North America, North Pacific Ocean
  • Type: Dalebout, M. L., et al. 2002. Marine Mammal Science. 18 (3): 577-608.
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Ecology

Habitat

oceanic
  • UNESCO-IOC Register of Marine Organisms
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Habitat and Ecology

Habitat and Ecology
Like other members of the genus, these species presumably prefers oceanic habitats with waters greater than 1,000 m deep, and the sightings thought to be of this species have occurred in deep waters.

Based on a limited sample of stomach contents, Perrin's beaked whale probably feeds mainly on squids (including Octopoteuthis sp.). The remains of an unidentified invertebrate have been found in the stomach of an animal stranded in California.

Systems
  • Marine
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Like most other ziphiids, Mesoplodon perrini spends the majority of its time in deep oceanic waters over 1,000 meters deep.

Habitat Regions: temperate ; saltwater or marine

Aquatic Biomes: pelagic

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Trophic Strategy

Food Habits

At present, there is limited information regarding the diet and feeding habits of Mesoplodon perrini. However, it is suspected that these whales feed primarily on squid and some fish, as do many other ziphiids. This is supported by gut content analysis of two of the type specimens. One contained the eye lens of a squid, and the other contained two squid beaks (identifed as Octopoteuthis deletron) and unidentified vertebrate parts.

Animal Foods: fish; mollusks

Primary Diet: carnivore (Piscivore , Molluscivore )

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Associations

Ecosystem Roles

Members of this species consume fish and squid. They are probably not significant as prey for other animals.

Commensal/Parasitic Species:

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Predation

The only known predators of Mesoplodon perrini are sharks and humans. Scars left by cookiecutter shark bites (Isistius) were present on one of the type specimens, but they did not appear to have caused any lasting damage. Although mesoplodont whales were never harvested commercially, there have been reports of them being taken by humans from time to time.

Known Predators:

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Life History and Behavior

Behavior

Communication and Perception

Although little is known about how Mesoplodon perrini communicates, research on other  species of mesoplodont whales indicates that they have the ability to echolocate. A 2004  study involving tagged Mesoplodon densirostris found that these animals are very vocal, most frequently emitting ultrasonic clicks that are well outside the range of human hearing. This research also revealed that these whales only emit clicks when they are below 200 meters depth, where they most commonly forage.

Communication Channels: acoustic

Perception Channels: acoustic ; echolocation

  • Johns, M., P. Madsen, W. Zimmer, N. Aguilar de Stoto, P. Tyack. 2004. Beaked whales echolocate on prey. Proceedings of the Royal Society of London, 271: S383-S386.
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Life Expectancy

Lifespan/Longevity

Since Mesoplodon perrini is such an elusive species, as is typical of this genus, nothing is known about its longevity and life history.

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Reproduction

No information is available on mating in Mesoplodon perrini.

There is currently little information available regarding reproductive habits of Mesoplodon perrini or other ziphiids. The two adult type specimens were both sexually mature, and an analysis of the teeth indicated an approximate age of 9 years for both of them.

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Little is known about parental investment in Mesoplodon perrini. However, the 2.1 meter type specimen had a fringed tongue, which indicates that it was not yet weaned when it died. Researchers suspect that it was the calf of the adult female type specimen, and that it was still dependent on her when she was stranded. Like all other whales, young are able to swim soon after birth.

Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female); pre-independence (Provisioning: Female, Protecting: Female)

  • Dalebout, M., J. Mead, C. Baker, A. Baker, A. Van Helden. 2002. A New Species of Beaked Whale Mesoplodon perrini Sp. N. (Cetacea: Ziphiidae) Discovered Through Phylogenetic Analyses of Mitochondrial DNA Sequences. Marine Mammal Science, 18/3: 577-608.
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
DD
Data Deficient

Red List Criteria

Version
3.1

Year Assessed
2008

Assessor/s
Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.

Reviewer/s
Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)

Contributor/s

Justification
There is no information on global abundance or trends in abundance for this species. It is likely uncommon and potentially vulnerable to low-level threats and a 30% global reduction over three generations cannot be ruled out (criterion A).

