Articles on this page are available in 2 other languages: Spanish (29), Chinese (Simplified) (4) (learn more)

Overview

Brief Summary

Description

"This dark gray species is actually in the black dolphin family. It is smaller than almost all the other North American members of this family and is approximately the size of a bottlenose dolphin. This whale lives in deep tropical and subtropical waters around the world and is relatively rare; the total population in the world is believed to be perhaps 2,000.  They frequently school together in large herds (200) and with other small whales and dolphins. Their diet includes fish, squid, and sometimes crustaceans, similar to that of Fraser's dolphins with whom they often associate. They are very aggressive and do not survive well in captivity."

Links:
Mammal Species of the World
  • Original description: Gray, J.E., 1846.  On the cetaceous animals. Pp. 13-53, in The zoology of the voyage of H.M.S. Erebus and Terror, under the command of Captain Sir James Clark Ross, R.N., F.R.S., during the years 1839 to 1843 by the authority of the Lords Commisioners of the Admiralty (J. Richardson and J.E. Gray, eds.) p. 35.  E.W. Janson, London.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution

Source: Smithsonian's North American Mammals

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Distribution

Peponocephala electra is found in warm, deep, tropical, and subtropical oceanic waters between 40⁰ North and 30⁰ South, with most animals concentrated between 20⁰ North and 20⁰ South. While Peponocephala electra is most commonly found in the Philippine Sea, its range includes the Gulf of Mexico, Senegal, the Arabian Sea, the Bay of Bengal, the South China Sea, Taiwan, southern Honshu, the Hawaiian Islands, and Baja California Sur; and south to Espiritu Santo in Brazil, Timor Sea, northern New South Wales, and Peru. This range is extremely similar to that of Feresa attenuata. There have also been reports by Mignucci et al. (1998) of Peponocephala electra in the Caribbean sea. Other sources report individuals seen as far out of the typical range as southern Japan, Cornwall in England, Cape Province in South Africa, and Maryland in USA. These individuals most likely come from populations in adjacent warmer waters and represent extreme cases of migration.

Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

  • Gray, J. 1871. The Catalogue of Seals and Whales. London, England: Taylor and Francis.
  • Dutton, E. 1981. Whales of the World. New York, NY: Elsevier-Dutton Publishing Co Inc.
  • Jonsgard, A. e. 1968. The Whale. New York, NY: Simon and Schuster.
  • Perryman, W. 2002. Encyclopedia of Marine Mammals: Melon-headed whale - Peponocephala electra. San Diego, CA: Academic Press.
  • 2009. "Melon-Headed Whale - MarineBio.org" (On-line). Peponocephala electra. Accessed March 29, 2009 at http://marinebio.org/species.asp?id=417.
  • Culik, B. 2000. "Convention of Migratory Species (CMS): Whales and Dolphins" (On-line). Peponocephala electra. Accessed April 01, 2009 at http://www.cms.int/reports/small_cetaceans/data/P_electra/p_electra.htm.
  • Jefferson, T., N. Barros. 1997. Mammalian Species: Peponocephala electra. American Society of Mammalogists, 553: 1-6. Accessed April 05, 2009 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-553-01-0001.pdf.
  • Jefferson, T., S. Leatherwood, M. Webber. 1994. "FAO species identification guide. Marine mammals of the world." (On-line pdf). Peponocephala electra. Accessed April 02, 2009 at ftp://ftp.fao.org/docrep/fao/009/t0725e/t0725e20.pdf.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Range Description

Melon-headed whales have a pantropical distribution (Perryman 2002). The distribution coincides almost exactly with that of the pygmy killer whale in tropical/subtropical oceanic waters between about 40°N and 35°S (Jefferson and Barros 1997). A few high-latitude strandings are thought to be extralimital records, and are generally associated with incursions of warm water. These include specimens from Cornwall in England, Cape Province in South Africa, and Maryland, USA (Perryman et al. 1994; Rice 1998).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

occurs (regularly, as a native taxon) in multiple nations

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

National Distribution

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Global Range: Worldwide in tropical and subtropical waters (Jefferson and Barros 1997); reported as abundant only in Phillipine Sea, apparently rare elsewhere (Leatherwood and Reeves 1983). See Tomich (1986) for records off Hawaii. Recorded from Maryland and Texas (Barron and Jefferson 1993).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

