View source for Cookiecutter shark

[[File:Mike Spalding.jpeg|400px|thumb|right|[[Michael Spalding]], renowned Hawaiian Islands [[channel swimmer]], in hospital recovering from a bite from a [[cookiecutter shark]] in the [[Alenuihaha Channel]] between the [[Big Island of Hawaii]] and [[Maui]]]]
[[File:Cookiecutter.jpeg|400px|thumb|right|Cookiecutter shark]]noun - The cookiecutter shark (Isistius brasiliensis), also called the [[cigar shark]], is a species of small dogfish shark that lives in warm, oceanic waters worldwide, particularly near islands, and has been recorded swimming as deep as 3.7 km (2.3 mi). It migrates vertically up to 3 km (1.9 mi) every day, approaching the surface at dusk and descending with the dawn. Reaching only 42–56 cm (17–22 in) in length, the cookiecutter shark has a long, cylindrical body with a short, blunt snout, large eyes, two tiny spineless dorsal fins, and a large caudal fin. It is dark brown in color, with light-emitting photophores covering its underside except for a dark "collar" around its throat and gill slits.

The name "cookiecutter shark" refers to its feeding habit of gouging round plugs, like a cookie cutter, out of larger animals including [[great white shark]]s. Marks made by cookiecutter sharks have been found on a wide variety of marine mammals and fishes, as well as on submarines, undersea cables, and even human bodies including [[Michael Spalding]], a [[marathon swimmer]] swimming between Hawaii and Maui in the state of Hawaii. 

It also consumes whole smaller prey such as squid. Cookiecutter sharks have adaptations for hovering in the water column and likely rely on stealth and subterfuge to capture more active prey. Its dark collar seems to mimic the silhouette of a small fish, while the rest of its body blends into the downwelling light via its ventral photophores. When a would-be predator approaches the lure, the shark attaches itself using its suctorial lips and specialized pharynx and neatly excises a chunk of flesh using its bandsaw-like set of lower teeth. This species has been known to travel in schools.

Though rarely encountered because of its oceanic habitat, a handful of documented attacks on humans were apparently caused by cookiecutter sharks. Nevertheless, this diminutive shark is not regarded as highly dangerous. The International Union for Conservation of Nature (IUCN) has listed the cookiecutter shark under Least Concern, as it is widely distributed, has no commercial value, and is not particularly susceptible to fisheries.

==External links==

* [https://www.openwaterswimming.com/absolutely-heroic-shark-attack-survivor-adherbal-de-oliveira-is-first-to-complete-the-lpsa-triple-crown/ Absolutely Heroic! Shark Attack Survivor Adherbal de Oliveira Is First To Complete The LPSA Triple Crown]
* [https://www.openwaterswimming.com/pet-dont-punch-at-least-with-lemon-sharks/ Pet, Don't Punch...At Least With Lemon Sharks]
* [https://www.openwaterswimming.com/2020/02/adherbal-treidler-de-oliveira-is-2019-world-open-water-swimming-man-of-the-year/ Adherbal Treidler de Oliveira Is 2019 World Open Water Swimming Man Of The Year]
* [https://www.openwaterswimming.com/2020/02/2019-wowsa-award-winners-announced/ 2019 WOWSA Award Winners Announced]
* [https://www.openwaterswimming.com/2019/07/adherbal-de-oliveira-hit-by-cookiecutter-shark-in-molokai/ Adherbal de Oliveira Hit By Cookiecutter Shark In Molokai Channel]
* [https://www.openwaterswimming.com/2019/08/florin-tomos-matt-buckman-on-crossing-the-molokai-channel/ Florin Tomos, Matt Buckman On Crossing the Molokai Channel]
* [https://www.openwaterswimming.com/2019/08/matt-manoa-buckman-heroes-in-the-ocean/ Matt & Manoa Buckman, Heroes In The Ocean]
* [http://10kswim.blogspot.com/2009/03/mike-spalding-one-tough-cookie/ Mike Spalding, One Tough Cookie]
* [https://www.openwaterswimming.com/2017/03/it-takes-very-special-swimmer-to-try/ It Takes A Very Special Swimmer To Try Again]
* [https://www.openwaterswimming.com/2013/01/tough-cookiesround-shark-bites-from-deep/ Tough Cookies...Round Shark Bites From The Deep]
* [http://www.openwatersource.com/mike-spalding.html Mike Spalding on Open Water Wednesday]
* [http://news.ufl.edu/2011/06/30/cookiecutter-shark/ Cookiecutter Shark Research Study]
* [https://www.openwaterswimming.com/2011/07/studying-shark-attack-on-mike-spalding/ Studying Shark Attacks]
* [https://www.openwaterswimming.com/2011/06/mike-spalding-on-open-water-wednesday/ Mike Spalding]
* [https://www.openwaterswimming.com/2013/05/shark-in-pacific-caught-up-in-atlantic/ Shark In The Pacific Is Caught Up In The Atlantic]
* [https://www.openwaterswimming.com/2013/09/shark-encounter-leaves-tooth/ Shark Encounter Leaves A Tooth In Charlotte Brynn]
* [https://www.openwaterswimming.com/2015/05/absolutely-painful-open-water-swims-of/ Absolutely Painful Open Water Swims Of The 21st Century]
* [https://www.openwaterswimming.com/2015/08/shark-encounters-in-channels-around/ Shark Encounters In Channels Around The World]
* [https://www.openwaterswimming.com/2016/07/how-do-you-define-open-water-swimming/ How Do You Define Open Water Swimming?]
* [http://www.wowsa.org World Open Water Swimming Association]
* [http://www.imshof.org International Marathon Swimming Hall of Fame]
* [http://www.marathonswimming.com Marathon Swimming]
* [http://olympics.openwaterswimming.com/ Olympic 10K Marathon Swim] 
* [http://www.openwaterswimming.com Daily News of Open Water Swimming]
* [http://www.igotstung.com I Got Stung]
* [http://www.worldmarathonswimmingassociation.com World Marathon Swimming Association]
* [http://www.imshof.org International Marathon Swimming Hall of Fame]
* [https://www.openwaterswimming.com/2016/07/surfing-and-swimming-adventurers-weigh/ Ocean Adventurers Weigh Risks And Rewards]
* [https://www.openwaterswimming.com/2016/07/shark-spawning-season-in-september/ Shark Spawning Season In September]
* [https://www.openwaterswimming.com/2017/10/linda-kaiser-honored-by-hall-of-fame/ Linda Kaiser Honored By Hall Of Fame]
* [https://www.openwaterswimming.com/2018/12/linda-kaiser-lived-life-of-aloha/ Linda Kaiser Lived A Life of Aloha]

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