Lagenodelphis hosei Fraser,
English: Fraser's dolphin
Spanish: Delfín de Fraser
French: Dauphin de Fraser
Lagenodelphis hosei © Würtz-Artescienza
The body of Fraser's dolphin is stocky, the beak short but distinct
and the dorsal fin small, triangular and slightly falcate. The flippers
and flukes are also comparatively small. The striking colouration
varies with age and sex: a distinctive black stripe extending from
the eye to the anus is absent or faint in juveniles, wider and thicker
in adult males and variable in adult females. A similar pattern
is observed with the facial stripe or "bridle". The back
of L. hosei is brownish grey, the lower side cream-coloured
and the belly is white or pink. The largest male recorded was 2.7m
and the largest female 2.6m long. Large males can weigh up to 210
kg (Dolar, 2009).
The one species in this genus was not recognized until 1956, when
it was described from a single skull which had been picked up on
a beach in Sarawak in 1895. It remained unknown to science as a
living animal until 1971, when the species was "rediscovered".
Once its external features became known, it turned out that tuna
fishermen in the eastern tropical Pacific were already familiar
with it (Rice, 1998). Based on cytochrome b mtDNA it is more closely
related to Stenella, Tursiops, Delphinus, and Sousa than
to Lagenorhynchus, while skull morphology shows similarities
with D. delphis, S. longirostris, S. coeruleoalba
and S. clymene (Dolar, 2009).
L. hosei is pantropical and ranges north to the Gulf of
Mexico, Islas Canarias, West Africa (van Waerebeek et al. 2000)
Sri Lanka, Taiwan, southern Honshu, and Jalisco in Mexico and south
to Uruguay and Brasil, Natal, Queensland, and Peru (Rice, 1998).
Distribution of Lagenodelphis hosei: deep tropical
and warm temperate waters of the Pacific,
Atlantic and Indian Oceans between 30°S and 30°N (Hammond
et al. 2008;
© IUCN; Enlarge
The distribution of this species is poorly known.
It appears to be most common near the equator in the eastern tropical
Pacific and at the southern end of Bohol Strait in the Philippines.
It seems to be relatively scarce in the Atlantic Ocean, where it
is known from the Lesser Antilles and the Gulf of Mexico (e.g. Mignucci-Giannoni
et al. 1999) and recently from Venezuela (Bolaños and Villarroel-Marín,
L. hosei may range across the Indian Ocean,
with confirmed sightings from the east coast of South Africa, Madagascar,
Sri Lanka, and Indonesia. It also occurs away from the equator as
far north as Taiwan and Japan and, in small numbers, off Australia
(Perrin et al. 1994). Recently (Weir et al. 2008), the species was
identified at sea and from strandings off Angola, Ghana and Nigeria,
confirming southern and eastern distribution limits for the species
within the Atlantic Ocean. Dolar et al. (1997) reported sightings
between the Philippines and Malaysia, which, however, were so infrequent
that they did not allow estimation of population density.
Strandings in temperate areas (Britanny in France, Victoria in Australia,
and Uruguay) may represent extralimital forays connected with temporary
oceanographic anomalies such as the world-wide El Niño phenomenon
in 1983-84, during which a mass stranding occurred in France (Perrin
et al. 1994). Bones et al. (1998) reported a stranding on the coast
3. Population size
Estimates of abundance are only known for a few areas. They include
289,500 (CV = 0,34) Fraser's dolphins in the eastern tropical Pacific
(Wade and Gerodette, 1993). In the Eastern Sulu Sea, Dolar et al.
(2006) estimated a total abundance of 13,500 (CV = 0,26). A 2002
shipboard line-transect survey of the entire Hawaiian Islands EEZ
resulted in an abundance estimate of 10,226 (CV=1.11) Fraser's dolphins
(Barlow 2006). This is currently the best available abundance estimate
for this stock (Caretta et al. 2008). Current population size in
the US Atlantic is unknown (Waring, 2007).
