Whale shark
284899
224303652
2008-07-08T06:55:00Z
Da monster under your bed
2040962
Reverted edits by [[Special:Contributions/71.53.10.137|71.53.10.137]] ([[User talk:71.53.10.137|talk]]) to last version by Da monster under your bed
{{Taxobox
| name = Whale shark
| status = VU
| trend = down
| status_system = iucn2.3
| status_ref =<ref name="iucn">{{IUCN2006|assessors=Norman, Brad|year=2000|id=19488|title=Rhincodon typus|downloaded=11 May 2006}} Database entry includes justification for why this [[species]] is vulnerable.</ref>
| image = Whale shark Georgia aquarium.jpg
| image_width = 250px
| image_caption = Whale shark from Taiwan in the [[Georgia Aquarium]]
| image2 = Rhtyp u0 white bg.gif
| image2_width = 250px
| image2_caption = Size comparison against an average human
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Chondrichthyes]]
| subclassis = [[Elasmobranchii]]
| ordo = [[Orectolobiformes]]
| familia = '''Rhincodontidae'''
| familia_authority = ([[Johannes Peter Müller|Müller]] and [[Friedrich Gustav Jakob Henle|Henle]], 1839)
| genus = '''''Rhincodon'''''
| genus_authority = [[Andrew Smith (zoologist)|Smith]], 1829
| species = '''''R. typus'''''
| binomial = ''Rhincodon typus''
| binomial_authority = ([[Andrew Smith (zoologist)|Smith]], 1828)
| range_map = Rhincodon typus distmap.png
| range_map_width = 250px
| range_map_caption = Range of whale shark
}}
The '''whale shark''', ''Rhincodon typus'', is a slow [[filter feeder|filter feeding]] [[shark]] that is the largest living [[fish]] [[species]]. This distinctively-marked shark is the only member of its [[genus]] '''''Rhincodon''''' and its [[family]], '''Rhincodontidae''' (called Rhinodontes before 1984), which is grouped into the subclass [[Elasmobranchii]] in the class [[Chondrichthyes]]. The shark is found in [[tropical]] and warm oceans and lives in the open sea. The species is believed to have originated about 60 million years ago.<ref name=JurassicShark>''Jurassic Shark'' (2000) documentary by Jacinth O'Donnell; broadcast on [[Discovery Channel]], August 5, 2006</ref>
==Naming==
The species was first identified in April 1828 following the harpooning of a {{Convert|4.6|m|ft|1|lk=on|sing=on}} specimen in [[Table Bay]], [[South Africa]]. It was described the following year by [[Andrew Smith (zoologist)|Andrew Smith]], a military doctor associated with British troops stationed in [[Cape Town]]. He proceeded to publish a more detailed description of the species in 1849. The name "whale shark" comes from the fish's physiology; that is, a shark as large as a [[whale]] that shares a similar filter feeder eating mode. Known as a deity in a Vietnamese religion, the whale shark is called "Ca Ong", which literally translates as "Sir Fish"
==Distribution and habitat==
The whale shark inhabits the world's tropical and warm-temperate oceans. While thought to be primarily [[pelagic]], seasonal feeding aggregations of the sharks occur at several coastal sites such as [[Ningaloo Reef]] in [[Western Australia]]; [[Útila]] in [[Honduras]]; [[Donsol]] and [[Batangas]] in the [[Philippines]]; off [[Isla Mujeres]] and [[Holbox|Isla Holbox]] in [[Yucatan]] [[Mexico]]; and the [[Tanzania]]n islands of [[Pemba, Tanzania|Pemba]] and [[Zanzibar]]. Though it is often seen offshore, it has also been found closer to shore, entering lagoons or coral atolls, and near the mouths of estuaries and rivers. Its range is restricted to about ±30 ° latitude. It is found to a depth of {{Convert|700|m|ft|-2}}<ref name="fishbase">{{cite web|author=Ed. Ranier Froese and Daniel Pauly|title=Rhincodon typus|publisher=FishBase|accessdaymonth=17 September |accessyear=2006|url=http://www.fishbase.org/Summary/SpeciesSummary.php?id=2081}}</ref>. The whale shark is solitary and rarely seen in groups unless feeding at locations with an abundance of food. Males range over longer distances than females (which appear to favor specific locations).
