Wikipedia

Basking shark

(Redirected fromBasking sharks)
"Basking sharks" redirects here. For the band, seeBasking Sharks (band).

Thebasking shark(Cetorhinus maximus) is the second-largest livingsharkandfish,[4]after thewhale shark.It is one of threeplankton-eatingshark species, along with the whale shark andmegamouth shark.Typically, basking sharks reach 7.9 m (26 ft) in length. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in colour. Thecaudal finhas a strong lateral keel and a crescent shape. Other common names include bone shark, elephant shark, sailfish, and sunfish. InOrkney,it is called hoe-mother (contracted homer), meaning "the mother of thepiked dogfish".[5]

Basking shark
Temporal range:Miocene–Present[1]
The size of basking sharks at various stages of growth and maturity with a human for scale
CITESAppendix II(CITES)[3]
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Lamniformes
Family: Cetorhinidae
Genus: Cetorhinus
Blainville,1816
Species:
C. maximus
Binomial name
Cetorhinus maximus
(Gunnerus,1765)
Range of the basking shark
Synonyms
click to expand
  • Cetorhinus blainvilleiCapello, 1869
  • Cetorhinus maximus infanunculaDeinse & Adriani, 1953
  • Cetorhinus normaniSiccardi, 1961
  • Hanovera auratavan Beneden, 1871
  • Halsydrus pontoppidiani*Neill, 1809
  • Polyprosopus macerCouch, 1862
  • Scoliophis atlanticus*Anonymous, 1817
  • Selachus pennantiiCornish, 1885
  • Squalis gunneri*Blainville, 1816
  • Squalis shavianus*Blainville, 1816
  • Squalus cetaceusGronow, 1854
  • Squalus elephasLesueur, 1822
  • Squalus gunnerianusBlainville, 1810
  • Squalus homianusBlainville, 1810
  • Squalus isodusMacri, 1819
  • Squalus maximusGunnerus, 1765
  • Squalus pelegrinusBlainville, 1810
  • Squalus rashleighanusCouch, 1838
  • Squalus rhinoceros*DeKay, 1842
  • Squalus rostratusMacri, 1819
  • Tetraoras angiova*Rafinesque, 1810
  • Tetroras angiova*Rafinesque, 1810
  • Tetroras maccoyiBarrett, 1933
  • ----
  • * ambiguous synonym

The basking shark is acosmopolitanmigratoryspecies found in all the world's temperate oceans. A slow-movingfilter feeder,its common name derives from its habit of feeding at the surface, appearing to be basking in the warmer water there. It has anatomical adaptations for filter-feeding, such as a greatly enlarged mouth and highly developedgill rakers.Its snout is conical, and the gill slits extend around the top and bottom of its head. The gill rakers, dark and bristle-like, are used to catch plankton as water filters through the mouth and over the gills. The teeth are numerous and very small and often number 100 per row. The teeth have a single conical cusp, are curved backwards and are the same on both the upper and lower jaws. This species has the smallest weight-for-weight brain size of any shark, reflecting its relatively passive lifestyle.[6]

Basking sharks have been shown from satellite tracking tooverwinterin both continental shelf (less than 200 m or 660 ft) and deeper waters.[7]They may be found in either small shoals or alone. Despite their large size and threatening appearance, basking sharks are not aggressive and are harmless to humans.

The basking shark has long been acommercially importantfish as a source of food,shark fin,animal feed, andshark liver oil.Overexploitationhas reduced its populations to the point where some have disappeared and others need protection.[8]