4. Biology and Behaviour
Habitat: This is typically a high-seas animal; it has not
been observed close to shore in shallow water. E.g., off Angola
and Nigeria. all records of Fraser's dolphins (Weir et al. 2008)
occurred in deep water (>1000 m), and in the Sulu Sea , Philippines,
and off the coast of Mexico, sighting rates are also highest at
these water depths. However, it may approach very close to shore
(100m) of some islands surrounded by deep water, e.g. Lesser Antilles,
Indonesia and Philippines (Dolar, 2009).
In the eastern tropical Pacific, in equatorial-southern subtropical
surface water and other waters typified by upwelling and generally
more variable conditions, it forms part of a cetacean community
that also includes Physeter
coeruleoalba and Peponocephala
electra. Off South Africa, records are associated with the
warm Agulhas Current that moves south in the summer (Perrin et al.1994
and refs. therein).
This community is more or less complementary in occurrence to another
group of species, found primarily in so-called tropical surface
water, where a stable, shallow mixed layer and thermocline ridging
are dominant features, that includes Stenella
longirostris and Steno
bredanensis (Perrin et al.1994 and refs. therein).
Behaviour: Analysis of prey suggests that Fraser's dolphin
is a deep diver, hunting at depths of at least 250-500m (Carwardine,
1995) or more, and myoglobin concentrations in muscle reach 7.1
g Mb / 100 g, similar to values recorded from deep-diving weddell
seals (Leptonychotes weddellii) and bottlenose whales (Hyperoodon
ampullatus; Dolar, 2009). In some areas, it is considered
shy and difficult to approach; in others it is a bit more approachable.
It does not bowride in the eastern tropical Pacific, but it does
in most other areas. Running herds create a great deal of white
water (Jefferson et al. 1993).
Reproduction: The life history of Fraser's dolphin was examined
by Amano et al. (1996) based on 108 specimens from a school captured
by the drive fishery in Japan. The sex ratio was approximately 1:1.
The annual ovulation rate was 0.49. The estimated neonatal length
(110 cm) predicts a gestation period of about 12.5 mo. and calving
peaks in spring and probably also in fall. The calving interval
was estimated to be about 2yr. Life history parameters are similar
to those of the striped and pantropical spotted dolphins, but reproductive
rate of this species may be lower than that of other pelagic delphinids,
if the observed shorter longevity is real.
Schooling: Herds tend to be large, consisting of hundreds
or even thousands of dolphins, often mixed with other species, such
as melon-headed whales (Peponocephala electra), short-finned
pilot whales (Globicephala macrorhynchus), Risso's dolphins
(Grampus griseus), spinner dolphins (Stenella longirostris)
pantropical spotted dolphins (S. attenuata), bottlenose dolphinss
truncatus) and sperm whales (Perrin et al.1994 and refs.
therein; Dolar, , 2009). Weir et al. (2008) observed a pod of 150
probable Fraser's dolphins 130 km south of Nigeria off Nigeria and
schools of 120 and 60 animals 170 km and 140 km respectively off
the coast of Angola.
Food: In the eastern Pacific, Fraser's dolphin feeds on
mesopelagic fish, shrimps and squids. It rarely associates there
with bird flocks or tuna schools, which correlates well with the
absence of surface-dwelling prey from its diet. In other regions,
e.g. the southern Indian Ocean and the western Pacific, it may also
feed far below the surface. The stomachs of animals stranded in
Brittany contained only the remains of fish (4-24cm long; four species)
and the cephalopod Sepia sp., indicating benthic or mesopelagic
feeding preferences (Perrin et al. 1994). Santos and Haimovici (1998)
reported on the preference for loliginid squids in the diet of L.
hosei stranded in southern Brazil.