==Anatomy and appearance==
As a [[filter feeding|filter feeder]], it has a capacious mouth which can be up to {{Convert|1.5|m|ft|1}} wide and can contain between 300 and 350 rows of tiny teeth.<ref name="FAO">{{cite web|author=Compagno, L.J.V.|title=Species Fact Sheet, Rhincodon typus|publisher=Food and Agriculture Organization of the United Nations|accessdaymonth=19 September |accessyear=2006|url=http://www.fao.org/figis/servlet/species?qid=sp_31005_F2801&ste=st_extra,705263&st_extra=}}</ref> It has five large pairs of [[gill]]s. Two small eyes are located towards the front of the shark's wide, flat head. The body is mostly grey with a white belly; three prominent ridges run along each side of the animal and the skin is marked with a "checkerboard" of pale yellow spots and stripes. These spots are unique to each whale shark and because of this they can be used to identify each animal and hence make an accurate population count. Its skin can be up to {{Convert|10|cm|in|1|lk=on}} thick. The shark has a pair each of [[dorsal fin]]s and [[pectoral fin]]s. A juvenile whale shark's tail has a larger upper fin than lower fin while the adult tail becomes semi-lunate (or crescent-shaped). The whale shark's [[spiracle]]s are just behind the eyes.
[[Image:Whale Shark at Osaka Aquarium.jpg|thumb|Whale shark in main tank at [[Osaka Aquarium Kaiyukan|Osaka Aquarium]].]]
The whale shark is not an efficient swimmer since the entire body is used for swimming, which is unusual for fish and contributes to an average speed of only around {{Convert|5|km/h|mi/h|1|lk=on|sing=on}}. The largest specimen regarded as accurately recorded was caught on [[November 11]], [[1947]], near the island of Baba, not far from [[Karachi]], [[Pakistan]]. It was {{Convert|12.65|m|ft|2}} long, weighed more than 21.5 [[tonne]]s (47,300 [[pound (unit of weight)|lb]]), and had a girth of {{Convert|7|m|ft|1}}.<ref>Gerald L. Wood, ''Animal Facts and Feats'', 1990.</ref> Stories exist of vastly larger specimens — quoted lengths of {{Convert|18|m|ft|0}} are not uncommon in the popular shark literature — but no scientific records exist to support their existence. In 1868 the Irish natural scientist [[Edward Perceval Wright]] spent time in the [[Seychelles]], during which he managed to obtain several small whale shark specimens, but claimed to have observed specimens in excess of {{Convert|15|m|ft|1}}, and tells of reports of specimens surpassing {{Convert|21|m|ft|1}}.
In a 1925 publication, [[Hugh McCormick Smith|Hugh M. Smith]] describes a huge whale shark caught in a bamboo fish trap in [[Thailand]] in 1919. The shark was too heavy to pull ashore, but Smith estimated that the shark was at least {{Convert|17|m|ft|0}} long, and weighed approximately 37 tonnes (81,500 lb), which have been exaggerated to a more precise measurement of {{Convert|17.98|m|ft|2}} and weight 43 tonnes in recent years. A shark caught in 1994 near [[Tainan]] county in Southern [[Taiwan]] is reported to have weighed 35.8 tonnes (78,887 lb).<ref>http://homepage.mac.com/mollet/Rt/Rt_large.html</ref> There have even been claims of whale sharks of up to {{Convert|23|m|ft|0}}. In 1934 a ship named the ''Maurguani'' came across a whale shark in the Southern Pacific Ocean, rammed it, and the shark consequently became stuck on the prow of the ship, supposedly with {{Convert|4.6|m|ft|1}} on one side and {{Convert|12.2|m|ft|1}} on the other.<ref>Xavier Maniguet, ''Jaws of Death''; 1991.</ref> No reliable documentation exists of those claims and they remain little more than "fish-stories".
==Diet==
[[Image:Rhincodon typus.jpg|thumb|right|200px|A whale shark in the [[Maldives]]]]
The whale shark is a filter feeder — one of only three known filter feeding shark species (along with the [[basking shark]] and the [[megamouth shark]]). It feeds on [[phytoplankton]], macro-[[algae]], [[plankton]], [[krill]] and small [[nekton]]ic life, such as small [[squid]] or [[vertebrate]]s. The many rows of teeth play no role in feeding; in fact, they are reduced in size in the whale shark. Instead, the shark sucks in a mouthful of water, closes its mouth and expels the water through its gills. During the slight delay between closing the mouth and opening the gill flaps, plankton is trapped against the [[dermal denticle]]s which line its gill plates and [[pharynx]]. This fine sieve-like apparatus, which is a unique modification of the gill rakers, prevents the passage of anything but fluid out through the gills (anything above 2 to 3 mm in diameter is trapped). Any material caught in the filter between the gill bars is swallowed. Whale sharks have been observed "coughing" and it is presumed that this is a method of clearing a build up of food particles in the gill rakers.<ref name="fishbase"/><ref name="RQBM">{{cite web|author=Martin, R. Aidan.|title=Elasmo Research|publisher=ReefQuest|accessdaymonth=17 September |accessyear=2006|url=http://www.elasmo-research.org/education/topics/d_filter_feeding.htm}}</ref><ref name="FLMNH">{{ cite web|url=http://www.flmnh.ufl.edu/fish/Gallery/Descript/Whaleshark/whaleshark.html|title= Whale shark|publisher = Icthyology at the Florida Museum of Natural History|accessdate=17 September|accessyear=2006}}</ref>
Whale sharks congregate at reefs off the [[Belize]]an [[Caribbean]] coast, supplementing their ordinary diet by feeding on the [[roe]] of giant cubera snappers, which spawn in these waters between the full and quarter moons of May, June, and July.