Taxonomy

edit

The basking shark is the onlyextantmember of the familyCetorhinidae,part of the mackerel shark orderLamniformes.Johan Ernst Gunnerusfirst described the species asCetorhinus maximus,from a specimen found inNorway,naming it. The genus nameCetorhinuscomes from the Greekketos,meaning "marine monster" or "whale", andrhinos,meaning "nose". The species namemaximumis from Latin and means "greatest". Following its initial description, more attempts at naming included:Squalus isodus,in 1819 by Italian zoologist Saverio Macri (1754–1848);Squalus elephas,byCharles Alexandre Lesueurin 1822;Squalus rashleighanus,byJonathan Couchin 1838;Squalus cetaceus,byLaurens Theodorus Gronoviusin 1854;Cetorhinus blainvilleiby the Portuguese biologist Felix Antonio de Brito Capello (1828–1879) in 1869;Selachus pennantii,byCharles John Cornishin 1885;Cetorhinus maximus infanuncula,by Dutch zoologists Antonius Boudewijn Deinse (1885–1965) and Marcus Jan Adriani (1929–1995) in 1953; andCetorhinus maximus normani,by Siccardi in 1961.[9]

Evolutionary history

edit

The oldest known members of Cetorhinidae are members of the extinct genusKeasius,from the middleEoceneof Antarctica, the Eocene of Oregon and possibly the Eocene of Russia. Members of the modern genusCetorhinusappear during theMiocene,with members of the modern species appearing during the Late Miocene. The association ofPseudocetorhinusfrom the Late Triassic of Europe with Cetorhinidae is doubtful.[10]

Range and habitat

edit

The basking shark is a coastal-pelagicshark found worldwide inborealto warm-temperate waters. It lives around thecontinental shelfand occasionally entersbrackish waters.[11]It is found from the surface down to at least 910 m (2,990 ft). It prefers temperatures of 8 to 14.5 °C (46.4 to 58.1 °F) but has been confirmed to cross the much warmer waters at the equator.[12]It is often seen close to land, including in bays with narrow openings. The shark followsplanktonconcentrations in the water column, so it is often visible at the surface.[13]It characteristically migrates with the seasons.[14]

Anatomy and appearance

edit

The basking shark regularly reaches 7–8.5 m (23–28 ft) in length with some individuals reaching 9–11 m (30–36 ft).[15][16][17][18][19]The average length of an adult is around 7.9 m (26 ft) weighing about 4.65 t (4.58 long tons; 5.13 short tons).[15]Historical sightings suggest basking sharks around 12 m (39 ft) in length, including three basking sharks estimated at ~40fod(12.5 metres (41 ft)) and a one ~45 fod (14 metres (46 ft)) were reported between 1884 and 1905, but these visual estimates lack good evidence.[15][20][19][21]A 12.27 m (40.3 ft) specimen trapped in a herring net in theBay of Fundy,Canada, in 1851 has been credited as the largest recorded.[15][22]Its weight has been estimated at 16 t (16 long tons; 18 short tons).[23][15]A study looking at the growth and longevity of the basking shark suggested that individuals larger than ~10 m (33 ft) are unlikely.[24]This is the second-largest extant fish species, after the whale shark.[4]

Beached basking shark

They possess the typical sharklamniformbody plan and have been mistaken forgreat white sharks.[25]The two species can be easily distinguished by the basking shark's cavernous jaw, up to 1 m (3 ft 3 in) in width, longer and more obviousgillslits that nearly encircle the head and are accompanied by well-developedgill rakers,smaller eyes, much larger overall size and smaller average girth. Great whites possess large, dagger-like teeth; basking shark teeth are much smaller 5–6 mm (0.20–0.24 in) and hooked; only the first three or four rows of the upper jaw and six or seven rows of the lower jaw function. In behaviour, the great white is an active predator of large animals, not a filter feeder.

Other distinctive characteristics include a strongly keeledcaudal peduncle,highly textured skin covered inplacoid scalesand a mucus layer, a pointed snout—distinctly hooked in younger specimens—and a lunatecaudal fin.[26]In large individuals, thedorsal finmay flop to one side when above the surface. Colouration is highly variable (and likely dependent on observation conditions and the individual's condition): commonly, the colouring is dark brown to black or blue dorsally, fading to a dull white ventrally. The sharks are often noticeably scarred, possibly through encounters withlampreysorcookiecutter sharks.The basking shark's liver, which may account for 25% of its body weight, runs the entire length of the abdominal cavity and is thought to play a role inbuoyancyregulation and long-term energy storage.