Dolar et al. (2003) examined the stomach contents of Fraser dolphins
in the Sulu Sea and found mesopelagic fishes, particularly myctophids
(mainly Ceratoscopelus warmingi, Diaphus spp. and
Myctophum asperum), to be equally important as mesopelagic
cephalopods (Abraliopsis, Onychoteuthis, Histioteuthis, and
Chiroteuthis), and crustaceans (Notostomos elegans, Acanthephyra
quadrispinosa, and Acanthephyra carinata). Vertical distributions
of the prey items summarized from published literature indicate
that Fraser's dolphins cover a wide vertical foraging range, from
near the surface to probably as deep as 600 m. Watkins et al. (1994)
reported on co-operative hunting techniques observed in the Caribbean.
There are no detailed reports on migratory behaviour, although
this pelagic species regularly approaches islands where it is captured
for human consumption (see below).
Direct catch: Small numbers of Fraser's dolphins are taken
in local subsistence harpoon fisheries in the Lesser Antilles, Indonesia,
the Philippines and probably elsewhere in the Indopacific. A few
are taken in drive fisheries in Taiwan and Japan (Perrin et al.
1994 and refs. therein). Dolar et al. (1994) investigated directed
fisheries for marine mammals in central and southern Visayas, northern
Mindanao and Palawan, Philippines, from archived reports and visits
to sites where such fisheries are conducted. Some of the hunters
take only dolphins, for bait or human consumption, and the species
taken include Fraser's dolphins. These are taken by hand harpoons
or, increasingly, by togglehead harpoon shafts shot from modified,
rubber-powered spear guns. Around 800 cetaceans are taken annually
by hunters at the seven sites, mostly during the inter-monsoon period
of February-May. Dolphin meat is consumed or sold in local markets
and some dolphin skulls are cleaned and sold as curios (Dolar et
Incidental catch: Some are killed incidentally in the tuna
purse-seine fishery in the eastern tropical Pacific: 26 were estimated
taken during the period 1971-75 (Gerrodette and Wade 1991). A few
are also taken in gill nets in Sri Lanka, the Philippines, and likely
in other tropical gillnet fisheries as well. Some are killed by
anti-shark nets (Perrin et al. 1994 and refs. therein; Dolar et
al. 1999; Cockroft, 1990).
More recently, Weir et al. (2008) monitoring bycatch at six artisanal
Ghanaian fishing ports between 1998 and 2000 found four Fraser's
dolphins comprising one adult, one juvenile and two calves at two
ports. Drift gillnets were identified as the probable cause of mortality
for at least two specimens.
Pollution: In an investigation on the global distribution
and toxicological impacts of
polychlorinated biphenyls (PCBs) on cetaceans, Minh et al. (2000),
found residues to be the highest in Fraser's dolphins collected
off Kii Peninsula, Japan, reflecting serious marine pollution by
PCBs in industrialized Asian countries. Values exceeded the levels
associated with immunosuppression in harbour seals.
Range states (Hammond et al. 2008):
American Samoa; Anguilla; Antigua and Barbuda; Argentina; Aruba;
Australia; Bahamas; Bangladesh; Barbados; Belize; Benin; Bermuda;
Brazil; Brunei Darussalam; Cambodia; Cameroon; Cayman Islands; China;
Colombia; Congo; Congo, The Democratic Republic of the; Cook Islands;
Costa Rica; Côte d'Ivoire; Cuba; Djibouti; Dominica; Dominican
Republic; Ecuador; El Salvador; Equatorial Guinea; Fiji; French
Guiana; French Polynesia; Gabon; Gambia; Ghana; Grenada; Guam; Guatemala;
Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; Hong Kong; India;
Indonesia; Iran, Islamic Republic of; Jamaica; Japan; Kenya; Kiribati;
Liberia; Madagascar; Malaysia; Maldives; Marshall Islands; Mauritania;
Mexico; Micronesia, Federated States of; Morocco; Mozambique; Myanmar;
Namibia; Nauru; Netherlands Antilles; Northern Mariana Islands;
Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines;
Pitcairn; Puerto Rico; Saint Kitts and Nevis; Saint Lucia; Saint
Pierre and Miquelon; Saint Vincent and the Grenadines; Samoa; Senegal;
Sierra Leone; Singapore; Solomon Islands; Somalia; South Africa;
Sri Lanka; Suriname; Tanzania, United Republic of; Thailand; Timor-Leste;
Togo; Tonga; Trinidad and Tobago; United States; United States Minor
Outlying Islands; Uruguay; Venezuela; Viet Nam; Virgin Islands,
British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara;
On 16 December 1992 the Department of Agriculture of the Philippines
issued Fisheries Administrative Order No. 185, 'banning the taking
or catching, selling, purchasing, possessing, transporting and exporting
of dolphins'. The order did not stop dolphin and whale hunting but
seems to have decreased the sale of dolphin meat openly in the market.