The whale shark is an active feeder and targets concentrations of plankton or fish by [[olfactory]] cues. Rather than simply "vacuuming" constantly, it is able to pump water over its gills. The shark can circulate water at a rate up to 1.7 L/s (3.5 U.S. pint/s).{{Fact|date=March 2007}} The whale shark does not need to swim forward when feeding; it is often observed in a vertical position, "bobbing" up and down swallowing water and actively filtering it for food. This is in contrast to the [[basking shark]], which is a passive feeder and does not pump water; it relies on its swimming to force water over its gills.<ref name="RQBM" /><ref name="fishbase" />
==Behavior towards divers==
[[Image:Whale shark austalia.jpg|thumb|A whale shark at [[Ningaloo Reef]]]]
This species, despite its enormous size, does not pose any significant danger to humans. It is a frequently cited example when educating the public about the popular misconceptions of all sharks as "man-eaters". They are actually quite gentle and can be playful with divers. There are unconfirmed reports of sharks lying still, upside down on the surface to allow divers to scrape parasites and other organisms from their bellies. Divers and snorkelers can swim with this giant fish without any risk apart from unintentionally being struck by the shark's large tail fin.
The shark is often seen by divers in [[Útila|The Bay Islands in Honduras]], [[Thailand]], the [[Philippines]], the [[Maldives]], the [[Red Sea]], [[Western Australia]] ([[Ningaloo Reef]] and [[Christmas Island]]), Gladden Spit Marine Reserve in [[Belize]], Tofo Beach in [[Mozambique]], Sodwana Bay ([[Greater St. Lucia Wetland Park]]) in South Africa and at the [[Galapagos]] Islands.
The highest concentration of whale sharks to be found anywhere in the world is in the [[Philippines]]. From January to May, they congregate in the shallow coastal waters of [[Sorsogon]] province (at [[Donsol]]). Lucky divers have also come across whale sharks in the [[Seychelles]] and in [[Puerto Rico]]. Between December and September, they are well known to swim along the bay of La Paz in Mexico's [[Baja California]]. Sometimes, they are accompanied by smaller fish, in particular, the [[remora]]. Recently, they have been seen in the vicinity of [[Tenggol Island]], off the east coast of [[West Malaysia]].{{Fact|date=October 2007}}They are also frequently spotted around other Coral Reefs along the West Malaysian coast including [[Kapas Island]] and [[Redang Island]].
==Reproduction==
The [[reproductive]] habits of the whale shark are obscure. Based on the study of a single egg recovered off the coast of [[Mexico]] in 1956, it was believed to be [[oviparous]], but the capture of a female in July 1996 which was pregnant with 300 pups indicates that they are [[Ovoviviparity|ovoviviparous]].<ref>Shoou-Jeng Joung1, Che-Tsung Chen, Eugenie Clark, Senzo Uchida and William Y. P. Huang. The whale shark, ''Rhincodon typus'', is a livebearer: 300 [[embryo]]s found in one ‘megamamma’ supreme. Environmental Biology of Fishes Volume 46, Number 3 / July, 1996</ref><ref name="fishbase" /><ref name="sharklady">{{cite web|author=Dr. [[Eugenie Clark]]|title=Frequently Asked Questions|accessdaymonth=26 September |accessyear=2006|url=http://www.sharklady.com/faq.html#A12}}</ref> The eggs remain in the body and the females give birth to live young which are {{Convert|40|cm|in|1}} to {{Convert|60|cm|in|1}} long. It is believed that they reach sexual maturity at around 30 years and the life span has been estimated to be over 100 years.<ref>{{Citation|contribution=Whale Shark (Rhincodon typus) Issues Paper|title=Biology of Whale Shark|year=2005|publisher=Department of the Environment and Heritage (Australian Government)|url=http://www.environment.gov.au/biodiversity/threatened/publications/recovery/r-typus-issues/biology.html}}</ref>
==Conservation status==
