---
title: "What the sources say about the Whale Shark | AnimalTracks.wiki"
description: "66 claims from the Whale Shark profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/whale-shark-1.webp"
canonical: "https://animaltracks.wiki/animals/whale-shark/sources/"
---

# What the sources say about the Whale Shark (*Rhincodon typus*)

> 66 claims from the Whale Shark profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Whale Shark](https://animaltracks.wiki/animals/whale-shark/)

## Rhincodon typus (whale shark). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Rhincodon_typus/

| The page says | The source says |
| :--- | :--- |
| tooth-like scales | The skin is studded with dermal denticles, which are tooth-like scale structures |
| Warm tropical and subtropical oceans worldwide | Whale sharks are a highly migratory, pelagic species distributed throughout the world's tropical seas ... They are known to inhabit both deep and shallow coastal waters of subtropical zones |
| A whale shark's skin is studded with dermal denticles, tooth-like scales | The skin is studded with dermal denticles, which are tooth-like scale structures |
| A whale shark's pattern of light spots and stripes stays the same for life | composed of light spots and stripes over a dark body ... Coloration remains the same over the shark's lifespan, making it an ideal character for photo identification of individuals. |

## Whale Shark. Georgia Aquarium.

https://www.georgiaaquarium.org/animal/whale-shark/

| The page says | The source says |
| :--- | :--- |
| World's largest fish | The largest fish in the world |
| that filters its food out of seawater | Filters food from the water by “cross-flow filtration,” |
| usually offshore | Habitat Typically found offshore |
| frequents coastal upwelling areas and sometimes enters lagoons and coral atolls | sometimes entering lagoons or coral atolls. Frequents shallow water areas near bays and upwelling coastal areas near continental drop-offs |
| Zooplankton, including sergestid shrimps and fish eggs, plus krill, jellies, copepods, coral spawn, and small fishes such as sardines and anchovies | Consists of zooplankton, specifically sergestid shrimps and fish eggs, as well as krill, jellies, copepods, coral spawn, etc. and small fishes (sardines, anchovies, etc.) |
| The whale shark (Rhincodon typus) is the largest fish alive. | The largest fish in the world (note: a record, so it cites the current institution page; Ong et al. 2020 and Yamaguchi et al. 2023 say the same) |
| A current aquarium profile gives its common length as 18 to 32.8 feet (5.5 to 10 meters) | Common length is between 18 and 32.8 feet (5.5 – 10 m). |
| the largest measured at 61.7 feet (18.8 meters) | The largest measured whale shark was 61.7 feet (18.8 m). (note: the current institution page; ADW's older account gives 20 m (high) and Ong et al. 2020 'up to 18 m') |
| It adds that a living whale shark is "very difficult to weigh accurately." | in life, it is very difficult to weigh accurately |
| A whale shark's teeth are tiny, point backward and are thought to play no role in feeding, though there are about 300 rows of them lining the inside of each jaw. | Teeth are tiny and pointed backward; thought to have no function in feeding. ... There are about 300 rows of tiny teeth along the inner surface of each jaw, just inside the mouth. |
| a mouth up to four feet wide | can reach up to 4ft wide |
| water drains out through the gills while plankton, which carries more momentum, keeps moving toward the back of the mouth | Rather, water is directed away through the gills while particles (which have more momentum) carry on towards the back of the mouth |
| Their threats include entanglement in fishing nets and boat strikes | Specific threats to whale sharks include entanglement in fishing nets, boat strikes, ingestion of marine debris and micro plastics |
| no two sharks' spot patterns are exactly alike, so researchers use them like fingerprints | Individual spot patterns, like human fingerprints, no two are exactly alike. |

## Pierce et al. (2025). Rhincodon typus. The IUCN Red List of Threatened Species 2025: e.T19488A126673248.

https://doi.org/10.2305/iucn.uk.2025-2.rlts.t19488a126673248.en

| The page says | The source says |
| :--- | :--- |
| Endangered | IUCN Red List category: Endangered (EN). (note: stats.conservationStatus) |
| Whale sharks are now listed as Endangered on the IUCN Red List. | IUCN Red List category: Endangered (EN). |

## Ong et al. (2020). Annual Bands in Vertebrae Validated by Bomb Radiocarbon Assays Provide Estimates of Age and Growth of Whale Sharks. Frontiers in Marine Science.