Investigations are encouraged to ensure that these artisanal whale
fisheries operate within sustainable limits and do not export products
illegally (Dolar et al. 1994). This recommendation can also be extended
to other populations of Fraser's dolphins.
For South American stocks, see further recommendations in Hucke-Gaete
(2000) in Appendix
1; for Southeast Asian stocks see general recommendations in
Perrin et al. (1996) in Appendix
The species is poorly known with respect to its distribution, migratory
behaviour and abundance and by-catch rates are poorly documented.
L. hosei is listed as "Least Concern" by the IUCN
(Hammond et al. 2008) . The southeast Asian populations are listed
in Appendix II of CMS. The species is listed in Appendix II of CITES.
· Amano M, Miyasaki N, Yanagisawa F (1996)
Life history of Fraser's dolphin, Lagenodelphis hosei, based
on a school captured off the Pacific coast of Japan. Mar Mamm Sci
· Barlow J (2006) Cetacean abundance in Hawaiian waters estimated
from a summer/fall survey in 2002. Mar Mamm Sci 22: 446-464
· Bolaños J, Villarroel-Marín A (2003) Three
new records of cetacean species for Venezuelan waters. Carib J Sci
· Bones M, Neill B, Reid B (1998) Fraser's dolphin (Lagenodelphis
hosei) stranded in South Uist: first record in U.K. waters.
J Zool 246: 443-486.
· Carretta JV, Forney KA, Lowry MS, Barlow J, Baker J, Johnston
D, Hanson B, Muto MM, Lynch D, Carswell L (2008) U.S. Pacific Marine
mammal Stock Assessments: 2008. NOAA-TM-NMFS-SWFSC-434
· Carwardine M (1995) Whales, dolphins and porpoises. Dorling
Kindersley, London, UK, 257 pp.
· Cockroft VG (1990) Dolphin catches in the Natal (South
Africa) shark nets, 1980 to 1988. S Af J Wildl Res 20: 44-51.
· Dolar ML (2009) Fraser's Dolphin - Lagenodelphis hosei.
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B, Thewissen JGM, eds.) Academic Press, Amsterdam, pp. 469- 471.
· Dolar MLL, Leatherwood SJ, Wood CJ, Alava MNR, Hill CL,
Aragones LV (1994) Directed fisheries for cetaceans in the Philippines.
Rep Int Whaling Comm 44: 439- 449.
· Dolar MLL, Suarez P, Ponganis PJ, Kooyman GL (1999) Myoglobin
in pelagic small cetaceans. J Exp Biol 202: 227-236.
· Dolar MLL, Perrin WF, Taylor BL, Kooyman GL (2006) Abundance
and distributional ecology of cetaceans in the central Philippines.
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· Dolar MLL, Perrin WF, Yaptinchay ASP, Jaaman SABH, Santos
MD, Alava MN, Suliansa MSB (1997) Preliminary investigation of marine
mammal distribution, abundance, and interactions with humans in
the southern Mulu sea. Asian Mar Biol 14: 61-81.