Life history

edit
Head of a basking shark

Basking sharks do not hibernate and are active year-round.[7]In winter, basking sharks often move to deeper depths, even down to 900 m (3,000 ft) and have been tracked making vertical movements consistent with feeding on overwintering zooplankton.[27]

Surfacing behaviors

edit

They are slow-moving sharks (feeding at about 2 knots (3.7 kilometres per hour; 2.3 miles per hour))[28]and do not evade approaching boats (unlike great white sharks). They are not attracted tochum.

The basking shark is large and slow, but it canbreachjump entirely out of the water.[29]This behaviour could be an attempt to dislodge parasites orcommensals.[14]Such interpretations are speculative, however, and difficult to verify; breaching in large marine animals such as whales and sharks might equally well beintraspecificthreat displaysof size and strength.

Migration

edit

Argos systemsatellite tagging of 20 basking sharks in 2003 confirmed basking sharks move thousands of kilometres during the summer and winter, seeking the richest zooplankton patches, often alongocean fronts.[7][30]They shed and renew their gill rakers in an ongoing process, rather than over one short period.[31]

A 2009 study tagged 25 sharks off the coast ofCape Cod,Massachusetts,and indicated at least some migrate south in the winter. Remaining at depths between 200 and 1,000 metres (660 and 3,280 ft) for many weeks, the tagged sharks crossed the equator to reach Brazil. One individual spent a month near the mouth of theAmazon River.They may undertake this journey to aid reproduction.[12][32]

On 23 June 2015, a 6.1-metre-long (20 ft), 3,500-kilogram (7,716 lb) basking shark was caught accidentally by afishing trawlerin theBass straitnearPortland,Victoria,in southeastAustralia,the first basking shark caught in the region since the 1930s, and only the third reported in the region in 160 years.[33][34]The whole shark was donated to theVictoria Museumfor research, instead of the fins being sold for use inshark fin soup.[35][36]

While basking sharks are not infrequently seen in theMediterranean Sea[37]and records exist in theDardanelles Strait,[38]it is unclear whether they historically reached deeper basins ofSea of Marmara,Black SeaandAzov Sea.

Social behaviour

edit
A basking shark filter feeding

Basking sharks are usually solitary, but during summer months in particular, they aggregate in dense patches of zooplankton, where they engage in social behaviour. They can form sex-segregated shoals, usually in small numbers (three or four), but reportedly up to 100 individuals.[14]Small schools in theBay of Fundyand theHebrideshave been seen swimming nose to tail in circles; their social behaviour in summer months has been studied and is thought to represent courtship.[39]

Predators

edit

Basking sharks have few predators. White sharks have been reported to scavenge on the remains of these sharks.Killer whaleshave been observed feeding on basking sharks off California in the US and New Zealand.Lampreysare often seen attached to them, although they are unlikely to be able to cut through the shark's thick skin.

Diet

edit
Basking shark filter feeding atDursey Sound

The basking shark is a ramfeeder,filteringzooplankton,very small fish, andinvertebratesfrom the water with its gill rakers by swimming forwards with its mouth open. A 5-metre-long (16 ft) basking shark has been calculated to filter up to 500 short tons (450 t) of water per hour swimming at an observed speed of 0.85 metres per second (3.1 km/h; 1.9 mph).[31]Basking sharks are not indiscriminate feeders on zooplankton. Samples taken in the presence of feeding individuals recorded zooplankton densities 75% higher than adjacent non-feeding areas.[40]Basking sharks feed preferentially in zooplankton patches dominated by small planktonic crustaceans calledcalanoid copepods(on average 1,700 individuals per cubic metre of water). They will also feed on copepods of the generaPseudocalanusandOithona.[41]Basking sharks sometimes congregate in groups of up to 1,400 spotted along the northeastern U.S.[42]Samples taken near feeding sharks contained 2.5 times as manyCalanus helgolandicusindividuals per cubic metre, which were also found to be 50% longer. Unlike themegamouth sharkandwhale shark,the basking shark relies only on the water it pushes through its gills by swimming; the megamouth shark and whale shark can suck or pump water through their gills.[9]

