Whale shark
Encyclopedia
The whale shark, Rhincodon typus, is a slow-moving filter feeding
shark
, the largest extant fish
species
. The largest confirmed individual had a length of 12.65 metres (41.5 ft) and a weight of more than 21.5 tonnes (47,399.4 lb), but unconfirmed claims report considerably larger whale sharks. This distinctively-marked fish is the only member of its genus
Rhincodon and its family
, Rhincodontidae (called Rhinodontes before 1984), which belongs to the subclass Elasmobranchii
in the class Chondrichthyes
. This shark, found in tropical and warm oceans, lives in the open sea with a lifespan of about 70 years. The species originated about 60 million years ago. Although whale sharks have very large mouths, they feed mainly, though not exclusively, on plankton
, microscopic plants and animals. However, the BBC program Planet Earth
filmed a whale shark feeding on a school of small fish. The same documentary showed footage of a whale shark timing its arrival to coincide with the mass spawning of fish shoals and feeding on the resultant clouds of eggs and sperm.
The species was distinguished in April 1828, following the harpooning of a 4.6 metres (15.1 ft) specimen in Table Bay
, South Africa
. Andrew Smith
, a military doctor associated with British troops stationed in Cape Town
described it the following year. He published a more detailed description in 1849. The name "whale shark" comes from the fish's physiology; as large as a whale
, it too is a filter feeder.
; Gladden Spit in Belize
; Ningaloo Reef
in Western Australia
; Great Rann of Kutch in India
; Útila
in Honduras
; Donsol, Pasacao and Batangas
in the Philippines
; off Isla Mujeres
and Isla Holbox in Yucatan
, Mexico
; Ujung Kulon National Park
in Indonesia
; Nosy Be
in Madagascar
Off Tofo
Reef near Inhambane
in Mozambique
, and the Tanzania
n islands of Mafia
, Pemba
, Zanzibar
and, very rarely, Eilat, Israel
. Although typically seen offshore, it has been found closer to land, entering lagoons or coral atolls, and near the mouths of estuaries and rivers. Its range is generally restricted to about ±30° latitude. It is capable of diving to depths of 700 metres (2,296.6 ft), and is migratory.
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 individual and are useful for counting populations. Its skin can be up to 10 centimetres (3.9 in) thick. The shark has a pair each of dorsal fin
s and pectoral fins. Juveniles' tails have a larger upper than lower fin while the adult tail becomes semi-lunate
(crescent-shaped). Spiracle
s are just behind the eyes.
The whale shark is not an efficient swimmer since it uses its entire body, unusual for fish, to attain an average speed of around 5 kilometre per hour. The whale shark is largest animal in the world outside of the large cetaceans. The average size of adult whale sharks is estimated at 9.7 metres (31.82 ft) and 9 tonnes (19,841.6 lb). The largest verified specimen was caught on November 11, 1947, near Baba Island, in Karachi
, Pakistan
. It was 12.65 metres (41.5 ft) long, weighed more than 21.5 tonnes (47,399.4 lb), and had a girth of 7 metres (23 ft). Stories exist of vastly larger specimens — quoted lengths of 18 metres (59 ft) are not uncommon in the popular shark literature — but no scientific records support their existence. In 1868 the Irish natural scientist Edward Perceval Wright
obtained several small whale shark specimens in the Seychelles
, but claimed to have observed specimens in excess of 15 metres (49.2 ft), and tells of reports of specimens surpassing 21 metres (68.9 ft).
In a 1925 publication, Hugh M. Smith
described a huge animal 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 17 metres (56 ft) long, and weighed approximately 37 tonnes (81,571 lb). These measurements have been exaggerated to 43 tonnes (94,798.8 lb) and a more precise 17.98 metres (58.99 ft) in recent years. A shark caught in 1994 off Tainan County
, southern Taiwan
reportedly weighed 35.8 tonnes (78,925.5 lb). There have even been claims of whale sharks of up to 23 metres (75 ft). 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 4.6 metres (15.1 ft) on one side and 12.2 metres (40 ft) on the other. No reliable documentation exists for these claims and they remain "fish-stories".
and the megamouth shark
). It feeds on macro-algae
, plankton
, krill
, Christmas Island red crab
larvae, and small nekton
ic life such as small squid
or vertebrate
s. It also feeds on small fish and the clouds of eggs and sperm during mass spawning of fish shoals. 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 denticles 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, trapping anything above 2 to 3 mm (0.078740157480315 to 0.118110236220472 ) in diameter. 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. Whale sharks migrate to feed and possibly to breed.