in tropical and subtropical oceanic waters between 40ºN and 35ºS
  • North-West Atlantic Ocean species (NWARMS)
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Melon-headed whales are mostly dark grey, with a faint, darker gray cape that narrows at the head on the dorsal side. Often, they have a distinct dark eye patch that widens as it extends from the eye toward the melon. The lips are often white. Additionally, white or light grey areas are common in the throat region, from the blowhole to the top of the melon, and on the ventral side. The bodies of melon-headed whales are shaped like torpedos and are similar in size to pygmy killer whales, making it difficult to distinguish between the two in the field. The head of Peponocephala electra is shaped like a rounded cone, but lacks the clearly defined beak often seen in dolphins. The beak is longer and more slender than that of dolphins and it lacks the typical saddle or cape markings seen in many dolphins. The head is narrow and tapers, but the bump of the melon gives it a curved profile. The flippers are relatively long, estimated to be about 20% of the body length. They are smoothly curved and sharply pointed at the end. This creates an obvious distinction from the rounded flippers of pygmy killer whales. The dorsal fins of P. electra are distinct, curved in the middle of the back with a pointed tip, and shaped very much like the dorsal fin of bottlenose dolphins. Additionally, P. electra has 82 vertebrae, the first 3 are fused together. Melon-headed whales have 20 to 25 teeth in each upper toothrow, compared to 8 to 13 in pygmy killer whales. The teeth of P. electra are small and slender while those of pygmy killer whales are larger and more robust. This difference in dentition is the key identifier between pygmy killer whales and melon-headed whales.  Peponocephala electra is small to medium sized, averaging 2.6 meters in length in both males and females (no sexual dimorphism exists). The maximum length is about 2.75 meters, and the average length at birth is estimated to be 1 to 1.12 meters. The average weight is 228 kg (maximum 275 kg). At birth, the average young weights about 15 kg. The basal metabolic rate of Peponocephala electra is not known. In the wild, melon-headed whales have a lower fin, no patch on the chin, and a pointed, rather than rounded, flipper compared to pygmy killer whales. Melon-headed whales look around with their head out of the water, but do not sit up as high as other species. Nevertheless, it is difficult to distinguish melon-headed whales from pygmy killer whales.

Range mass: 275 (high) kg.

Average mass: 228 kg.

Range length: 1.43 to 2.75 m.

Average length: 2.6 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Size

Length: 270 cm

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Size in North America

Length:
Range: 2.1-2.7 meters

Weight:
Range: 160-208 kg
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution

Source: Smithsonian's North American Mammals

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Type Information

Type for Peponocephala electra (Gray, 1846)
Catalog Number: USNM A4108
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Sex/Stage: Unknown;
Preparation: Partial Skull
Year Collected: 1841
Locality: Hilo Bay, Hawaii, Hawaiian Islands, North Pacific Ocean
  • Type: Peale. 1848. U.S. Expl. Exped., 8. 32, pl. 6.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

The distribution of the rare, reported sightings of melon-headed whales suggest that they are found primarily in equatorial and subtropical waters from the continental shelf seaward. They seem to be found in deeper waters.

Habitat Regions: tropical ; saltwater or marine

Aquatic Biomes: pelagic

  • Mackintosh, N. 1965. The Stocks of Whales. Larkhall, Bath: Coward & Gerrish LTD..
  • Rice, D. 1998. Marine mammals of the world: systematics and distribution. Society for Marine Mammalogy, 4: 1-2.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat and Ecology

Habitat and Ecology
Most sightings are from the continental shelf seaward, and around oceanic islands; they are rarely found in temperate waters. However, they do occur in some nearshore areas where deep water approaches the coast (see Watkins et al. 1997; Wang et al. 2001a, b). In the eastern tropical Pacific, the distribution of reported sightings suggests that the oceanic habitat of this species is primarily in the upwelling modified and equatorial waters (Perryman et al. 1994).

Little is known of the diet of this species, though they are known to feed on several species of squid, shrimp and small fish.