Reproduction

edit

Basking sharks areovoviviparous:the developing embryos first rely on ayolksac, with noplacentalconnection. Their seemingly useless teeth may play a role before birth in helping them feed on the mother's unfertilizedova(a behaviour known asoophagy).[43]In females, only the rightovaryappears to function, and it is currently unknown why only one of the organs seems to function.[44]

Gestationis thought to span over a year (perhaps two to three years), with a small, though unknown, number of young born fully developed at 1.5–2 m (4 ft 11 in – 6 ft 7 in). Only one pregnant female is known to have been caught; she was carrying six unborn young.[45] Mating is thought to occur in early summer, and birthing in late summer, following the female's movement into shallow waters.

The age of maturity is thought to be between the ages of six and 13 and at a length of 4.6–6 m (15–20 ft). Breeding frequency is thought to be two to four years.

The exact lifespan of the basking shark is unknown, but experts estimate it to be about 50 years.[46][47]

Conservation

edit

Aside from direct catches, by-catches in trawl nets have been one of several threats to basking sharks. In New Zealand, basking sharks had been abundant historically; however, after the mass by-catches recorded in the 1990s and 2000s,[48]confirmations of the species became very scarce.[11]Management plans have been declared to promote effective conservation.[49][50]In June 2018 theDepartment of Conservationclassified the basking shark as "Threatened - Nationally Vulnerable" under theNew Zealand Threat Classification System.[51]

The eastern north Pacific Ocean population is a U.S.National Marine Fisheries Servicespecies of concern,one of those species about which the U.S. Government'sNational Oceanic and Atmospheric Administrationhas some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S.Endangered Species Act(ESA).[52]

TheIUCN Red Listindicates this as anendangered species.[2]

The endangered aspect of this shark was publicized in 2005 with apostage stampissued byGuernsey Post.

Importance to humans

edit
The "wonderful fish" described inHarper's Weeklyon 24 October 1868, was likely the remains of a basking shark.

Historically, the basking shark has been a staple of fisheries because of its slow swimming speed, placid nature, and previously abundant numbers. Commercially, it was put to many uses: the flesh for food and fishmeal, the hide forleather,and its largeliver(which has a highsqualenecontent) foroil.[14]It is currently fished mainly for its fins (forshark fin soup). Parts (such ascartilage) are also used intraditional Chinese medicineand as anaphrodisiacin Japan, further adding to demand.

As a result of rapidly declining numbers, the basking shark has been protected in some territorial waters and trade in its products is restricted in many countries underCITES.Among others, it is fully protected in the United Kingdom and the Atlantic and Mexican Gulf regions of the United States.[45]Since 2008, it has been illegal to fish for, or retain if accidentally caught, basking sharks in waters of the European Union.[45]It is partially protected in Norway and New Zealand, as targetedcommercial fishingis illegal, but accidental bycatch can be used (in Norway, any basking shark caught as bycatch and still alive must be released).[2][45][53]As of March 2010, it was also listed under Annex I of theCMSMigratory Sharks Memorandum of Understanding.[54]

Once considered a nuisance along theCanadian Pacific coast,basking sharks were the target of a government eradication programme from 1945 to 1970. As of 2008,efforts were underway to determine whether any sharks still lived in the area and monitor their potential recovery.[55]

It is tolerant of boats and divers approaching it and may even circle divers, making it an important draw for dive tourism in areas where it is common.[56]

Carcass misidentification

edit

On several occasions, "globster"corpses initially identified by non-scientists as asea serpentsorplesiosaurshave later been identified as likely to be the decomposing carcasses of basking sharks, as in theStronsay Beastand theZuiyo-marucases.[57]