The whale shark is an active feeder, targeting concentrations of plankton or fish. It is able to ram filter feed or can gulp in a stationary position. This is in contrast to the passive feeding basking shark
, which does not pump water. Instead, it swims to force water across its gills.
The shark is seen by divers in many places, including the Bay Islands in Honduras
, Thailand
, the Philippines
, the Maldives
, the Red Sea
, Western Australia
(Ningaloo Reef
, Christmas Island
), Taiwan
, Panama
(Isla Coiba), Belize
, Tofo Beach in Mozambique
, Sodwana Bay (Greater St. Lucia Wetland Park
) in South Africa, the Galapagos Islands, Isla Mujeres
in Mexico
, the Seychelles
, West Malaysia, islands off eastern peninsular Malaysia
, Sri Lanka
, Oman
, Fujairah
, and Puerto Rico
.
Two whale sharks are featured as the main attraction of Osaka Aquarium Kaiyukan
and as of 2005, three whale sharks are in captivity
at the Okinawa Churaumi Aquarium
in Japan
. The Ioworld Aquarium in Kagoshima, Japan
, also features a single adult whale shark as a major attraction. One is also on display in the Taiwan, Kenting
National Museum of Biology
and Aquarium
. Four whale sharks, two males, Taroko, and Yushan, and two females, Alice and Trixie, live in the Georgia Aquarium
, in Atlanta, USA. Two male whale sharks, Ralph and Norton, died in captivity at the Georgia Aquarium on January 11, 2007, and June 13, 2007, respectively. The two females 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. Two whale sharks live at Polar Ocean World in Qingdao, China. One whale shark was at the Atlantis Hotel
in Dubai, but was released in March, 2010.
. The eggs remain in the body and the females give birth to live young which are 40 to 60 cm (15.7 to 23.6 ) long. It is believed that they reach sexual maturity at around 30 years and the life span is an estimated 70 to 100 years.
On March 7, 2009, marine scientists in the Philippines discovered what is believed to be the smallest living specimen of the whale shark. The young shark, measuring only 38 centimetres (15 in), was found with its tail tied to a stake at a beach in Pilar, Philippines, and was released into the wild. Based on this discovery some scientists no longer believe that this area is just a feeding ground; it may also be that this site is a birthing ground as well.
in several areas where they seasonally aggregate. The population is unknown and the species is considered vulnerable
by the IUCN. In 1998, the Philippines
banned all fishing, selling, importing and exporting of whale sharks for commercial purposes, followed by India in May 2001, and Taiwan in May 2007. They are currently listed as a vulnerable species; however, they continue to be hunted in parts of Asia, such as Taiwan and the Philippines.
In 2006, Resorts World Sentosa announced its plans to bring in whale sharks for their marine life park. This was met with opposition from seven notable conservation societies. In 2009, the plan was shelved in favour of a search for other alternatives.
In 2010, the Gulf of Mexico oil spill
resulted in 4900000 barrels (779,037,745.5 l) of oil flowing into an area south of the Mississippi River Delta
, where one-third of all whale shark sightings in the northern part of the gulf have occurred in recent years. Sightings confirmed that the whale sharks were unable to avoid the oil slick which was situated on the surface of the sea where the whale sharks feed for several hours at a time. However, no dead whale sharks have been found.
.
ese culture, the whale shark is called "Ca Ong", which literally translates as "Sir Fish".
In Mexico, and throughout much of Latin America, the whale shark is known as "pez dama" or "domino" for its distinctive patterns of spots. However, they go by "Sapodilla Tom" in Belize due to the regularity of sightings near the Sapodilla Cayes on the Belize Barrier Reef
.
In Africa, the names for the whale shark are very evocative: "papa shillingi" in Kenya came from the myth that God threw shillings upon the shark which are now its spots. In Madagascar the name is "marokintana" meaning "many stars".
Javanese
also reference the stars by calling it "geger lintang," meaning "stars in the back". In the Philippines, it is called "butanding", while in Madurese
, it is known as "kikaki".