· Dolar MLL, Walker, WA, Kooyman GL, Perrin WF (2003) Comparative
feeding ecology of spinner dolphins (Stenella longirostris)
and Fraser's dolphins (Lagenodelphis hosei) in the Sulu Sea.
Mar Mamm Sci 19: 1-19.
· Gerrodette T, Wade PR (1991) Monitoring trends in dolphin
abundance in the eastern Tropical Pacific: Analysis of 1989 data.
(IWC SC/42/SM-42). Rep Int Whal Comm 41: 511-515.
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· Hucke-Gaete R ed. (2000) Review on the conservation status
of small cetaceans in southern South America. UNEP/CMS Secretariat,
Bonn, Germany, 24 pp.
· Jefferson TA, Leatherwood S, Webber MA (1993) FAO Species
identification guide. Marine mammals of the world. UNEP/FAO, Rome,
· Mignucci Giannoni AA, Montoya Ospina RA, Perez Zayas JJ,
Rodriguez Lopez MA, Williams EHJ (1999) New records of Fraser's
dolphin (Lagenodelphis hosei) for the Caribbean. Aquat Mamm
· Minh TB, Nakata H, Watanabe M, Tanabe S, Miyazaki N, Jefferson
TA, Prudente M, Subramanian A (2000) Isomer-specific accumulation
and toxic assessment of polychlorinated biphenyls, including coplanar
congeners, in Cetaceans from the North Pacific and Asian coastal
waters. Arch Environ Contam Toxicol 39: 398-410.
· Perrin WF, Dolar MLL, Alava MNR (1996) Report of the workshop
on the biology and conservation of small cetaceans and dugongs of
Southeast Asia. East Asia Seas Action Plan. UNEP(W)/EAS WG. 1/2,
Bangkok, Thailand, 101 pp.
· Perrin WF, Leatherwood S, Collet A (1994) Fraser's dolphin
- Lagenodelphis hosei Fraser. In: Handbook of marine mammals
(Ridgway SH, Harrison SR eds.) Vol. 5: The first book of dolphins.
Academic Pres, London, pp. 225-240.
· Rice DW (1998) Marine mammals of the world: systematics
and distribution. Society for Marine Mammalogy, Spec Publ 4 , Lawrence,
· Santos RA, Haimovici M (1998) Cephalopods in the diet of
marine mammals stranded or incidentally caught along Southeast and
Southern Brazil (21° to 34°S). Copenhagen Denmark Ices,
· Van Waerebeek K, Ndiaye E, Djiba A, Diallo M, Murphy P,
Jallow A, Camara A, Ndiaye P, Tous P (2000) A survey of the conservation
status of cetaceans in Senegal, the Gambia and Guinea-Bissau. UNEP
/ CMS Secreta-riat, Bonn, Germany, 80 pp.
· Wade PR, Gerrodette T (1993) Estimates of cetacean abundance
and distribution in the eastern tropical Pacific. Rep Int Whal Comm
· Watkins W A, Daher M A, Fristrup K, Notarbartolo Di Sciara
G (1994) Fishing and Acoustic Behavior of Fraser's Dolphin (Lagenodelphis
hosei) near Dominica, Southeast Caribbean. Carib J Sci 30: 76-82.
· Waring GT, Josephson E, Fairfield CP, Maze-Foley K, editors.
2007. U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments
-- 2006. NOAA Tech Memo NMFS NE 201; 378 p
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K (2008) Records of Fraser's dolphin Lagenodelphis hosei
Fraser 1956 from the Gulf of Guinea and Angola. Afr J Mar Sci 30:
© Boris Culik (2010) Odontocetes.
The toothed whales: "Lagenodelphis hosei". UNEP/CMS
Secretariat, Bonn, Germany.http://www.cms.int/small-cetaceans
© Illustrations by Maurizio Würtz, Artescienza.
© Maps by IUCN.