https://doi.org/10.3389/fmars.2020.00188

| The page says | The source says |
| :--- | :--- |
| One 10-meter female, whose vertebrae were studied for a 2020 aging paper, had an estimated weight of about 7,000 kilograms (15,400 pounds). | A 10 m total length (TL) female with an estimated weight of 7000 kg was landed in Karachi, Pakistan in February 2012. (note: paper published 2020 (Front. Mar. Sci., 06 April 2020); 7,000 kg x 2.2046 = 15,432 lb, given as about 15,400 lb) |
| Its authors counted growth bands in the vertebrae of 20 sharks | Counts of growth bands in 20 sharks ranged from 15 to 50 |
| used carbon-14 from 1950s and 60s nuclear bomb tests | Above-ground testing of thermonuclear weapons in the 1950s and 60s increased the ratio of carbon 14 isotopes in the atmosphere that were then mixed into the ocean, passed up food webs and incorporated into marine organisms |
| to confirm that each band marks a year, and estimated ages of up to 50 years | Here, we provide the first validation of the annual formation of growth bands within the vertebrae of the whale shark using bomb radiocarbon assays. Ages of up to 50 years were estimated from sectioned vertebrae |
| The bands narrowed in the oldest sharks | Band width decreased with age, narrowing substantially in the oldest individuals |
| but had not stopped forming | There was no cessation of the formation of growth bands in the vertebrae of older sharks (note: the oldest sharks are among the 'older sharks' the quote covers) |
| Scientists estimate a whale shark's age by counting growth bands in its vertebrae. | the first validation of the annual formation of growth bands within the vertebrae of the whale shark using bomb radiocarbon assays. Ages of up to 50 years were estimated from sectioned vertebrae |
| A 2020 study confirmed that each band marks one year | Here, we provide the first validation of the annual formation of growth bands within the vertebrae of the whale shark using bomb radiocarbon assays. (note: study published 2020 (Frontiers in Marine Science)) |
| by measuring radiocarbon from 1950s and 60s nuclear bomb tests inside the vertebrae | Above-ground testing of thermonuclear weapons in the 1950s and 60s increased the ratio of carbon 14 isotopes in the atmosphere that were then mixed into the ocean, passed up food webs and incorporated into marine organisms. As a result, the timing of the deposition of bands can be validated by comparing carbon isotope values within vertebrae |
| comparing it with a reference record from fish ear stones of known age | we used a reference chronology developed from young known-age otoliths (note: otoliths are fish ear stones) |
| It estimated ages of up to 50 years, and the older sharks were still forming new bands. | Ages of up to 50 years were estimated from sectioned vertebrae ... There was no cessation of the formation of growth bands in the vertebrae of older sharks |

## Motta et al. (2010). Feeding anatomy, filter-feeding rate, and diet of whale sharks Rhincodon typus during surface ram filter feeding off the Yucatan Peninsula, Mexico. Zoology.

https://doi.org/10.1016/j.zool.2009.12.001

| The page says | The source says |
| :--- | :--- |
| 20 filter pads that strain more than 600,000 liters of seawater an hour in a 6-meter shark, by one estimate | The filtering apparatus is composed of 20 unique filtering pads ... it was estimated that a whale shark of 443 cm total length (TL) filters 326 m(3)/h, and a 622 cm TL shark 614 m(3)/h (note: 614 m3/h = 614,000 L/h, so 'more than 600,000 liters'; 622 cm = 6.22 m, given as '6-meter') |
| through 20 filter pads meshed with holes averaging just 1.2 millimeters across | composed of 20 unique filtering pads ... with openings averaging 1.2mm in diameter |
| Cross-flow filtration helps keep that mesh from clogging | A feeding mechanism utilizing cross-flow filtration of plankton is described, allowing the sharks to ingest plankton that is smaller than the mesh while reducing clogging of the filtering apparatus. |
| Off Mexico's Yucatan Peninsula, researchers estimated that a shark about 6 meters long filters more than 600,000 liters of seawater an hour while ram feeding at the surface. | studied off Cabo Catoche, Yucatan Peninsula, Mexico. ... During surface ram filter feeding ... it was estimated that a whale shark of 443 cm total length (TL) filters 326 m(3)/h, and a 622 cm TL shark 614 m(3)/h (note: 622 cm = 6.22 m, 'about 6 meters'; 614 m3/h = 614,000 L/h, so 'more than 600,000 liters') |
| Through cross-flow filtration. | A feeding mechanism utilizing cross-flow filtration of plankton is described |
| Water flows into its mouth, through 20 filter pads meshed with holes averaging just 1.2 millimeters wide, and across the gills. | The filtering apparatus is composed of 20 unique filtering pads that completely occlude the pharyngeal cavity. A reticulated mesh lies on the proximal surface of the pads, with openings averaging 1.2mm in diameter. Superficial to this, a series of primary and secondary cartilaginous vanes support the pads and direct the water across the primary gill filaments. |
| A 2010 study described how this lets the shark swallow plankton smaller than the mesh while reducing clogging. | A feeding mechanism utilizing cross-flow filtration of plankton is described, allowing the sharks to ingest plankton that is smaller than the mesh while reducing clogging of the filtering apparatus. (note: study published 2010 (Zoology); 'allowing' given as 'lets') |
| Its authors estimated that a whale shark about 6 meters long, ram feeding at the surface off Mexico's Yucatan Peninsula, filters more than 600,000 liters of seawater an hour, and that the sharks there spent about 7.5 hours a day feeding on average. | studied off Cabo Catoche, Yucatan Peninsula, Mexico. ... During surface ram filter feeding ... Sharks on average spent approximately 7.5h/day feeding at the surface ... a 622 cm TL shark 614 m(3)/h (note: 622 cm = 6.22 m, 'about 6 meters'; 614 m3/h = 614,000 L/h, so 'more than 600,000 liters') |
| off Mexico's Yucatan, feeds by cruising at about 1.1 meters per second with its mouth open at the surface | During surface ram filter feeding, sharks swam at an average velocity of 1.1m/s with 85% of the open mouth below the water's surface. (note: vibe.reason; replaces 'tranquil ocean drift', a mood (#180). Yucatan scope as in the title and the body) |
| for around 7.5 hours a day | Sharks on average spent approximately 7.5h/day feeding at the surface (note: vibe.reason; same figure as the FAQ) |