Filter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...
shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....
, the largest extant fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
. The largest confirmed individual had a length of 12.65 metres (41.5 ft) and a weight of more than 21.5 tonnes (47,399.4 lb), but unconfirmed claims report considerably larger whale sharks. This distinctively-marked fish is the only member of its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Rhincodon and its family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...
, Rhincodontidae (called Rhinodontes before 1984), which belongs to the subclass Elasmobranchii
Elasmobranchii
Elasmobranchii is a subclass of Chondrichthyes or cartilaginous fish, that includes the sharks and the rays and skates .-Evolution:...
in the class Chondrichthyes
Chondrichthyes
Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone...
. This shark, found in tropical and warm oceans, lives in the open sea with a lifespan of about 70 years. The species originated about 60 million years ago. Although whale sharks have very large mouths, they feed mainly, though not exclusively, on plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
, microscopic plants and animals. However, the BBC program Planet Earth
Planet Earth (TV series)
Planet Earth is a 2006 television series produced by the BBC Natural History Unit. Five years in the making, it was the most expensive nature documentary series ever commissioned by the BBC, and also the first to be filmed in high definition...
filmed a whale shark feeding on a school of small fish. The same documentary showed footage of a whale shark timing its arrival to coincide with the mass spawning of fish shoals and feeding on the resultant clouds of eggs and sperm.
The species was distinguished in April 1828, following the harpooning of a 4.6 metres (15.1 ft) specimen in Table Bay
Table Bay
Table Bay is a natural bay on the Atlantic Ocean overlooked by Cape Town and is at the northern end of the Cape Peninsula, which stretches south to the Cape of Good Hope. It was named because it is dominated by the flat-topped Table Mountain.Bartolomeu Dias was the first European to explore this...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. Andrew Smith
Andrew Smith (zoologist)
Sir Andrew Smith KCB was a Scottish surgeon, explorer, ethnologist and zoologist. He is considered the father of Zoology in South Africa having described many species across a wide range of groups in his major work, Illustrations of the Zoology of South Africa.Smith was born in Hawick, Roxburghshire...
, a military doctor associated with British troops stationed in Cape Town
Cape Town
Cape Town is the second-most populous city in South Africa, and the provincial capital and primate city of the Western Cape. As the seat of the National Parliament, it is also the legislative capital of the country. It forms part of the City of Cape Town metropolitan municipality...
described it the following year. He published a more detailed description in 1849. The name "whale shark" comes from the fish's physiology; as large as a whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
, it too is a filter feeder.
Distribution and habitat
The whale shark inhabits all tropical and warm-temperate seas. They are known to migrate every spring to the continental shelf of the central west coast of Australia. The coral spawning of the area's Ningaloo Reef provides the whale shark with an abundant supply of plankton. Primarily pelagic, seasonal feeding aggregations occur at several coastal sites such as the southern and eastern parts of South AfricaSouth Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
; Gladden Spit in Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
; Ningaloo Reef
Ningaloo Reef
Ningaloo Reef is a fringing coral reef located off the west coast of Australia, approximately 1200 km north of Perth. The reef is 260 km long and is Australia's largest fringing coral reef and the only large reef positioned very close to a landmass....
in Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
; Great Rann of Kutch in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
; Útila
Útila
Utila is the third largest of Honduras' Bay Islands, after Roatán and Guanaja, in a region that marks the south end of the Mesoamerican Barrier Reef System, the second-largest in the world...
in Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
; Donsol, Pasacao and Batangas
Batangas
Batangas is a first class province of the Philippines located on the southwestern part of Luzon in the CALABARZON region. Its capital is Batangas City and it is bordered by the provinces of Cavite and Laguna to the north and Quezon to the east. Across the Verde Island Passages to the south is the...
in the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
; off Isla Mujeres
Isla Mujeres
Isla Mujeres is one of the ten municipalities of the Mexican state of Quintana Roo. The municipality, located in the northeastern corner of the state is mostly on the mainland and has a municipal seat of the same name; Isla Mujeres...
and Isla Holbox in Yucatan
Yucatán
Yucatán officially Estado Libre y Soberano de Yucatán is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 106 municipalities and its capital city is Mérida....