Systems
  • Marine
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat Type: Marine

Comments: Pelagic, seaward from continental shelf and around oceanic islands; stays mainly in equatorial waters (Leatherwood and Reeves 1983).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Depth range based on 72 specimens in 1 taxon.
Water temperature and chemistry ranges based on 67 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 20.220 - 29.248
  Nitrate (umol/L): 0.038 - 7.245
  Salinity (PPS): 31.885 - 36.503
  Oxygen (ml/l): 4.491 - 5.288
  Phosphate (umol/l): 0.056 - 0.867
  Silicate (umol/l): 0.769 - 6.178

Graphical representation

Temperature range (°C): 20.220 - 29.248

Nitrate (umol/L): 0.038 - 7.245

Salinity (PPS): 31.885 - 36.503

Oxygen (ml/l): 4.491 - 5.288

Phosphate (umol/l): 0.056 - 0.867

Silicate (umol/l): 0.769 - 6.178
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Migration

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Trophic Strategy

Melon-headed whales typically feed on squid and small fish, but detailed information is lacking.

Animal Foods: fish; mollusks

Primary Diet: carnivore (Piscivore , Molluscivore )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Comments: Diet includes squids and various small fishes.

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

Peponocephala electra is an important predator of fish and squid in pelagic waters.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Little is known about predators of Peponocephala electra. Their medium to large size prevents them from attracting many predators, but perhaps large sharks or cetaceans would not be deterred by size alone. No specific predators are known.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

General Ecology

Gregarious; usually in herds of 150-1500; not infrequently associated with Fraser's dolphin, sometimes with spinner or spotted dolphin (Leatherwood and Reeves 1983).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Behavior

Melon-headed whales make sounds similar to the whistles and clicks of bottlenose dolphins.

Communication Channels: visual ; tactile ; acoustic

Perception Channels: visual ; tactile ; acoustic ; echolocation ; chemical

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Expectancy

Little is known about the lifespan or longevity of Peponocephala electra. The longest known lifespan in the wild is over 30 years, but the exact age is not known. There are no individuals in captivity, nor have there ever been.

Range lifespan

Status: wild:
30+ (high) years.

Typical lifespan

Status: wild:
20 to 30+ years.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Lifespan, longevity, and ageing

Maximum longevity: 47 years (wild)
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Reproduction

Nothing is known about the mating systems of Peponocephala electra or its close relatives.

Little is known about the reproduction of Peponocephala electra. Little or nothing is known about the breeding habits, breeding season, or breeding interval of melon-headed whales. Calving appears to peak in either early spring in the low latitudes of both hemispheres or in July and August in higher latitudes, but it seems calves are born year round and most data are inconclusive. Nothing is known of the birthing habits of melon-headed whales (their close relatives, pygmy killer whales, generally have only 1 calf). The length of gestation is not known, but probably about 12 months. Mass at birth is estimated to be between 10 and 15 kg, averaging around 12 kg. Nothing is known about the time to weaning specifics or independence. It is estimated that maturity is reached by about 4 years of age for both males and females.

Breeding interval: Nothing is known about the breeding habits of the melon-headed whale.

Breeding season: The exact breeding season is unknown. Calving appears to peak in either early spring in the low latitudes of both hemispheres or in July and August in higher latitudes, but it seems calves are born year round and most data is inconclusive.

Average gestation period: 12 months.

Average age at sexual or reproductive maturity (female): 4 years.

Average age at sexual or reproductive maturity (male): 4 years.

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

Average gestation period: 365 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)

Sex: male:
2465 days.

Average age at sexual or reproductive maturity (female)

Sex: female:
4290 days.

Little is known of the parental habits of Peponocephala electra, but it is assumed that mothers care for and nurse her young until they reach independence. As in other whale species, young are capable of swimming soon after birth.

Parental Investment: precocial ; 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)

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

In the Southern Hemisphere, births and late-term pregnant females have been recorded in July-August (Leatherwood and Reeves 1983).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Barcode data: Peponocephala electra

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Statistics of barcoding coverage: Peponocephala electra

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

Peponocephala electra is categorized as a species of “least concern” by the IUCN Red List. A taxon is “least concern” when it is considered widespread and abundant. Melon-headed whales are classified by CITES as an Appendix II species. They are not hunted specifically, but are accidentaly caught in fishing nets or occasionally hunted by fisheries in coastal Japan. Peponocephala electra is not listed on the other conservation sites.

US Federal List: no special status

CITES: appendix ii

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

  • International Union for Conservation of Nature and Natural Resources. 2008. "The IUCN Red List of Threatened Species" (On-line). Peponocephala electra. Accessed April 05, 2009 at http://www.iucnredlist.org/search.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

IUCN Red List Assessment


Red List Category
LC
Least Concern

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
Global trend or abundance data for this species are unavailable, however, abundance is at least 50,000. Threats that could cause widespread declines include high levels of anthropogenic sound, especially military sonar and seismic surveys, and localized competition with fisheries. The combination of the high global abundance and a large pan-tropical range with possible declines driven by more localized threats is believed sufficient to rule out a 30% global reduction over three generations (criterion A).

