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What the sources say

Basking SharkCetorhinus maximus

Every figure, record and mechanism on the Basking Shark profile was written from a source, and this is the working table behind it: 42 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Florida Museum of Natural History, Discover Fishes

Basking Shark, Cetorhinus maximus. Florida Museum of Natural History, Discover Fishes.

The page saysThe second-largest fish on Earth, filtering up to 2,000 tons of seawater an hour through its gills to scoop up zooplankton.
The source saysThis slow-moving migratory shark is the second largest fish, growing as long as 40 feet and weighing over 5 tons. It is often sighted swimming close to the surface, huge mouth open, filtering 2,000 tons of seawater per hour over its complicated gills to scoop up zooplankton.Note: "up to" from the body's 'can strain up to 2000 tons'
The page saysArctic and Temperate Seas Worldwide, Inshore to Offshore
The source saysThe basking shark is a coastal-pelagic species found throughout the world's arctic and temperate waters. ... The basking shark is typically seen swimming slowly at the surface, mouth agape in open water near shore. This species is known to enter bays and estuaries as well as venturing offshore.
The page saysPlanktivore (Zooplankton: Small Crustaceans, Larvae, Fish Eggs)
The source saysThese sharks feed along areas that contain high densities of large zooplankton (i.e., small crustaceans, invertebrate larvae, and fish eggs and larvae).
The page saysEnormous Filter-Feeding Mouth & Up to 2,000 Tons of Water an Hour
The source saysIts enormous mouth extends past the small eyes and contains many small, hooked teeth. ... The basking shark's gill rakers can strain up to 2000 tons of water per hour.
The page saysUp to 2,000 Tons an Hour
The source saysThe basking shark's gill rakers can strain up to 2000 tons of water per hour.Note: heading
The page saysthe second-largest fish alive, behind only the whale shark
The source saysSecond only to the whale shark (Rhincodon typus) in sizeNote: 'second-largest' is the page's 'second only to the whale shark in size'
The page saysIt can grow as long as 12 meters (40 feet) and weigh over 5 tons
The source saysgrowing as long as 40 feet and weighing over 5 tonsNote: 12 m from the source's 40 feet (the page's own conversion elsewhere)
The page saysthe average adult measures 6.7 to 8.8 meters (22 to 29 feet)
The source saysThe average adult length is 22-29 feet (6.7-8.8 m).
The page saysIts enormous mouth extends back past its small eyes.
The source saysIts enormous mouth extends past the small eyes
The page saysIts large gill slits nearly encircle its head, and inside them sit gill rakers, strainers that can sift up to 2,000 tons of seawater an hour.
The source saysFood is strained from the water by gill rakers located in the gill slits. The basking shark's gill rakers can strain up to 2000 tons of water per hour.
The page saysThey catch zooplankton, tiny drifting animals such as small crustaceans, larvae and fish eggs.
The source saysThese sharks feed along areas that contain high densities of large zooplankton (i.e., small crustaceans, invertebrate larvae, and fish eggs and larvae).Note: 'tiny drifting animals' defines zooplankton
The page saysOf the three big filter-feeding sharks, the basking shark is the only one that relies solely on swimming to push water through its mouth. The whale shark and the megamouth shark help the process along by sucking or pumping water in.
The source saysthe basking shark is one of three species of large, filter-feeding sharks. However, the basking shark is the only one that relies solely on the passive flow of water through its pharynx by swimming. ... The whale shark and megamouth shark assist the process by suction or actively pumping water into their pharynxes.
The page saysIts liver can make up 25% of its body weight.
The source saysThe basking shark has a very large liver that accounts for up to 25% of its body weight.
The page saysThe liver is high in squalene, a low-density chemical that helps give the shark near-neutral buoyancy, meaning it neither sinks nor rises easily.
The source saysThe liver is high in squalene, a low-density hydrocarbon that helps give the shark near-neutral buoyancy.Note: 'meaning it neither sinks nor rises easily' defines near-neutral buoyancy; 'chemical' for hydrocarbon
The page saysBasking sharks are found in arctic and temperate waters around the world, and are usually seen near shore, though they also venture offshore.