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
; Ujung Kulon National Park
Ujung Kulon National Park
Ujung Kulon National Park is located at the western-most tip of Java, Banten, Indonesia. It includes the volcanic island group of Krakatoa and other islands including Panaitan, Handeuleum and Peucang on the Sunda Strait.-Geography:...
in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
; Nosy Be
Nosy Be
Nosy Be is an island located off the northwest coast of Madagascar. Nosy Be is Madagascar's largest and busiest tourist resort. It has an area of 312 km2 and its population was officially estimated at 36,636 in 2001....
in Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
Off Tofo
Tofo
Praia do Tofo or simply Tofo is a small town in southeastern Mozambique. The town lies on the Indian Ocean coast, on Ponto do Barra peninsula in Inhambane Province, 22 km drive from Inhambane city...
Reef near Inhambane
Inhambane
Inhambane, Terra de Boa Gente is a city located in southern Mozambique, lying on Inhambane Bay, 470 km northeast of Maputo. It is the capital of the Inhambane Province and according to the 2008 census has a population of 65,837, growing from the 1997 census of 54,157...
in Mozambique
Mozambique
Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
, and the Tanzania
Tanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
n islands of Mafia
Mafia Island
Mafia Island is part of the Tanzanian Spice Islands, together with Unguja and Pemba. As one of the six districts of the Pwani Region, Mafia Island is governed from the mainland, not from the semi-autonomous region of Zanzibar, of which it has never been considered to be a part.According to the...
, Pemba
Pemba, Tanzania
Pemba Island, known as "The Green Island" in Arabic , is an island forming part of the Zanzibar archipelago, lying off the east coast of Africa in the Indian Ocean. It is situated about 50 kilometres to the north of the Unguja . In 1964 Zanzibar was united with the former colony of Tanganyika to...
, Zanzibar
Zanzibar
Zanzibar ,Persian: زنگبار, from suffix bār: "coast" and Zangi: "bruin" ; is a semi-autonomous part of Tanzania, in East Africa. It comprises the Zanzibar Archipelago in the Indian Ocean, off the coast of the mainland, and consists of numerous small islands and two large ones: Unguja , and Pemba...
and, very rarely, Eilat, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
. Although typically seen offshore, it has been found closer to land, entering lagoons or coral atolls, and near the mouths of estuaries and rivers. Its range is generally restricted to about ±30° latitude. It is capable of diving to depths of 700 metres (2,296.6 ft), and is migratory.
Description
As a filter feeder it has a capacious mouth which can be up to 1.5 metres (4.9 ft) wide and can contain between 300 and 350 rows of tiny teeth. It has five large pairs of gillGill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
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 individual and are useful for counting populations. Its skin can be up to 10 centimetres (3.9 in) thick. The shark has a pair each of dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s and pectoral fins. Juveniles' tails have a larger upper than lower fin while the adult tail becomes semi-lunate
Lunate
Lunate is a term meaning crescent or moon-shaped. In the specialized terminology of lithic reduction, a lunate flake is a small, crescent-shaped flake removed from a stone tool during the process of pressure flaking....
(crescent-shaped). Spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
s are just behind the eyes.
The whale shark is not an efficient swimmer since it uses its entire body, unusual for fish, to attain an average speed of around 5 kilometre per hour. The whale shark is largest animal in the world outside of the large cetaceans. The average size of adult whale sharks is estimated at 9.7 metres (31.82 ft) and 9 tonnes (19,841.6 lb). The largest verified specimen was caught on November 11, 1947, near Baba Island, in Karachi
Karachi
Karachi is the largest city, main seaport and the main financial centre of Pakistan, as well as the capital of the province of Sindh. The city has an estimated population of 13 to 15 million, while the total metropolitan area has a population of over 18 million...
, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...
. It was 12.65 metres (41.5 ft) long, weighed more than 21.5 tonnes (47,399.4 lb), and had a girth of 7 metres (23 ft). Stories exist of vastly larger specimens — quoted lengths of 18 metres (59 ft) are not uncommon in the popular shark literature — but no scientific records support their existence. In 1868 the Irish natural scientist Edward Perceval Wright
Edward Perceval Wright
Edward Percival Wright was an Irish ophthalmic surgeon, botanist and zoologist.-Family, education and career:He was the eldest son of barrister, Edward Wright and Charlott Wright. Edward was educated by a private tutor, and was taught natural history by George James Allman. From 1852 he studied at...
obtained several small whale shark specimens in the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, but claimed to have observed specimens in excess of 15 metres (49.2 ft), and tells of reports of specimens surpassing 21 metres (68.9 ft).