History
  • 1994
    Insufficiently Known
    (Groombridge 1994)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

National NatureServe Conservation Status

United States

Rounded National Status Rank: NU - Unrankable

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

NatureServe Conservation Status

Rounded Global Status Rank: G4 - Apparently Secure

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

Population
This species is relatively common in some areas of its range, such as parts of the Philippines, and is regularly seen in waters around the Hawaiian Islands and around some archipelagos in the western tropical Pacific (such as the Tuamotus-Marquesas Islands). Only a few abundance estimates are available, however.

There are estimates of 45,400 (CV=47%) animals in the eastern tropical Pacific (Wade and Gerrodette 1993); 3,451 (CV = 55%) in the Gulf of Mexico (Mullin and Fulling 2004); 2,947 animals (CV = 111%) in Hawaii (Barlow 2006); and 921 (CV = 80%) in the eastern Sulu Sea, Philippines (Dolar et al. 2006). Photo-identification data from the Hawaiian Islands indicate some site fidelity, with repeated re-sightings of individuals, although movements among the main Hawaiian Islands have been documented (Huggins et al. 2005; Baird pers. comm.).

There is no information on trends in the global abundance of this species.

Population Trend
Unknown
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Major Threats
Although there is considerable controversy regarding the absolute level of declines, there is good evidence of large-scale reductions in many predatory fish populations (e.g., Baum et al. 2003; Sibert et al. 2006) and over-fishing and collapse of several important “prey” fish stocks world-wide (e.g., Jackson et al. 2001). The effects of such fish population reductions and subsequent ecosystem changes on world-wide populations of melon-headed whales are unknown but could result in population declines.

Predicted impacts of global climate change on the marine environment may affect melon-headed whales, although the nature of impacts is unclear (Learmonth et al. 2006).

Although no regular, large hunts are known, this species is taken occasionally in the subsistence fishery for small cetaceans near the island of St. Vincent in the Caribbean, in Taiwan and in the Japanese dolphin drive fishery. They continue to be taken in a long-lived and well-established harpoon fishery for sperm whales and various small cetaceans near Lamalera, Indonesia. Four melon-headed whales were taken during the 1982 fishing season. Small-boat fisherman also occasionally harpoon or net this species near Sri Lanka and in the Philippines (Jefferson et al. 1993; Perryman et al. 1994). Dolar et al. (1994) investigated the fisheries for marine mammals in central and southern Visayas, northern Mindanao and Palawan, Philippines. Hunters at several sites took melon-headed whales for bait or human consumption. Whales are taken by hand harpoons or, increasingly, by togglehead harpoon shafts shot from modified, rubber-powered spear guns. Around 800 cetaceans of various species are taken annually by hunters at the seven sites, mostly during the inter-monsoonal period of February-May.

Mortality from incidental captures in the purse-seine fishery for yellowfin tuna in the eastern tropical Pacific will probably continue at a very low level (Perryman et al. 1994). Information is scant, but at least small numbers of these pelagic animals are known to be taken in nets throughout the tropics. Especially considering that bycatch of small cetaceans in general is a large and growing problem in Asia (Perrin et al. 2002), low numbers of reports may be misleading. However, no particular conservation problem has been identified.

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). An anomalous movement of melon-headed whales into a bay in Hawaii was associated with military sonar (Southall et al. 2006), and the frequency of mass stranding events for this species have increased in the last 30 years (Brownell et al. 2006).

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.

Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
The species is listed in Appendix II of CITES. Research is needed to assess the impacts of potential threatening processes.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

There are no known adverse effects of Peponocephala electra on humans. Since they are so uncommon and swim in such deep water, it is rare that they collide with a boat, get tangled in nets, or disrupt fisheries.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Melon-headed whales are important members of pelagic ecosystems. Humans occasionally catch them in fisheries, especially near the island of St. Vincent in the Caribbean, in the Japanese dolphin drive fishery, near Lamalera, Indonesia, near Sri Lanka, and in the Philippines. However, the number of Peponocephala electra taken each year is small. For instance, during the 1982 fishing season only 4 melon-headed whales were taken. Once caught, melon-headed whales are used for bait or for consumption. These whales are typically caught and killed with hand harpoons or toggle-head harpoon shafts shot from spear guns.