## Tomita et al. (2020). Armored eyes of the whale shark. PLOS ONE.

https://doi.org/10.1371/journal.pone.0235342

| The page says | The source says |
| :--- | :--- |
| armored in tooth-like scales down to its eyeballs | including the discovery that they are covered with dermal denticles, which is a novel mechanism of eye protection in vertebrates |
| Dermal denticles that armor its eyeballs | including the discovery that they are covered with dermal denticles, which is a novel mechanism of eye protection in vertebrates |
| that also cover its eyes | including the discovery that they are covered with dermal denticles |
| A 2020 study counted about 2,900 of these eye denticles around the iris of one shark's eye | Numerous dermal denticles are distributed on the eye surface around the iris ... the total number of eye denticles was ca. 2900 in OCF-P04248 (note: study published 2020 (PLOS ONE); OCF-P04248 is one eyeball taken from a dead bycatch shark) |
| shaped differently from the denticles on the rest of the body in a way consistent with resisting abrasion | The eye denticle differs in morphology from that of the dermal denticles distributed over the rest of the body, consistent with a different function (abrasion resistance) |
| observed three captive whale sharks | Eye retraction behavior was observed in all whale sharks (specimens A–C) examined in this study (note: specimens A-C are three; A and B lived in an exhibition tank at Okinawa Churaumi Aquarium and C in an open-water fish pen beside it) |
| pull their eyes back into their sockets in under a second when a diver approached, by up to about half the eyeball's diameter | When an object approached (in this case the diver), the eyes were retracted into the orbit with a duration (from the onset of eye retraction to complete retraction) of less than 1 s. Ultrasound data showed that the maximum retraction distance was 3.3 and 2.8 cm (50.4 and 49.8% of the eyeball diameter) |
| The authors knew of no other shark or ray with denticles on its eyes. | As far as we know, eye denticles have not been found in other elasmobranchs, including species closely related to the whale shark (note: elasmobranchs are sharks and rays) |
| Whale sharks have no eyelids, so the surface of the eye is less protected than the rest of the body, which is covered in dermal denticles. | Considering that these tissues are exposed and that whale sharks lack eyelids; the eye surface is less protected from mechanical damage than other regions of the body that are covered with mineralized dermal denticles. |
| A 2020 study found denticles on the eyes too, about 2,900 of them around the iris of one shark's eye | Numerous dermal denticles are distributed on the eye surface around the iris ... the total number of eye denticles was ca. 2900 in OCF-P04248 (note: study published 2020 (PLOS ONE); FAQ 1 restatement of the body's count) |
| shaped differently from the ones on the rest of the body in a way consistent with resisting abrasion | The eye denticle differs in morphology from that of the dermal denticles distributed over the rest of the body, consistent with a different function (abrasion resistance) |
| The authors say they are probably useful in reducing the risk of damage to the eye's surface. | the covering of the eye surface with denticles in the whale shark is probably useful in reducing the risk of mechanical damage to the eye surface |
| The same study observed three captive whale sharks pull their eyes back into their sockets in under a second when a diver approached, by up to about half the eyeball's diameter. | When an object approached (in this case the diver), the eyes were retracted into the orbit with a duration (from the onset of eye retraction to complete retraction) of less than 1 s. Ultrasound data showed that the maximum retraction distance was 3.3 and 2.8 cm (50.4 and 49.8% of the eyeball diameter) (note: specimens A-C, captive at or beside Okinawa Churaumi Aquarium (see the body claim)) |

