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No Records
Occasional
Range

Map base conforms with ICES grid squares.

Basking Shark, Bone Shark, Elephant Shark, Hoe-Mother, Pélerin (Fr), 
Peregrino (Es).

Squalus maximus (Gunnerus, 1765), Halsydrus pontoppidani (Neill, 
1809), Tetroras angiova (Rafinesque, 1809), Squalus aunnerianus 
(Blainville, 1810), Squalus homianus (Blainville, 1810), Squalus 
pelegrinus (Blainville, 1810), Squalus peregrinus (Blainville, 1811), 
Squalus qunneri (Blainville, 1816), Squalus shavianus (Blainville, 1816), 
Scoliophis atlanticus (Anon., 1817), Squalus isodus (Macri, 1819), 
Squalus rostratus (Macri, 1819), Squalus elephas (LeSueur, 1822), 
Squalus rashleighanus (Couch, 1838), Squalus rhinoceros (Mitchell, 

COMMON NAMES

to be fairly dis-
junct with limited 
genetic exchange 
between popula-
tions. In the east 
Atlantic it is known 
from Russia and 
northern Norway, 
Iceland, the British 
Isles, all through the 
Mediterranean Sea 
and as far south as 
Senegal. It is also 
found in Namibia 
and South Africa. 
In the northwest 
Atlantic it is found 
from Canada to the 
northern Gulf of 
Mexico and in the 
southwest Atlan-

BS

K

VU

Text & Illustrations © Shark Trust 2009

Lateral View (

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Ventral View (

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Basking Shark

Cetorhinus maximus

N

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M

ED

NE A

TL:

EN

tic it is known from southern Brazil to southern Argentina and the 
Falkland Islands.

In the west Pacific it can be found in south Australia and New 

Zealand, further north in Japan, the Korean Peninsula, Taiwan and 
China. In the northeast Pacific It is known from the Gulf of Alaska to 
the Gulf of California, including the Aleutian Islands and further out, 
the Hawaiian Islands. In the southeast Pacific it can be found from 
Ecuador to southern Chile.
 

Currently only one species of Cetorhinidae is recognised but 

Siccardi (1960, 1961) suggested that there are four distinct species; C. 
maximus and C. rostratus in the North Atlantic and Mediterranean, C. 
normani in the western South Atlantic and C. maccoyi from southern 
Australia. While most authors disagree with this assessment it appears 
that due to limited genetic interchange between stocks, distinct 
sub-populations may exist. These could be a North Pacific population 
(with possible distinction between the northeast and northwest Pa-
cific), a North Atlantic population (with possible distinction between 
the northeast and northwest Atlantic and the Mediterranean Sea), a 
South American population (with possible distinction between the 
southwest Atlantic and the southeast Pacific), a South African popula-
tion (including Namibia) and an Australia-New Zealand population (if 
not separate) (Compagno, 2001).

The Basking Shark has a circumglobal distribution although it appears 

in DeKey, 1842), Squalus cetaceus (Gronow, 1854), Polyprosopus 
macer (Couch, 1962), Cetorhinus blainvillei (Brito Capello, 1870), 
Selachus pennantii (Cornish, 1885), Cetorhinus maccoyi (Barrett, 1933), 
Cetorhinus maximus forma infanuncula (Deinse and Adriani, 1953), 
Cetorhinus maximus normani (Siccardi, 1960), Halsydrus maximus 
(Gunnerus, 1765), Halsydrus maccoyi (Barrett, 1933), Cetorhinus 
rostratus (Macri, 1819), Cetorhinus normani (Siccardi, 1960)

SYNONYMS

DISTRIBUTION

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SIMILAR SPECIES

Carcharodon carcharias, White Shark
Lamna nasus, Porbeagle Shark

 

Basking Shark

Text & Illustrations © Shark Trust 2009

(Not to scale)

Supported by:

APPEARANCE

• Enormous gill slits which nearly encircle the head.
• Pointed snout.
• Huge subterminal mouth with minute hooked teeth.
• Eyes tiny relative to body size.
• Large first dorsal, pectoral and pelvic fins.
• Small second dorsal and anal fin.
• Lunate caudal fin with subterminal notch and lobe.
• Blackish to grey-brown, grey or blue-grey dorsally.
• Similar although sometimes lighter ventrally.
• Often irregular light blotches on underside of head and abdomen.
• Flanks sometimes with lighter striping and spots.
• To a maximum of 1,220cm but most do not exceed 980cm.