History
  • 2003
    Not Evaluated
    (IUCN 2003)
  • 2003
    Not Evaluated
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Since so little is known about the habits of Mesoplodon perrini, and so few individuals have been encountered in the wild, it is difficult to adequately evaluate how many individuals are left and what potential threats (if any) there are to the survival of the species. According to the ICUN, this species has the potential to become caught in certain types of fishing gear, such as deepwater gill nets used for capturing large pelagic fish species. Like other marine mammals, it may also be negatively impacted by navy sonar and loud noises generated by seismic exploration. Climate change may also cause their range to change or grow smaller, but since the specific range of M. perrini has yet to be determine, this assertion is presently based only on conjecture.

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: data deficient

  • International Union for the Conservation of Nature and Natural Resources. 2008. "IUCN 2008 Red List - Mesoplodon perrini" (On-line). The IUCN Red List of Threatened Species. Accessed April 07, 2009 at http://www.iucnredlist.org/details/41759.
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Population

Population
No estimates of abundance exist, but the species does not appear to be common. There are only two possible sightings of live individuals.

Population Trend
Unknown
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Threats

Major Threats
All confirmed records have been of strandings (plus two possible sightings), so nothing is known of potential threats. Beaked whales of this genus have been taken occasionally by whalers but are not presently the main targets of any hunt. Entanglement in fishing gear, especially gillnets in deep water (e.g., for billfish and tuna), is probably the most significant threat.

This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).

As a species with an apparently restricted distribution, Perrin’s beaked whale may be vulnerable to the effects of climate change as ocean warming may result in a shift or contraction of the species range as it tracks the occurrence of its preferred water temperatures (Learmonth et al. 2006). The effect of such changes in range size or position on this species is unknown.

Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.
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Management

Conservation Actions

Conservation Actions
The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.
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Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

Members of this species are probably too rare to have a significant negative impact on humans.

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Economic Importance for Humans: Positive

Members of this species are probably to rare to be important to humans.

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Risks

IUCN Red List Category

Data Deficient (DD)
  • IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
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Wikipedia

Perrin's beaked whale

Perrin's beaked whale!<-- This template has to be "warmed up" before it can be used, for some reason -->

Perrin's beaked whale (Mesoplodon perrini) is the newest species of beaked whale to be described. It was first found in May 1975 off the coast of California, with four more specimens appearing in September 1997. They were initially identified as Hector's beaked whale (Mesoplodon hectori), except for the most recent one which was assumed to be a neonate Cuvier's beaked whale[2]. Following inclusion of one of these specimens in a mtDNA sequence database of beaked whales, it turned out that they seemed well distinct from M. hectori (Dalebout et al. 1998). It was subsequently confirmed that the other "Hector's" specimens from California belonged to the same undescribed taxon (Dalebout 2002). The new species was formally described in 2002 by Dalebout et al.; its common and specific names are a tribute to cetologist William F. Perrin.

Despite the superficial similarities to the (entirely allopatric) Hector's Beaked Whale, this species is closely related to the pygmy beaked whale, the next most recently described species, and probably represents its Northern Hemisphere sister species.

Perrin's Beaked Whale has not definitely been recorded alive by scientists. However, its appearance is known from the beached specimens, and following resolution of their identity as a new species, it seems highly likely that 3 supposed "Hector's Beaked Whales" which were seen off California in 1976 (2 individuals) and 1978 (one individual) were actually this species (Mead 1981, Dalebout et al. 2002).

Contents

Description

Perrin's Beaked Whale cannot be identified with absolute certainty at sea. However, the combination of small size, appearance and presumed range makes a confusion unlikely. Stranded specimens can be identified as this species by either DNA sequence data and/or anatomical details of the skull.(Dalebout et al. 2002)

This species has a fairly typical body shape for a mesoplodont with a small head, long body, and deep tail. The rostrum of this whale is shorter than every other mesoplodont other than Hector's Beaked Whale and the Pygmy Beaked Whale, especially in young individuals. The mouthline of this species is straight, and the melon forms a small bulge with a crescent-shaped blowhole with forward-pointing tips. The teeth on this species are fairly large and towards the tip of the mouth. Throat grooves are present on this species. The mature male specimen was 3.9 meters in length (13 feet) and the female was 4.4 meters (14 feet 8 inches) in length; the immature males measured between 2.1 and 2.45 meters (7-7.5 ft).