## Womersley et al. (2021). Wound-healing capabilities of whale sharks (Rhincodon typus) and implications for conservation management. Conservation Physiology.

https://doi.org/10.1093/conphys/coaa120

| The page says | The source says |
| :--- | :--- |
| Researchers following injured whale sharks in photographs from two Indian Ocean aggregation sites | The present study makes use of a unique and valuable photographic data source from two whale shark aggregation sites in the Indian Ocean. |
| estimated that the wounds reached 90 percent closure by about day 35 overall, 22 days for scrapes and 50 for cuts | All wounds reached a point of 90% surface area closure by Day 35. There were differences in healing rate based on wound type, with lacerations and abrasions taking 50 and 22 days to reach 90% healing, respectively. (note: the 35 days is the x-intercept (34.84 days) of an exponential model fitted to all wounds (Fig. 9), so 'estimated ... overall'; lacerations are cuts, abrasions scrapes) |
| One juvenile male, first seen in 2006 missing the tip of his first dorsal fin, appeared about five years later to have regrown it | a juvenile male from the Djibouti aggregation was sighted in 2006 missing the tip of the first dorsal fin. When this individual was re-sighted approximately 5 years later (2011) it appeared to have re-grown the previously amputated first dorsal fin tip |
| which the authors called the first reported case of a shark or ray regrowing part of an appendage | This is the first reported case of an elasmobranch re-growing a part of an appendage (note: elasmobranchs are sharks and rays) |

## Brunnschweiler et al. (2009). Deep-diving behaviour of a whale shark Rhincodon typus during long-distance movement in the western Indian Ocean. Journal of Fish Biology.

https://doi.org/10.1111/j.1095-8649.2008.02155.x

| The page says | The source says |
| :--- | :--- |
| One tagged off Mozambique dove to 1,286 meters, deep into the mesopelagic and bathypelagic zones, while covering at least 1,200 kilometers of ocean in 87 days. | a minimum distance of 1200 km in 87 days. Dives to depths well into the mesopelagic and bathypelagic zones (1286 m maximum depth) were recorded |

## Yamaguchi et al. (2023). Whale shark rhodopsin adapted to deep-sea lifestyle by a substitution associated with human disease. Proceedings of the National Academy of Sciences.

https://doi.org/10.1073/pnas.2220728120

| The page says | The source says |
| :--- | :--- |
| Whale sharks also dive far below the surface. | The whale shark, which dives into the deep sea of nearly 2,000 meters besides near-surface filter feeding |
| The whale shark's eye pigment, rhodopsin, absorbs light best at 478 nanometers | uncovered a remarkable shift of the wavelength of the maximum absorbance (λmax) to 478 nm (note: RHO is rhodopsin) |
| close to the light of about 480 nanometers that fades least in the deep sea | the light of approximately 480 nm is the least attenuated in the deep sea (note: 'fades least' for 'least attenuated') |
| A 2023 study traced that tuning mostly to one spot in the pigment, site 94 | our spectroscopy of recombinant whale shark RHO mutants revealed that this blue shift is caused dominantly by an unprecedented spectral tuning site 94 (note: study published 2023 (PNAS); 'caused dominantly' given as 'mostly'; the blue shift itself was 'previously shown', so the 2023 finding is its cause) |
| the same site where, in humans, a mutation causes a form of night blindness | In humans, the mutation at the site causes congenital stationary night blindness (CSNB) by reducing the thermal stability of RHO |

## Arzoumanian, Holmberg & Norman (2005). An astronomical pattern-matching algorithm for computer-aided identification of whale sharks Rhincodon typus. Journal of Applied Ecology.

https://doi.org/10.1111/j.1365-2664.2005.01117.x

| The page says | The source says |
| :--- | :--- |
| A 2005 study adapted a computer algorithm originally built for comparing star patterns in pictures of the night sky to match photos of whale shark spots. | spot patterns captured in photographs of whale shark flanks have been used, in the past, to make identifications by eye. We have automated this process by adapting a computer algorithm originally developed in astronomy for the comparison of star patterns in images of the night sky. (note: paper published 2005 (Journal of Applied Ecology)) |
| Tested on pictures of sharks that had already been identified, it matched the correct pairs more than 90 percent of the time. | In tests using a set of previously identified shark images, our method correctly matched pairs exhibiting the same pattern in more than 90% of cases. |