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What the sources say

Cookiecutter SharkIsistius brasiliensis

Every figure, record and mechanism on the Cookiecutter Shark profile was written from a source, and this is the working table behind it: 41 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

Kyne 2018

Kyne (2018). Isistius brasiliensis. The IUCN Red List of Threatened Species 2018: e.T41830A2956761.

The page saysThe IUCN Red List rates the species Least Concern.
The source saysIUCN Red List category: Least Concern (LC).
The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus

Source
02

Carlisle et al. 2021

Carlisle et al. (2021). Integrating multiple chemical tracers to elucidate the diet and habitat of Cookiecutter Sharks. Scientific Reports.

The page saysTropical and subtropical oceans worldwide
The source sayswidely distributed throughout the world’s tropical and subtropical oceanic waters
The page saysplus squid
The source saysIn terms of general prey types, stomachs included ~ 49% cephalopods (beaks, tissues)
The page saysIt also eats squid, and many squid remains found in cookiecutter stomachs were estimated to come from squid often as large as the sharks themselves.
The source saysit appears that sharks will consume small squid whole, many of the squid remains were estimated to be from relatively large squid, often as large as the sharks themselves
The page saysCookiecutter sharks live in tropical and subtropical oceans around the world.
The source sayswidely distributed throughout the world’s tropical and subtropical oceanic waters
The page saysFifteen caught off Hawaii in 2013 weighed 213 g on average.
The source saysCookiecutter sharks (n = 15; 9 M, 6 F; mean TL = 33.5 cm ± 6.6 SD; min TL = 17.1 cm, max TL = 43.1 cm, mean mass = 213 g ± 113 SD) were collected off Hawaii in August and September of 2013
The page saysweightKg: 0.213
The source saysmean mass = 213 gNote: battleStats.weightKg

Source
03

Minaglia & Liegl 2024

Minaglia & Liegl (2024). Moonless night sky increases Isistius species (cookiecutter shark) and live human contact. PLOS ONE.

The page saysOf the six bites by cookiecutter sharks (genus Isistius) on live people in Hawaiian waters, five came with the moon set and after dark.
The source says5 of the 6 Isistius spp . bites on live humans in Hawaiʻian waters occurred with the moon set and after nautical twilight end and before nautical twilight start.Note: 'after dark' paraphrases after nautical twilight end and before nautical twilight start; genus scope carried in the sentence
The page saysA 2024 study counted seven confirmed attacks on live people ever documented, six of them in Hawaiian waters between 2009 and 2023.
The source saysOut of 7 ever-documented and confirmed attacks on live humans, 6 occurred in Hawaiʻian waters between the years 2009 and 2023
The page saysVery rarely.
The source sayscontact with live humans is exceedingly rare
The page saysdangerLevel: Medium
The source saysOut of 7 ever-documented and confirmed attacks on live humansNote: stats.dangerLevel

Source
04

Florida Museum of Natural History

Cookiecutter Shark (Isistius brasiliensis). Florida Museum of Natural History.