The Basking Shark is an enormous species which is difficult to confuse 
with any other in the northeast Atlantic. Its gills are elongated and 
stretch almost completely around the head. Whilst feeding these gills 
billow out in a way reminiscent of spinnakers, revealing the modified 

dermal denticle gill rakers used to filter the sea water for plankton. 
The pectoral fins are large and originate very close to the fifth gill slits. 
The first dorsal fin is large with a rounded tip and a free rear tip. It 
originates behind the pectoral fins with no overlap. The pelvic fins are 
large with straight edges and a fairly acute tip. The second dorsal fin 
is small and set slightly in front of the anal fin. The caudal fin is lunate 
with a strong subterminal notch and lobe (Compagno, 2001).

Dorsally it is normally grey although it can be blackish, grey-

brown or blue grey. Ventrally it is very similar although sometimes 
lighter. There is usually a pattern of light blotches on the underside of 
the head and abdomen and lighter striping and spots on the flanks. 
There are two reports of albino specimens from the North Atlantic 
(Knickle et al., Unknown). The maximum reported size of the Bask-
ing Shark is 1,220cm and the existence of 1,520cm long specimens 
has been hypothesised. Most adults do not exceed 980cm however 
(Compagno, 2001).

Cetorhinus maximus,
Basking Shark

Carcharodon carcharias, 
White Shark

Lamna nasus,
Porbeagle Shark

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Basking Shark 

Cetorhinus maximus

TEETH

The teeth are minute and hooked. There is a wide space on 
the centre of the upper jaw with only scattered teeth (Knickle 
et al., Unknown).

HABITAT

A coastal to oceanic species, the Basking Shark is normally 
encountered at or near the surface but has been recorded as deep 
as 1,264m (Gore et al., 2008). It is known to venture inshore to 
shallow bays, almost to the surf line, and is regularly sighted from 
land at certain times of the year. Records from the open ocean are 
rarer but aerial surveys and pelagic driftnet catches show that it 
is found over the oceanic basins. The majority of records from the 
United Kingdom, Japan and Newfoundland  are from water 8–14

o

in temperature, although most records from New England are in 
water from 11–24

o

C with most of these over 16

o

C. It seems to prefer 

ocean fronts where different masses of water meet and where 
plankton may flourish. These areas include headlands, islands and 
bays with strong tidal flow (Compagno, 2001).

DIET

The Basking Shark is a passive filter feeder, swimming with its 
mouth open and straining the water through its pharynx for 
plankton. Modified dermal denticles called gill rakers, coated in 
mucus secreted in the pharynx helps capture these organisms 
(Compagno, 2001). It varies in this respect from other filter feeding 
elasmobranchs (Rhincodon typus, Megachasma pelagios, Manta 
birostris, Mobula spp.) which actively pump seawater across their 
filtering mechanisms and as such, may take more active nektonic 
prey such as small schooling fish and crustaceans (Pauly, 2002). 
Compagno (2001) lists the main food items as small copepods 
(including calanids), barnacles, decapoda, stomatopod larvae and 
fish eggs (Compagno, 2001). The common name of the Basking 
Shark comes from the fact that whilst feeding it appears to be 
basking at the surface, its first dorsal fin fully exposed and its back 
partly exposed. Feeding in this way it has been estimated it can filter 
2,000 tons of water per hour (Knickle et al., Unknown).

As with other species in the family Lamnidae, the Basking Shark 
reproduces vivpariously with embryos nourished by a continuous 
supply of unfertilised ova, a process known as oophagy or 
oviphagy. Very little else is known as only one gravid female has 
been recorded, suggesting that these animals segregate from the 
general population. Gestation periods of 1–3.5 years have been 
proposed with estimates of the size at birth from 100–170cm (Pauly, 
2002; Martin, Unknown). It is believed that males reach maturity 
around 460–610cm in length at an age of 12–16 years. No data for 
female maturity or the longevity of either sex is available, although 
extrapolation from other Lamnoids would suggest a female 
maturity of around 20 years and an age of at least 50 years (Martin, 
Unknown).

REPRODUCTION

Text & Illustrations © Shark Trust 2009

ECOLOGY AND BIOLOGY

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COMMERCIAL IMPORTANCE

The Basking Shark was historically hunted for its liver oil and to a 
lesser extent its meat and fins. It is still sought for its large fins which 
are extremely valuable in the Asian fin trade. Traditionally its liver 
oil was processed for vitamin A, tanning leather and as lamp oil. It 
is still processed for its squalene which is used for medicinal and 
cosmetic purposes. In addition, the skin can be used for leather, the 
cartilage for medicinal use and the carcass can be processed into 
fishmeal (Compagno, 2001).

IUCN RED LIST ASSESSMENT

Vulnerable (2000).
Endangered in northeast Atlantic.

In the United Kingdom, the Basking Shark was first protected 
around the Isle of Man and later around Guernsey. In April 1998, 
it was listed on the Wildlife and Countryside Act (1981) and 
completely protected in British waters out to the 12 mile limit 
(Defra, 2007). A UK Biodiversity Action Plan for this species was 
implemented in 1999 (JNCC, 2007). 