Positive Impacts: food

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Uses

Comments: Has been harvested in small numbers off Japan (Leatherwood and Reeves 1983).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Risks

IUCN Red List Category

Least Concern (LC)
  • IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Melon-headed whale

Melon-headed whale!<-- This template has to be "warmed up" before it can be used, for some reason -->

The melon-headed whale (species Peponocephala electra; other names are many-toothed blackfish and electra dolphin) is a cetacean of the oceanic dolphin family (Delphinidae). It is closely related to the pygmy killer whale and pilot whale, and collectively these dolphin species are known by the common name blackfish. It is also related to the false killer whale.[1] The melon-headed whale is widespread throughout the world's tropical waters, although not often seen by humans because it prefers deep water.[2]

Contents

Taxonomy

Its inaccessibility limits scientiific understanding of this species. Most scientific data has come from mass strandings. Until 1966 it was classified in the genus Lagenorhynchus. Scientists then gave it a unique genus, 'Peponocephala'.

Description

The Melon-head has a body shape rather like a torpedo. Its head is a rounded cone giving the animal its common name. The body is more or less uniformly light grey except for a dark grey face – sometimes called the "mask". The flippers are long and pointed. The dorsal fin is tall with a pointed tip – reminiscent of its cousin the Orca. When viewed in profile its head is not as rounded as the Pygmy Killer and this may aid identification.

This whale is capable of very fast swimming, particularly when startled. In flight, it often makes short low jumps clear of the sea surface, splashing lots water. Melon-heads usually gather in large numbers (at least 100 and possibly as many as 1,000 on rare occasions) and sometimes strand together.

The Melon-head weighs 10–15 kilograms (22–33 lb) at birth and is 1 meters (3 ft) long. An adult grows up to 3 meters (10 ft) long and weighs over 200 kilograms (441 lb). The whales' lifespan is at least 20 years and probably more than 30 years for females.

Their primary diet is squid.

Hawaiian melon-heads spend much of their daytime at the surface resting.[1]

Population and distribution

The melon-headed whale lives far from shore in all the world's tropical and sub-tropical oceans. At the northern fringes of its range it may also be found in temperate waters. Individuals have been sighted off the southern coast of Ireland. Ordinarily, however, the Melon-head is found beyond the continental shelf between 20° S and 20° N. Hawaii and Cebu, in the Philippines, are good sites for seeing the whale because the continental shelf there is narrow. Although no specific data exists, the species is unlikely to be migratory, in common with animals in its subfamily.

On February 10,2009, over 300 melon-headed whales were spotted off the shallow waters of Bataan, in the Philippines.[3] Local residents and volunteers guided the dolphins back to deeper waters. Although no definite explanation has been provided for the dolphins' behaviour, it's been noted that two of the three dead dolphins had damaged ear drums.[4]

In Hawaii, group sizes are variable, ranging from a single animal to pods of 800, but typically they are found in relatively large groups (median = 287 individuals).There appear to be two Hawaiian populations a large, deep water group that moves frequently among the islands and a small, shallow water population that stays near the island of Hawaiʻi. Melon-headed whales whales are closely related to false killer whales, short-finned pilot whales and pygmy killer whales. Hawaiian melon-heads spend much of their daytime at the surface resting.[1]

References

  • 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). Peponocephala electra. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 24 March 2009. Database entry includes justification for why this species is of least concern
  • National Audubon Society: Guide to Marine Mammals of the World ISBN 0-375-41141-0
  • Encyclopedia of Marine Mammals ISBN 0-12-551340-2

Notes

  1. ^ a b c "Melon-headed whales in Hawai‘i". Cascadia Research Institute. September, 2010. http://www.cascadiaresearch.org/hawaii/melonheadedwhale.htm. Retrieved October,2010. 
  2. ^ Froese, Rainer, and Daniel Pauly, eds. (2006). "Peponocephala electra" in FishBase. April 2006 version.
  3. ^ Hundreds of Dolphins Sighted in Bataan-waters
  4. ^ Melon-head stranding
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Names and Taxonomy

Taxonomy

Comments: Historically included in the genus Lagenorhynchus. Monotypic (Jefferson and Barros 1997).

Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© NatureServe

Source: NatureServe

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!