The page saysglows underneath to lure big animals close
The source saysThe light underside glows, attracting fish, whales, and sharks.
The page saysthen spins to cut a round plug out of them
The source saysthe small shark spins its body removing a cookie-shaped plug from the flesh of its prey
The page saysdeep by day and near the surface at night
The source saysFound in deep water at depths below 3,281 feet (1000 m) during the day, cookiecutter sharks migrate vertically to surface waters at night to feed
The page saysPlugs of flesh cut from large fish, whales and seals
The source saysCommon prey items include large fishes such as marlin, wahoo, dolphin, tuna, sharks, and stingrays as well as marine mammals including seals, whales, and dolphins.
The page saysA glowing underside that lures big animals in, then a spin that carves out a cookie-shaped plug
The source saysThe light underside glows, attracting fish, whales, and sharks. It attaches itself to the prey and uses its serrated bottom teeth to cut out a perfectly circular chunk of flesh.
The page saysIts underside is covered in photophores, tiny light-producing organs that give off a greenish glow
The source saysnetwork of tiny light-producing organs called photophores (Klimley. 2013). Photophores produce an even greenish colored glow on the underside of this shark.
The page saysThe only gap on the underside is a dark collar around the gill region.
The source saysThere is a distinct dark brown collar around the gill region. The entire ventral surface of the cookiecutter shark with the exception of the dark collar contains a network of tiny light-producing organs
The page saysThe glow attracts fish, whales and sharks, and it appears similar to a small fish.
The source saysThe glowing area appears similar to a small fish from the depths, prompting larger fish to approach in search of their next meal.
The page saysThe glow attracts fish, whales and sharks
The source saysThe light underside glows, attracting fish, whales, and sharks.
The page saysThe shark bites when they come close.
The source saysJust prior to biting the cookiecutter shark, the large fish is unexpectedly bitten by the shark.
The page saysIt grips with sucking lips and upper teeth, then spins its body to cut a cookie-shaped plug out of its prey with its larger lower teeth.
The source saysattaches itself to its prey with its sucking lips and sharp pointy upper teeth. Once it is attached, the small shark spins its body removing a cookie-shaped plug from the flesh of its prey with its larger serrated bottom teethNote: 'serrated' left out: the 2018 PLOS ONE genus paper says the lower teeth are not serrated
The page saysThe prey is left with a perfectly round, cookie-cutter-shaped hole in its side.
The source saysThe prey is left with a perfectly round cookie cutter-shaped hole in the side of its body
The page saysThe Florida Museum lists marlin, wahoo, tuna, sharks, stingrays, seals, whales and dolphins among its prey.
The source saysCommon prey items include large fishes such as marlin, wahoo, dolphin, tuna, sharks, and stingrays as well as marine mammals including seals, whales, and dolphins.
The page saysThere are even reports of crater marks on the sonar domes of nuclear submarines.
The source saysThere are reports of this shark leaving crater marks on the sonar domes of nuclear submarines.
The page saysThey are found from the Bahamas to southern Brazil in the western Atlantic, and from Mauritius to New Guinea, New Zealand, Japan and the Hawaiian Islands in the Indo-Pacific.
The source saysfound in the western Atlantic Ocean from the Bahamas south to the coast of southern Brazil ... the Indo-Pacific from Mauritius to New Guinea, Lord Howe Island, and New Zealand north to Japan and east to the Hawaiian Islands
The page saysBy day they stay below 1,000 m. At night they rise to the surface waters to feed, a daily trip scientists call vertical migration.
The source saysFound in deep water at depths below 3,281 feet (1000 m) during the day, cookiecutter sharks migrate vertically to surface waters at night to feed
The page saysthe Florida Museum considers the shark harmless to humans because of its size and deep-water habits
The source saysBecause of its size and deep water habits, it is considered harmless to humans.
The page saysThe teeth are connected at the base and lost as one complete unit, rather than one at a time like most sharks.
The source saysThe teeth are interconnected at the bases, allowing the entire row of teeth to move if one tooth is touched (Compagno. 2005). The teeth are lost as a complete unit rather than individual teeth common to most sharks.
The page saysIt swallows its shed lower teeth, which is thought to help maintain the calcium in its body.
The source saysAs the lower teeth are shed, they are ingested by the shark. This is thought to aid in maintaining the calcium levels in the body
The page saysA litter holds 6 to 12 live young.
The source saysThere are 6-12 live young born per litter
The page saysIt sheds its lower teeth as one complete set and swallows them. The Florida Museum says this is thought to help the shark keep up its calcium levels.
The source saysAs the lower teeth are shed, they are ingested by the shark. This is thought to aid in maintaining the calcium levels in the body
The page saysThe small, cigar-shaped shark can be called a parasite, because it feeds on larger animals without killing them.
The source saysIt can be considered a parasite due to its nature to feed on larger animals without killing them
The page saysThe cookiecutter shark turns its own belly into a lure.
The source saysPrey items are attracted to the ventral surface of the cookiecutter shark due to the light given off by the glowing photophores
The page saysA cookiecutter shark grips with its lips and upper teeth, then spins its body to cut a round plug out of its prey
The source saysthe small shark spins its body removing a cookie-shaped plug from the flesh of its preyNote: vibe.reason
The page saysA cookiecutter shark grips with its lips and upper teeth, then spins its body to cut a round plug out of its prey
The source saysattaches itself to its prey with its sucking lips and sharp pointy upper teethNote: vibe.reason

Source
05

FishBase

Isistius brasiliensis (Quoy & Gaimard, 1824) Cookie cutter shark. FishBase.

The page saysA shark up to 56 cm long that glows underneath to lure big animals close
The source saysfemales mature at 39 cm, with a maximum length of 56 cm
The page saysMales grow to a maximum of 42 cm and females to 56 cm.
The source saysMales mature at about 36 cm, with a maximum length of 42 cm; females mature at 39 cm, with a maximum length of 56 cm.
The page saysFishBase gives a maximum total length of 56 cm for a female and 42 cm for a male.
The source saysMales mature at about 36 cm, with a maximum length of 42 cm; females mature at 39 cm, with a maximum length of 56 cm.
The page saysFemales are the larger sex.
The source saysMales mature at about 36 cm, with a maximum length of 42 cm; females mature at 39 cm, with a maximum length of 56 cm.

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.