The source saysThe basking shark is a coastal-pelagic species found throughout the world's arctic and temperate waters. ... The basking shark is typically seen swimming slowly at the surface, mouth agape in open water near shore. This species is known to enter bays and estuaries as well as venturing offshore.
The page saysSlow to Grow
The source saysThe basking shark is an extremely slow-growing speciesNote: heading
The page saysThe basking shark grows extremely slowly and may reach 5 to 6 meters (16 to 20 feet) before it matures.
The source saysThe basking shark is an extremely slow-growing species and may grow to 16-20 feet (5-6 m) before becoming mature.
The page saysFemales are estimated to mature at 12 to 16 years old
The source saysIt has been estimated that females reach sexual maturity between 12-16 years.
The page sayspregnancy lasts three years or longer
The source saysThe gestation period is 3 years or longer.
The page saysSlow growth, late maturity and long pregnancies make the species vulnerable to overfishing.
The source saysbasking sharks are vulnerable to overfishing for several reasons. They have a lengthy maturation time, slow growth rate and a long gestation period.
The page saysA basking shark is generally no danger to people. Its skin, though, is extremely rough
The source saysBasking sharks are passive and no danger to humans in general, but they are large animals and their skin is extremely rough
The page saysits large dermal denticles, the tooth-like scales in shark skin, have been known to injure divers and scientists.
The source saysits large dermal denticles have been known to inflict damage on divers and scientistsNote: 'the tooth-like scales in shark skin' defines dermal denticles
The page saysMany people have seen basking sharks leap from the water, and the reason is not fully understood.
The source saysMany people have witnessed individual sharks leaping from the water. This phenomenon is not fully understood
The page saysSome believe a jump may help a shark get rid of parasites and hitchhikers such as remoras and sea lampreys. A lamprey cannot cut through the shark's armored skin, but it may irritate the shark enough to set off a reaction like jumping.
The source sayssome believe the shark may be trying to rid itself of parasites or commensals such as remoras and especially sea lampreys (Petramyzon marinus), which are often seen attached to the skin of the basking shark. The lamprey cannot cut through the denticle-armored skin, but they may be enough of an irritant to cause a reaction like jumpingNote: 'hitchhikers' for commensals
The page saysA basking shark (Cetorhinus maximus) swims slowly with its huge mouth open, filtering up to 2,000 tons of seawater an hour.
The source saysThis slow-moving migratory shark is the second largest fish, growing as long as 40 feet and weighing over 5 tons. It is often sighted swimming close to the surface, huge mouth open, filtering 2,000 tons of seawater per hourNote: "up to" from the page's 'gill rakers can strain up to 2000 tons of water per hour'
The page saysGill rakers inside its large gill slits strain out zooplankton, such as small crustaceans, larvae and fish eggs, as the water passes through.
The source saysFood is strained from the water by gill rakers located in the gill slits. ... These sharks feed along areas that contain high densities of large zooplankton (i.e., small crustaceans, invertebrate larvae, and fish eggs and larvae).
The page saysNot usually. Basking sharks are not considered dangerous to people who simply watch them, and they generally tolerate divers and boats. Their size and power still deserve respect, and their skin is best not touched: its large dermal denticles have been known to injure divers and scientists.
The source saysBasking sharks are not considered dangerous to the passive observer and are generally tolerant of divers and boats. Despite this, its sheer size and power must be respected (there are reports of sharks attacking boats after being harpooned). In addition, contact with its skin should be avoided, as its large dermal denticles have been known to inflict damage on divers and scientistsNote: 'Not usually' answers the question within 'not considered dangerous to the passive observer'
The page saysIt is not fully understood. Some believe leaping may help a shark get rid of parasites and hitchhikers such as remoras and sea lampreys. A lamprey cannot cut through the shark's armored skin, but it may irritate the shark enough to set off a jump.
The source saysThis phenomenon is not fully understood but some believe the shark may be trying to rid itself of parasites or commensals such as remoras and especially sea lampreys (Petramyzon marinus) ... The lamprey cannot cut through the denticle-armored skin, but they may be enough of an irritant to cause a reaction like jumping