See also

edit

References

edit
  1. ^Sepkoski, Jack (2002)."A compendium of fossil marine animal genera (Chondrichthyes entry)".Bulletins of American Paleontology.364:560. Archived fromthe originalon 10 May 2012.Retrieved9 January2008.
  2. ^abcRigby, C.L.; Barreto, R.; Carlson, J.; Fernando, D.; Fordham, S.; Francis, M.P.; Herman, K.; Jabado, R.W.; Liu, K.M.; Marshall, A.; Romanov, E.; Kyne, P.M. (2021) [amended version of 2019 assessment]."Cetorhinus maximus".IUCN Red List of Threatened Species.2021:e.T4292A194720078.doi:10.2305/IUCN.UK.2021-1.RLTS.T4292A194720078.en.
  3. ^"Appendices | CITES".cites.org.Retrieved14 January2022.
  4. ^ab"Basking Shark".
  5. ^Yarrell, William. (1836).A History of British Fishes.Volume II.John Van Voorst, London.p. 397.
  6. ^Kruska, DC (1988). "Brain of the basking shark (Cetorhinus maximus) ".Brain Behav. Evol.32(6): 353–63.doi:10.1159/000116562.PMID3228691.
  7. ^abcSims, DW; Southall, EJ; Richardson, AJ; Reid, PC; Metcalfe, JD (2003)."Seasonal movements and behaviour of basking sharks from archival tagging: no evidence of winter hibernation"(PDF).Marine Ecology Progress Series.248:187–196.Bibcode:2003MEPS..248..187S.doi:10.3354/meps248187.
  8. ^Sims, DW (2008)."Sieving a living: A review of the biology, ecology and conservation status of the plankton-feeding basking sharkCetorhinus maximus".Advances in Marine Biology.54:171–220.doi:10.1016/S0065-2881(08)00003-5.ISBN978-0-12-374351-0.PMID18929065.
  9. ^abC. Knickle; L. Billingsley & K. DiVittorio."Biological Profiles basking shark".Florida Museum of Natural History.Archivedfrom the original on 21 August 2006.Retrieved24 August2006.
  10. ^Welton, Bruce J. (August 2013)."Cetorhinus cf. C. maximus (Gunnerus) (Lamniformes: Cetorhinidae), A Basking Shark from the Late Miocene Empire Formation, Coos Bay, Oregon".Bulletin, Southern California Academy of Sciences.112(2): 74–92.doi:10.3160/0038-3872-112.2.74.ISSN0038-3872.S2CID54927140.
  11. ^abBasking shark.Department of Conservation. govt.nz
  12. ^abSkomal, Gregory B.; Zeeman, Stephen I.; Chisholm, John H.; Summers, Erin L.; Walsh, Harvey J.; McMahon, Kelton W.; Thorrold, Simon R. (2009)."Transequatorial Migrations by Basking Sharks in the Western Atlantic Ocean".Current Biology.19(12): 1019–1022.doi:10.1016/j.cub.2009.04.019.PMID19427211.S2CID15079141.
  13. ^Sims, DW; Southall, EJ; Tarling, GA; Metcalfe, JD (2005)."Habitat-specific normal and reverse diel vertical migration in the plankton-feeding basking shark".Journal of Animal Ecology.74(4): 755–761.doi:10.1111/j.1365-2656.2005.00971.x.
  14. ^abcdCompagno, Leonard J. V. (1984)."CETORHINIDAE – Basking sharks"(PDF).Sharks of the World: An annotated and illustrated catalogue of shark species known to date.Food and Agriculture Organization of the United Nations.
  15. ^abcdeWood, Gerald (1983).The Guinness Book of Animal Facts and Feats.Guinness Superlatives. p.256.ISBN978-0-85112-235-9.
  16. ^Hernández, Sebastián; Vögler, Rodolfo; Bustamante, Carlos; Lamilla, Julio (2010)."Review of the occurrence and distribution of the basking shark ( Cetorhinus maximus) in Chilean waters".Marine Biodiversity Records.3:e67.doi:10.1017/S1755267210000540.ISSN1755-2672.
  17. ^Schwartz, F. J. (2010). "Basking and whale sharks of North Carolina".Journal of the North Carolina Academy of Science.126:84–87.