The whale shark is targeted by [[artisan fishing|artisanal]] and [[Fishing industry|commercial fisheries]] in several areas where they seasonally aggregate. The population is unknown and the species is considered [[vulnerable species|vulnerable]] by the [[International Union for Conservation of Nature and Natural Resources|IUCN]].<ref name="iucn"/> All fishing, selling, importing and exporting of whale sharks for commercial purposes has been banned in the [[Philippines]] since 1998,<ref>[http://www.flmnh.ufl.edu/fish/Sharks/InNews/Whaleshark.htm ''Whale Sharks Receive Protection in the Philippines'']</ref> India in May 2001,<ref> [http://www.environment.gov.au/biodiversity/threatened/publications/recovery/r-typus-issues/legal-status.html ''National Regulations on Whale Shark fishing'']</ref> followed by Taiwan in May 2007.<ref>[http://www.taipeitimes.com/News/taiwan/archives/2007/05/27/2003362648 ''COA bans fishing for whale sharks'']</ref>
==Whale sharks in captivity==
[[Image:Male whale shark at Georgia Aquarium.jpg|thumb|right|220px|A whale shark in the [[Georgia Aquarium]]]]
A whale shark is featured as the main attraction of [[Osaka Aquarium Kaiyukan]] and as of 2005, three whale sharks are being studied in [[captivity]] at the [[Okinawa Churaumi Aquarium]] in [[Japan]]. Four whale sharks, two males, Taroko, and Yushan,<ref>{{citeweb | url=http://www.cnn.com/2007/TECH/science/06/01/aquarium.whale.sharks.ap/index.html |title= Aquarium gains two new whale sharks |month=June 1 |year=2007 |publisher=CNN.com |accessmonthday=June 1 |accessyear=2007}}</ref> and two females, Alice and Trixie, are held in the [[Georgia Aquarium]], in [[Atlanta]]. Two male whale sharks, Ralph and Norton, died in captivity at the Georgia Aquarium on January 11, 2007 and June 13, 2007 respectively.<ref>{{citeweb |url=http://news.yahoo.com/s/ap/20070613/ap_on_re_us/whale_shark_dies_1;_ylt=AnVHZffZC60_oQt3rO_bITUE1vAI |title=2nd whale shark dies at Ga. Aquarium |month=June 13 |year=2007 |publisher=Yahoo.com |accessmonthday=June 13 |accessyear=2007}}</ref> The two males were added on [[June 3]], [[2006]] in hopes that reproduction in whale sharks could be studied in captivity. All six whale sharks were imported from [[Taiwan]], where whale sharks are dubbed [[tofu]] sharks because of the taste and texture of the flesh.
==See also==
{{Sharksportal}}
* [[List of sharks]]
==References==
{{reflist|2}}
;General references
{{refbegin}}
* J. G. Colman (1997). A review of the biology and ecology of the whale shark. Journal of Fish Biology 51 (6), 1219–1234.
* [http://www.fao.org/figis/servlet/species?qid=sp_31005_F2801&ste=st_extra,705263&st_extra= FAO web page on Whale shark]
* {{FishBase_species|genus=Rhincodon|species=typus|year=2004|month=November}}
* {{ITIS|ID=159857|taxon=Rhincodon typus|year=2005|date=16 November}}
{{refend}}
==External links==
{{Commons|Category:Rhincodon typus|Whale shark}}
* [http://www.whaleshark.org/submit.jsp Reporting a whale shark sighting]
* [http://www.whaleshark.org/photographing.jsp How to photograph a whale shark for mark-recapture research]
* [http://forum.ecocean.org/ Whale Shark Research Discussion Forum]
* [http://www.sharkgrid.org/ sharkGrid - a grid computer for whale shark research]
* [http://www.utilawhalesharkresearch.com/ Whale Shark Research in Utila, Honduras]
* [http://www.youtube.com/whalesharkfilm / A short film about Utilas Whale Sharks]
* [http://mozmarinescience.googlepages.com/ Whale Shark research in Mozambique]
* {{marinebio|id=47|name=Whale shark, Rhincodon typus}}
* [http://www.whaleshark.org ECOCEAN Whale Shark Photo-identification Library]
* [http://www.whalesharkproject.org Whale Shark Project]
* [http://news.bbc.co.uk/1/hi/sci/tech/2251464.stm Whale sharks]
* [http://www.time.com/time/asia/2004/boa/boa_soul_donsoll.html TimeAsia.com: Best of Asia, Best Animal Encounter]
* [http://www.nature.org/magazine/spring2003/features/whaleshark.html Whale Shark profile] and [http://www.nature.org/wherewework/centralamerica/belize/work/art10457.html whale sharks in Belize] from [[The Nature Conservancy]]
* [http://www.dive-the-world.com/creatures-whale-sharks.htm Diving with whale sharks]
* [http://www.belizescuba.com/whalesharks.lasso Diving with whale sharks in Belize at Gladden Split]
* [http://wetpixel.com/i.php/full/albino-whale-shark-photographed-in-ecuador Albino whale shark photographed in Galapagos]
[[Category:Ovoviviparous fish]]
[[Category:Rhincodontidae]]
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