In a 1925 publication, Hugh M. Smith
Hugh McCormick Smith
Hugh McCormick Smith was an American ichthyologist and administrator in the Bureau of Fisheries.-Biography:...
described a huge animal caught in a bamboo fish trap in Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
in 1919. The shark was too heavy to pull ashore, but Smith estimated that the shark was at least 17 metres (56 ft) long, and weighed approximately 37 tonnes (81,571 lb). These measurements have been exaggerated to 43 tonnes (94,798.8 lb) and a more precise 17.98 metres (58.99 ft) in recent years. A shark caught in 1994 off Tainan County
Tainan County
Tainan County was located in southern Taiwan. The name "Tainan" means "Southern Taiwan". Formerly a county of the Republic of China , Tainan County was merged with Tainan City at the end of 2010 to form a single special municipality....
, southern Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
reportedly weighed 35.8 tonnes (78,925.5 lb). There have even been claims of whale sharks of up to 23 metres (75 ft). 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 4.6 metres (15.1 ft) on one side and 12.2 metres (40 ft) on the other. No reliable documentation exists for these claims and they remain "fish-stories".
Diet
The whale shark is a filter feeder — one of only three known filter feeding shark species (along with the basking sharkBasking shark
The basking shark is the second largest living fish, after the whale shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow moving and generally harmless filter feeder and has anatomical adaptations to filter feeding, such as a greatly enlarged...
and the megamouth shark
Megamouth shark
The megamouth shark, Megachasma pelagios, is an extremely rare species of deepwater shark. Since its discovery in 1976, only a few megamouth sharks have been seen, with 53 specimens known to have been caught or sighted as of 2011, including three recordings on film...
). It feeds on macro-algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
, krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
, Christmas Island red crab
Christmas Island red crab
The Christmas Island red crab, Gecarcoidea natalis, is a species of land crab that is endemic to Christmas Island and the Cocos Islands in the Indian Ocean...
larvae, and small nekton
Nekton
Nekton refers to the aggregate of actively swimming aquatic organisms in a body of water able to move independently of water currents....
ic life such as small squid
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
or vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
s. It also feeds on small fish and the clouds of eggs and sperm during mass spawning of fish shoals. 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 denticles which line its gill plates and pharynx
Pharynx
The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...
. 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, trapping anything above 2 to 3 mm (0.078740157480315 to 0.118110236220472 ) in diameter. 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. Whale sharks migrate to feed and possibly to breed.
The whale shark is an active feeder, targeting concentrations of plankton or fish. It is able to ram filter feed or can gulp in a stationary position. This is in contrast to the passive feeding basking shark
Basking shark
The basking shark is the second largest living fish, after the whale shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow moving and generally harmless filter feeder and has anatomical adaptations to filter feeding, such as a greatly enlarged...
, which does not pump water. Instead, it swims to force water across its gills.
Behaviour toward divers
Despite its size, the whale shark does not pose significant danger to humans. Although massive, whale sharks are docile fish and sometimes allow swimmers to catch a ride. Whale sharks are actually quite gentle and can play with divers. Divers and snorkellers can swim with this giant fish without risk, apart from unintentional blows from the shark’s large tail fin. In July 2011, several sources reported, with photos, an incident of a diver who, allegedly, was nearly sucked into the mouth of a whale shark (but escaped unharmed) off the coast of Isla Mujeres, Mexico.The shark is seen by divers in many places, including the Bay Islands in Honduras
Útila
Utila is the third largest of Honduras' Bay Islands, after Roatán and Guanaja, in a region that marks the south end of the Mesoamerican Barrier Reef System, the second-largest in the world...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, the Maldives
Maldives
The Maldives , , officially Republic of Maldives , also referred to as the Maldive Islands, is an island nation in the Indian Ocean formed by a double chain of twenty-six atolls oriented north-south off India's Lakshadweep islands, between Minicoy Island and...