  18. ^Matthews, L. Harrison; Parker, H. W. (1950)."Notes on the anatomy and biology of the Basking Shark (Cetorhinus maximus (Gunner))".Proceedings of the Zoological Society of London.120(3): 535–576.doi:10.1111/j.1096-3642.1950.tb00663.x.ISSN1469-7998.
  19. ^abCastro, José I. (2011).The sharks of North America.Oxford University Press.ISBN978-0-19-539294-4.OCLC777927872.
  20. ^Collett, Robert (1905).Meddelelser om Norges Fiske i Aarene 1884–1901 (3die Hoved-Supplement til "Norges Fiske", III Slutning).Forhandlinger i Videnskabs–selskabet i Christiania.
  21. ^Coles, R.J. (1915). "Notes on the sharks and rays of Cape Lookout, N. C".Proceedings of the Biological Society of Washington.28:89–94.
  22. ^McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, Dove ADM, Gaskins LC, Helm RR, Hochberg FG, Lee FB, Marshall A, McMurray SE, Schanche C, Stone SN, Thaler AD. 2015. Sizing ocean giants: patterns of intraspecific size variation in marine megafauna.PeerJ3:e715https://doi.org/10.7717/peerj.715
  23. ^"Sharks in the Bay of Fundy, New Brunswick".Retrieved17 October2014.
  24. ^Pauly, D. (2002).Growth and Mortality of the Basking Shark Cetorhinus maximus and their Implications for Management of Whale Sharks Rhincodon typus.Vol. Elasmobranch biodiversity, conservation, and management: proceedings of the international seminar and workshop, Sabah, Malaysia, July 1997. Fowler, Sarah L., Reed, Tim M., Dipper, Frances, 1951-, IUCN--The World Conservation Union. Species Survival Commission. Gland, Switzerland: IUCN.ISBN2-8317-0650-5.OCLC50526779.
  25. ^"Basking Shark".San Francisco State University.Retrieved17 October2014.
  26. ^"Basking shark".redorbit. 19 March 2007.Retrieved17 October2014.
  27. ^Shepard, ELC; Ahmed, MZ; Southall, EJ; Witt, MJ; Metcalfe, JD; Sims, DW (2006)."Diel and tidal rhythms in diving behaviour of pelagic sharks identified by signal processing of archival tagging data".Marine Ecology Progress Series.328:205–213.Bibcode:2006MEPS..328..205S.doi:10.3354/meps328205.
  28. ^Sims, DW (2000). "Filter-feeding and cruising swimming speeds of basking sharks compared with optimal models: they filter-feed slower than predicted for their size".Journal of Experimental Marine Biology and Ecology.249(1): 65–76.doi:10.1016/s0022-0981(00)00183-0.PMID10817828.
  29. ^Pelagic Shark Research Foundation."PSRF Shark Image Library".PSRF.Retrieved1 June2006.
  30. ^Sims, DW; Quayle, VA (1998). "Selective foraging behaviour of basking sharks on zooplankton in a small-scale front".Nature.393(6684): 460–464.Bibcode:1998Natur.393..460S.doi:10.1038/30959.S2CID205000936.
  31. ^abSims, DW (1999)."Threshold foraging behaviour of basking sharks on zooplankton: life on an energetic knife-edge?".Proceedings of the Royal Society B.266(1427): 1437–1443.doi:10.1098/rspb.1999.0798.PMC1690094.
  32. ^"Giant Shark Mystery Solved: Unexpected Hideout Found".News.nationalgeographic. 28 October 2010. Archived fromthe originalon 10 May 2009.Retrieved15 August2012.
  33. ^Howard, Brian Clark (23 June 2015)."Rare, Huge Basking Shark Caught Off Australia".National Geographic.Archived fromthe originalon 24 June 2015.
  34. ^"Rare, giant basking shark caught off Australian coast".CNN.23 June 2015.
  35. ^"Rare 3500kg basking shark caught is donated to science".The Australian.23 June 2015.
  36. ^Osborne, Hannah (23 June 2015)."Australia: Rare 6.3m Basking shark donated to science instead of being sold for its fins".International Business Times.