In the Mediterranean, the Basking Shark was protected in 

Maltese waters in 1999. It is listed on Annex II (as an Endangered or 
Threatened species) of the Protocol of the Barcelona Convention for 
the Protection of the Mediterranean Sea, and on Appendix II of the 
Bern Convention on Conservation of European Wildlife and Natural 
Habitats. 

In the USA, the Basking Shark is fully protected from fisheries 

in Florida state waters and in Federal US Atlantic and Gulf waters 
by the US Marine Fisheries Service (Shark Trust, 2007). The Shark 
Finning Act (HR 5461) prohibits the landing or possession of fins 
without the entire shark carcass and since 1997 fishermen are 
prohibited from keeping 19 species of shark, including the Basking 
Shark. In New Zealand, the Basking Shark has some protection; 
targeted fishing is illegal, but sharks taken as bycatch may be landed 
(Shark Trust, 2007).

Since 2007, the EU has prohibited fishing for, retaining on 

board, transhipping or landing the Basking Shark by any vessel in 
EU waters or by an EU vessel anywhere. Norway has also banned 
directed fisheries for Basking Sharks and any live specimens taken 
as bycatch must be released. However dead and dying sharks 
caught as bycatch can still be landed and sold, severely limiting the 
effectiveness of the ban (CPOA Shark, 2009).

The Basking Shark is listed in Appendix II of the Convention 

on International Trade in Endangered Species (CITES), Annex B of 
the EU Wildlife Trade Regulation (No. 338/97) and it is also covered 
by the Convention on Migratory Species (CMS). Since 2004, it has 
been included in the Convention on the Protection of the Marine 
Environment of the North-East Atlantic (OSPAR) list of threatened 
and/or declining species (CPOA Shark, 2009).

•  Handle with care.
•  Enormous, powerful shark.
•  Abrasive skin.

 

Basking Shark

Text & Illustrations © Shark Trust 2009

Supported by:

THREATS, CONSERVATION, LEGISLATION

HANDLING AND THORN ARRANGEMENT

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COMPAGNO, L. J. V. 2001. Sharks of the World: An Annotated and 

Illustrated Catalogue of Shark Species Known to Date, Volume 
2; Bullhead, Mackerel and Carpet Sharks (Heterodontiformes, 
Lamniformes and Orectolobiformes). FAO. Rome, Italy.

DEFRA. 2007. Defra Wildlife and Countryside Act [on-line]. London: 

Defra. www.defra.gov.uk.

FOWLER, S.L. 2005. Cetorhinus maximus. In: IUCN 2010. IUCN Red 

List of Threatened Species.

GORE, M. A., ROWAT, D., HALL, J., GELL, F. R., ORMOND, R. F. 2008. 

Trans-Atlantic Migration and Deep Mid-Ocean Diving by 
Basking Sharks. Biology Letters, Vol. 4 (4): 395–398.

JNCC. 2007. UK Biodiversity Action Plans [on-line]. Peterborough: 

JNCC. www.ukbap.org.uk.

KNICKLE, C., BILLINGSLEY, L., DIVITTORIO, K. Unknown. Basking 

Shark. Florida Museum of Natural History. www.flmnh.ufl.edu/
fish/.

MARTIN, R. A. Unknown. Biology of the Basking Shark (Cetorhinus 

maximus). Reefquest Centre for Shark Research. www.elasmo-
research.org.

PAULY, D. 2002. Growth and Mortality of the Basking Shark 

Cetorhinus maximus and their Implications for Management of 
Whale Sharks Rhincodon typus. p.199–208 In: Fowler, S. L., Reid, 
T., Dipper, F. A, (Eds.) Elasmobranch Diversity: Conservation and 
Management. Proceedings of an International Seminar and 
Workshop held in Sabah, Malaysia. Occasional Papers of the 
IUCN Survival Commission No. 25. Gland, Switzerland.

SHARK TRUST, 2007. Basking Shark Project. www.baskingsharks.

org.

REFERENCES

Basking Shark 

Cetorhinus maximus

Text & Illustrations © Shark Trust 2009

Text: Richard Hurst.
Illustrations: Marc Dando.

Citation
Shark Trust; 2010. An Illustrated Compendium of Sharks, Skates, Rays 
and Chimaera. Chapter 1: The British Isles and Northeast Atlantic. Part 
2: Sharks.

Any ammendments or corrections, please contact:
The Shark Trust
4 Creykes Court, The Millfields
Plymouth, Devon PL1 3JB

Tel: 01752 672008/672020

Email: enquiries@sharktrust.org

For more ID materials visit www.sharktrust.org/ID.

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