, the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
, Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
(Ningaloo Reef
Ningaloo Reef
Ningaloo Reef is a fringing coral reef located off the west coast of Australia, approximately 1200 km north of Perth. The reef is 260 km long and is Australia's largest fringing coral reef and the only large reef positioned very close to a landmass....
, Christmas Island
Christmas Island
The Territory of Christmas Island is a territory of Australia in the Indian Ocean. It is located northwest of the Western Australian city of Perth, south of the Indonesian capital, Jakarta, and ENE of the Cocos Islands....
), Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
(Isla Coiba), Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
, Tofo Beach in Mozambique
Mozambique
Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
, Sodwana Bay (Greater St. Lucia Wetland Park
Greater St. Lucia Wetland Park
iSimangaliso Wetland Park is situated on the east coast of KwaZulu-Natal, South Africa about 275 kilometres north of Durban. It is South Africa's third-largest protected area, spanning 280 km of coastline, from the Mozambican border in the north to Mapelane south of the St Lucia estuary, and...
) in South Africa, the Galapagos Islands, Isla Mujeres
Isla Mujeres
Isla Mujeres is one of the ten municipalities of the Mexican state of Quintana Roo. The municipality, located in the northeastern corner of the state is mostly on the mainland and has a municipal seat of the same name; Isla Mujeres...
in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, West Malaysia, islands off eastern peninsular Malaysia
Peninsular Malaysia
Peninsular Malaysia , also known as West Malaysia , is the part of Malaysia which lies on the Malay Peninsula. Its area is . It shares a land border with Thailand in the north. To the south is the island of Singapore. Across the Strait of Malacca to the west lies the island of Sumatra...
, Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
, Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
, Fujairah
Fujairah
Fujairah is one of the seven emirates that make up the United Arab Emirates, and the only one on the Gulf of Oman in the country's east instead of Persian Gulf .-History:...
, and Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
.
In captivity
Osaka Aquarium Kaiyukan
The is an aquarium located in the ward of Minato in Osaka, Japan, near Osaka Bay. It is one of the largest public aquariums in the world, and is a member of the Japanese Association of Zoos and Aquariums ....
and as of 2005, three whale sharks are in captivity
Captivity (animal)
Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
at the Okinawa Churaumi Aquarium
Okinawa Churaumi Aquarium
The , located within the Ocean Expo Commemorative National Government Park in Okinawa, Japan. It welcomed its 20 millionth visitor on 30 March 2010 and is a member of the Japanese Association of Zoos and Aquariums .-History:...
in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The Ioworld Aquarium in Kagoshima, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, also features a single adult whale shark as a major attraction. One is also on display in the Taiwan, Kenting
Kenting National Park
Kenting National Park is a national park located in the Hengchun Peninsula of Pingtung County, Taiwan, covering Hengchun, Checheng and Manjhou Townships. Established on January 1, 1984, it is Taiwan's oldest and southernmost national park, covering the southernmost area of the Taiwan island...
National Museum of Biology
and Aquarium
National Museum of Marine Biology and Aquarium
The National Museum of Marine Biology and Aquarium is an aquarium located on the southern coast of Taiwan near Kenting in Checheng, Pingtung County, Taiwan.-Overview:...
. Four whale sharks, two males, Taroko, and Yushan, and two females, Alice and Trixie, live in the Georgia Aquarium
Georgia Aquarium
The Georgia Aquarium, located in Atlanta, Georgia, United States, at Pemberton Place, is the world's largest aquarium with more than of marine and fresh water housing more than 120,000 animals of 500 different species...
, in Atlanta, USA. Two male whale sharks, Ralph and Norton, died in captivity at the Georgia Aquarium on January 11, 2007, and June 13, 2007, respectively. The two females 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
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, where whale sharks are dubbed tofu
Tofu
is a food made by coagulating soy milk and then pressing the resulting curds into soft white blocks. It is part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese, and others. There are many different varieties of tofu, including fresh tofu and tofu...
sharks because of the taste and texture of the flesh. Two whale sharks live at Polar Ocean World in Qingdao, China. One whale shark was at the Atlantis Hotel
Atlantis, The Palm
Atlantis, the Palm is a hotel resort at Palm Jumeirah in Dubai, United Arab Emirates. It is a joint venture between Kerzner International Limited and Istithmar PSJC and was opened on 24 September 2008. The resort is modelled after the Atlantis, Paradise Island resort in Nassau, Bahamas...
in Dubai, but was released in March, 2010.