  37. ^Mancusi, C.; Clò, S.; Affronte, M.; Bradaï, M.N.; Hemida, F.; Serena, F.; Soldo, A.; Vacchi, M. (2005)."On the presence of basking shark (Cetorhinus maximus) in the Mediterranean Sea".Cybium.29(4): 399–405.
  38. ^Cuma. 2009.Çanakkale’de 10 metrelik köpekbalığı!Archived4 September 2017 at theWayback Machine.Retrieved on 4 September 2017
  39. ^Sims, DW; Southall, EJ; Quayle, VA; Fox, AM (2000)."Annual social behaviour of basking sharks associated with coastal front areas".Proceedings of the Royal Society B.267(1455): 1897–1904.doi:10.1098/rspb.2000.1227.PMC1690754.PMID11052542.
  40. ^Sims, DW; Merrett, DA (1997)."Determination of zooplankton characteristics in the presence of surface feeding basking sharksCetorhinus maximus"(PDF).Marine Ecology Progress Series.158:297–302.Bibcode:1997MEPS..158..297S.doi:10.3354/meps158297.
  41. ^"Cetorhinus maximus (Basking shark)".Animal Diversity Web.
  42. ^"Swarms of Huge Sharks Discovered, Baffling Experts".12 April 2018.[dead link‍]
  43. ^"Martin, R. Aidan."Biology of the Basking Shark(Cetorhinus maximus)".ReefQuest Centre for Shark Research.Archivedfrom the original on 28 May 2008.Retrieved8 June2008.
  44. ^"Basking Shark Facts: Habitat, Diet, Conservation & More".9 February 2021.Retrieved22 September2022.
  45. ^abcd"Basking Shark Factsheet".The Shark Trust. Archived fromthe originalon 17 February 2013.Retrieved7 July2006.
  46. ^Archipelagos Wildlife Library."Basking Shark ( Cetorhinus maximus )".Archipelagos Wildlife Library. Archived fromthe originalon 22 January 2013.Retrieved30 April2013.
  47. ^Born Free Foundation."Basking Shark Facts".Born Free Foundation. Archived fromthe originalon 19 February 2013.Retrieved30 April2013.
  48. ^Francis, M. P. & Smith, M. H. (2010)."Basking shark (Cetorhinus maximus) bycatch in New Zealand fisheries, 1994–95 to 2007–08 ".New Zealand Aquatic Environment and Biodiversity Report No. 49.
  49. ^MacFarlane, Trudy (18 June 2010)Submission on Management Options for Basking SharksArchived23 January 2016 at theWayback Machine.Ministry of Fisheries (New Zealand)
  50. ^Management Options for Basking Sharks to Give Effect to New Zealand's International Obligations.Ministry of Fisheries (New Zealand)
  51. ^Duffy, Clinton A. J.; Francis, Malcolm; Dunn, M. R.; Finucci, Brit; Ford, Richard; Hitchmough, Rod; Rolfe, Jeremy (2018).Conservation status of New Zealand chondrichthyans (chimeras, sharks and rays), 2016(PDF).Wellington, New Zealand: Department of Conservation. p. 9.ISBN978-1-988514-62-8.OCLC1042901090.
  52. ^"Proactive Conservation Program: Species of Concern".noaa.gov.5 May 2017.
  53. ^"Fishing (Reporting) Regulations 2001, Schedule 3, Part 2C Protected Fish Species".NZ Government.
  54. ^"MEMORANDUM OF UNDERSTANDING ON THE CONSERVATION OF MIGRATORY SHARKS"(PDF).cms.int.
  55. ^Colonist, Times (21 August 2008)."B.C. scientists hunt for elusive shark".Canada. Archived fromthe originalon 5 November 2012.Retrieved15 August2012.
  56. ^"Cetorhinus maximus".Florida Museum.
  57. ^Kuban, Glen (May 1997)."Sea-monster or Shark?: An Analysis of a Supposed Plesiosaur Carcass Netted in 1977".Reports of the National Center for Science Education.17(3): 16–28.
General references
edit
Wikimedia Commons has media related toCetorhinus maximus.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Basking_shark&oldid=1251231436"