The coloration is dark gray above and white below in the holotype male, with a lighter gray underside of the tail fluke. A white patch is present near the navel. The coloration of females is not known, since the only specimen was rather decomposed. Calves are light to dark gray on top, and white below, including the lower jaw and throat; the uinderside of the flukes is lighter gray. There is a dark "mask" on the head, from the corners of the mouth to the eye region, the rostrum, and the melon, and there are white stripes on the tail underside. The adult male had the typical white scar-stripes from fights with conspecifics. Only adult males seem to have teeth, and even these only two, in line with other Mesoplodon species. In Perrin's beaked whale, the teeth are located near the tip of the lower jaw and are roughly equilateral triangles when viewed laterally and still placed in the jaw; in this they resemble the foreteeth of Baird's beaked whale more than those of the Mesoplodon species which are otherwise similar.(Dalebout et al. 2002)

A photograph of a possible living specimen - one of the 2 observed in 1976 - is featured in Rice (1978: 95) as "Mesoplodon carlhubbsi", a distinctly larger species also native to the waters off California. Recordings of the animals' vocalizations were also made on this opportunity.(Mead 1981)

Distribution and status

This species has only been found off the coast of California between San Diego and Monterey. It likely lives offshore the Pacific coast of North America - and possibly elsewhere in the northern Pacific - in waters 1,000 meters deep or more. However, evidence is lacking and the northern and southern limits of its range are entirely unknown (though biogeography of beaked whales suggests it does not reach the Equator). No population estimate or assessment of conservation status has hitherto been possible. San Clemente Island holds a sonar research facility of the US Navy; such research has in the past been implicated in causing strandings of cetaceans (see Beached whale).

Ecology and behavior

Nothing is known of this species' behavior in life. However, as this is apparently quite similar in all Mesoplodon, a number of well-founded assumptions can be made.

The males of this species seem to engage in fights like most other mesoplodonts. Scars from fighting are present on this species, although the precise mechanism of combat is enigmatic: given the teeths' position near the lower jaw tips, it can be expected that the scars consist of two parallel lines; only single scar lines were present on the adult male however suggesting glancing blows rather than direct attacks created them.

Few stomach contents were available for analysis. Presumably, this species eats pelagic squid (such as Octopoteuthis deletron, remains of which were found in the female's stomach) and possibly small fish[3] like other beaked whales.

The largest immature LAM 088901, at 2.45 meters of length, was apparently independent from its mother. On the other hand, the smallest known specimen USNM 504259 had a fringed tongue which indicates that it was still suckling. Teeth were not present in the immatures[verification needed], but they are not needed for feeding. The dates when the specimens were found suggest that the young start to feed independently in summer; considering that most whales suckle until around one year of age suggests that the young are born during the summer half of the year. Consequently, as they are all of somewhat similar size, the immatures were probably around one year old. The adults were both an estimated 9 years old when they died.

The causes of death of 2 animals can be tentatively inferred: The 1997 specimen was starving at the time of death, possibly following a parasite infection (Dalebout et al. 2002). The 1975 female had died around May 14 (Mead 1981); given that the juvenile found on May 22 was apparently its calf and that it was not yet fully weaned, its death seems to be a direct consequence of the loss of its' mother.

As with their relatives, cookiecutter sharks attack this whale to try and bite off chunks of flesh. Such attacks are generally not life-threatening to the whale. It is a host of the thoracican barnacle Conchoderma auritum, and for one or several species of parasitic Phyllobothrium cestodes (possibly Phyllobothrium delphini) this species is either a primary or a dead-end host.

Specimens

  1. USNM 504259 - May 22, 1975; 33°15'N, 117°26'W - the smallest specimen, an immature male
  2. USNM504260 - May 28, 1975; 33°16'N, 117°26'W - an adult, the only female known to date and probably the mother of USNM 504259 (Dalebout et al. 2002)
  3. USNM504853 - September 9, 1978; 33°07'N, 117°20'W - an adult male, the holotype
  4. LAM 088901 JRH 052 - December 27, 1979; 32°55'N, 117°15'W - an immature male
  5. TMMC-C75 - September 18, 1997; 36°37'N, 121°55'W - an immature male

The 1976 possible sightings took place on July 30, the 1978 one on September 9 - the same day the holotype specimen was discovered (Mead 1981). Altogether, there is a marked concentration of sightings between May and September. It is unknown if this has any significance. Nonetheless, with the scant data at hand it still appears that looking for small beaked whales during the summer months in the area between Santa Catalina and San Clemente Islands and the mainland has the best odds of encountering this enigmatic species.