Reproduction
The capture of a female in July 1996 which was pregnant with 300 pups indicates that whale sharks are ovoviviparousOvoviviparity
Ovoviviparity, ovovivipary, or ovivipary, is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch...
. The eggs remain in the body and the females give birth to live young which are 40 to 60 cm (15.7 to 23.6 ) long. It is believed that they reach sexual maturity at around 30 years and the life span is an estimated 70 to 100 years.
On March 7, 2009, marine scientists in the Philippines discovered what is believed to be the smallest living specimen of the whale shark. The young shark, measuring only 38 centimetres (15 in), was found with its tail tied to a stake at a beach in Pilar, Philippines, and was released into the wild. Based on this discovery some scientists no longer believe that this area is just a feeding ground; it may also be that this site is a birthing ground as well.
Conservation status
The whale shark is targeted by commercial fisheriesFishing industry
The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products....
in several areas where they seasonally aggregate. The population is unknown and the species is considered vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
by the IUCN. In 1998, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
banned all fishing, selling, importing and exporting of whale sharks for commercial purposes, followed by India in May 2001, and Taiwan in May 2007. They are currently listed as a vulnerable species; however, they continue to be hunted in parts of Asia, such as Taiwan and the Philippines.
In 2006, Resorts World Sentosa announced its plans to bring in whale sharks for their marine life park. This was met with opposition from seven notable conservation societies. In 2009, the plan was shelved in favour of a search for other alternatives.
In 2010, the Gulf of Mexico oil spill
Gulf of Mexico oil spill
There have been two major oil spills in the Gulf of Mexico:*The Ixtoc I oil spill, from June 1979 to March 1980*The Deepwater Horizon oil spill, from April 2010 to August 2010...
resulted in 4900000 barrels (779,037,745.5 l) of oil flowing into an area south of the Mississippi River Delta
Mississippi River Delta
The Mississippi River Delta is the modern area of land built up by alluvium deposited by the Mississippi River as it slows down and enters the Gulf of Mexico...
, where one-third of all whale shark sightings in the northern part of the gulf have occurred in recent years. Sightings confirmed that the whale sharks were unable to avoid the oil slick which was situated on the surface of the sea where the whale sharks feed for several hours at a time. However, no dead whale sharks have been found.
.
In human culture
Known as a deity in a VietnamVietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
ese culture, the whale shark is called "Ca Ong", which literally translates as "Sir Fish".
In Mexico, and throughout much of Latin America, the whale shark is known as "pez dama" or "domino" for its distinctive patterns of spots. However, they go by "Sapodilla Tom" in Belize due to the regularity of sightings near the Sapodilla Cayes on the Belize Barrier Reef
Belize Barrier Reef
The Belize Barrier Reef is a series of coral reefs straddling the coast of Belize, roughly offshore in the north and in the south within the country limits...
.
In Africa, the names for the whale shark are very evocative: "papa shillingi" in Kenya came from the myth that God threw shillings upon the shark which are now its spots. In Madagascar the name is "marokintana" meaning "many stars".
Javanese
Javanese language
Javanese language is the language of the Javanese people from the central and eastern parts of the island of Java, in Indonesia. In addition, there are also some pockets of Javanese speakers in the northern coast of western Java...
also reference the stars by calling it "geger lintang," meaning "stars in the back". In the Philippines, it is called "butanding", while in Madurese
Madurese language
Madurese is a language of the Madurese people of Madura Island and eastern Java, Indonesia; it is also spoken on the neighbouring small Kangean Islands and Sapudi Islands, as well as from migrants to other parts of Indonesia, namely the Tapal Kuda area comprising Pasuruan, Surabaya, Malang until...
, it is known as "kikaki".
External links
- Whale Shark Photo-identification Library
- Whale Shark And Oceanic Research Center
- Maldives Whale Shark Research Program
- Report a whale shark sighting
- How to photograph a whale shark for mark-recapture research
- Whale shark research discussion forum
- Whale Sharks: Gentle Giants of the Seas
- Foundation for the Protection of Marine Megafauna
- Whale Shark Project
- Albino whale shark photographed in Galapagos
- A whale shark recorded defecating
- YouTube — Whaleshark