Source
02

AnAge: The Animal Ageing and Longevity Database

Cetorhinus maximus. AnAge: The Animal Ageing and Longevity Database.

The page saysThe longest lifespan recorded for a wild basking shark is 32 years.
The source saysMaximum longevity 32 years (wild)Note: 'longest recorded' is AnAge's 'maximum longevity'

Source
03

Animal Diversity Web, University of Michigan

Cetorhinus maximus (basking shark). Animal Diversity Web, University of Michigan.

The page saysThey migrate mostly according to how much plankton there is.
The source saysBasking sharks migrate mostly based on the abundance of plankton.

Source
04

Rigby et al. 2021

Rigby et al. (2021). Cetorhinus maximus. The IUCN Red List of Threatened Species 2021: e.T4292A194720078.

The page saysThe IUCN Red List rates it Endangered.
The source saysIUCN Red List category: Endangered (EN).

Source
05

Gore et al. 2008

Gore et al. (2008). Transatlantic migration and deep mid-ocean diving by basking shark. Biology Letters.

The page saysScientists had assumed that basking sharks lived in separate populations.
The source saysbasking sharks (Cetorhinus maximus) have been assumed to remain in discrete populations
The page saysThen a 2008 study followed a shark tagged off the British Isles. She travelled 9,589 kilometers while crossing the North Atlantic, and her tag came off near Newfoundland, Canada.
The source saysresults on the tracks and behaviour of two basking sharks tagged off the British Isles, one of which released its tag off Newfoundland, Canada. During the shark's transit of the North Atlantic, she travelled a horizontal distance of 9589 kmNote: 2008 is the paper's year
The page saysIt was the first evidence of a link between European and American populations.
The source saysThis result provides the first evidence for a link between European and American populations
The page saysShe also reached 1,264 meters deep, a record at the time, which indicated that the species uses deep water beyond the edge of the continental shelf
The source saysreached a record depth of 1264 m. This result provides the first evidence for a link between European and American populations and indicates that basking sharks make use of deep-water habitats beyond the shelf edgeNote: 'a record at the time': the 2008 paper's record, not checked against later tagging
The page saystravelled 9,589 kilometers across the North Atlantic and reached 1,264 meters deep, a record in 2008.
The source saysDuring the shark's transit of the North Atlantic, she travelled a horizontal distance of 9589 km and reached a record depth of 1264 m.Note: blockquote restates the body figures; 2008 is the paper's year
The page saysIn a 2008 study, one shark tagged off the British Isles reached 1,264 meters deep while crossing the North Atlantic, a record at the time. The result indicated that the species uses deep water beyond the edge of the continental shelf.
The source saystwo basking sharks tagged off the British Isles ... During the shark's transit of the North Atlantic, she travelled a horizontal distance of 9589 km and reached a record depth of 1264 m. This result provides the first evidence for a link between European and American populations and indicates that basking sharks make use of deep-water habitats beyond the shelf edgeNote: 2008 is the paper's year; 'a record at the time' dates the abstract's 'record depth'

Source
06

Skomal et al. 2009

Skomal et al. (2009). Transequatorial Migrations by Basking Sharks in the Western Atlantic Ocean. Current Biology.

The page saysSharks tagged off southern New England have been tracked to the Bahamas, the Caribbean Sea and on into the Southern Hemisphere. In those waters they descended to the mesopelagic, or twilight, zone, and some stayed there for weeks to months at a time.
The source saysTagged sharks moved from temperate feeding areas off the coast of southern New England to the Bahamas, the Caribbean Sea, and onward to the coast of South America and into the Southern Hemisphere. When in these areas, basking sharks descended to mesopelagic depths and in some cases remained there for weeks to months at a time.Note: 'twilight zone' is the common name of the mesopelagic

Source
07

Sims 2000

Sims (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.

The page saysIn one study that tracked six basking sharks at the surface
The source saysMovements of six basking sharks (4.0-6.5 m total body length, L(T)) swimming at the surface were tracked
The page saysthey swam about 24% slower while filter-feeding than while cruising with their mouths closed
The source saysswimming speeds during filter-feeding were significantly lower than when cruise swimming with the mouth closed, indicating basking sharks select speeds approximately 24% lower when engaged in filter-feeding
The page sayspossibly to avoid the energy cost of extra drag at faster feeding speeds
The source saysThis reduction in speed during filter-feeding could be a behavioural response to avoid increased drag-induced energy costs associated with feeding at higher speeds.
The page saysa shark that swims about 24% slower while filter-feeding than while cruising with its mouth closed
The source saysswimming speeds during filter-feeding were significantly lower than when cruise swimming with the mouth closed, indicating basking sharks select speeds approximately 24% lower when engaged in filter-feedingNote: Settle #387: vibe.reason mechanism replaces 'epic slow-motion oceanic migrations'.

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.