References

  • Baker, Alan N. (1990): Whales and dolphins of New Zealand and Australia: An identification guide. Victoria University Press, Wellington.
  • Carwadine, M. (1995): Whales, dolphins and porpoises. HarperCollins, London.
  • Dalebout, Merel L. (2002): Species identity, genetic diversity and molecular systematic relationships among the Ziphiidae (Beaked Whales). Ph.D. thesis, School of Biological Sciences, University of Auckland, Auckland, New Zealand. HTML abstract
  • Dalebout, Merel L.; van Helden, Anton L.; van Waerebeek, K. & Baker, C. Scott (1998): Molecular genetic identification of southern hemisphere beaked whales (Cetacea: Ziphiidae). Molecular Ecology 7(6): 687-694. doi:10.1046/j.1365-294x.1998.00380.x PDF fulltext
  • Dalebout, Merel L.; Mead, James G.; Baker, C. Scott; Baker, Alan N. & van Helden, Anton L. (2002): A New Species of Beaked Whale, Mesoplodon perrini sp. n. (Cetacea: Ziphiidae), Discovered Through Phylogenic Analysis of Mitochondrial DNA Sequences. Marine Mammal Science 18(3): 577-608. doi:10.1111/j.1748-7692.2002.tb01061.x PDF fulltext
  • Henshaw, M.D.; Leduc, R.G.; Chivers, S.J. & Dizon, A.E. (1997): Identification of beaked whales (family Ziphiidae) using mtDNA sequences. Marine Mammal Science 13(3): 487-495. doi:10.1111/j.1748-7692.1997.tb00656.x (HTML abstract)
  • Jefferson, T.A.; Leatherwood, S. & Webber, M.A. (1993): FAO species identification guide: Marine mammals of the world. United States Environment Programme & Food and Agriculture Organization of the United Nations (FAO), Rome. PDF fulltexr
  • Mead, James G. (1981): First records of Mesoplodon hectori (Ziphiidae) from the northern hemisphere and a description of the adult male. Journal of Mammalogy 62(2): 430-432. doi:10.2307/1380733 (First page image)
  • Mead, James G. (1984): Survey of reproductive data for the beaked whales (Ziphiidae). Report of the International Whaling Commission Special Issue 6: 91-96.
  • Mead, James G. (1989): Beaked whales of the genus Mesoplodon. In: Ridgway, S.H. & Harrison, R. (eds.): Handbook of marine mammals Vol.4: 349-430. Academic Press, London.
  • Mead, James G. (1993): The systematic importance of stomach anatomy in beaked whales. IBI Reports 4: 75-86.
  • Mead, James G. & Baker, Alan N. (1987): Notes on the rare beaked whale, Mesoplodon hectori (Gray). Journal of the Royal Society of New Zealand 17: 303-312.
  • Messenger, S.L. & McQuire, J.A. (1998): Morphology, molecules and the phylogenetics of cetaceans. Systematic Biology 47(1): 90-124. doi:10.1080/106351598261058 (HTML abstract)
  • Reeves, Randall R. & Leatherwood, S. (1994): Dolphins, porpoises and whales: 1994-98 Action plan for the conservation of cetaceans. IUCN, Gland, Switzerland. ISBN 2-8317-0189-9
  • Rice, D.W. (1978): Beaked whales. In: Haley, D. (ed.): Marine mammals of the eastern North Pacific and Arctic waters: 88-95. Pacific Search Press, Seattle.

Footnotes

  1. ^ Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. (2008). Mesoplodon perrini. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 24 March 2009. Database entry includes a brief justification of why this species is of data deficient.
  2. ^ These specimen provided data which erroneously has been published as referring to M. hectori, before their true identity became known - especially since the adult male of Hector's Beaked Whale has only recently been described. Dalebout et al. (2002) specifically list Mead (1981), Mead (1984), Mead & Baker (1987), Mead (1989), Baker (1990), Jefferson et al. (1993), Mead (1993), Carwardine (1995), Reeves & Leatherwood (1994), Henshaw et al. (1997) and Messenger & McQuire (1998)
  3. ^ Note that the supposed unidentifiable "vertebrate" piece discovered in the female specimen's stomach is probably a misprint; the original description of the specimen (Mead 1981) has "invertebrate".
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