Editing Shark (section)

==Ecology==
===Feeding===
{{About|shark feeding|the sport of shark feeding|Shark baiting|section=yes}}
[[File:Surfacing great white shark.jpg|A great white shark attacking bait at [[Isla Guadalupe]], Mexico|thumb|right|alt=Photo of great white on surface with open jaws revealing meal.]]

Most sharks are [[carnivorous]].<ref name="Feeding"/> [[Basking shark]]s, [[whale shark]]s, and [[megamouth shark]]s have independently evolved different strategies for filter feeding [[plankton]]: basking sharks practice [[ram feeding]], whale sharks use suction to take in plankton and small fishes, and megamouth sharks make [[suction feeding]] more efficient by using the [[luminescent]] tissue inside of their mouths to attract prey in the deep ocean. This type of feeding requires [[gill raker]]s—long, slender filaments that form a very efficient [[sieve]]—analogous to the [[baleen]] plates of the [[great whale]]s. The shark traps the plankton in these filaments and swallows from time to time in huge mouthfuls. Teeth in these species are comparatively small because they are not needed for feeding.<ref name="Feeding">{{cite web
|url=http://elasmo-research.org/education/topics/d_filter_feeding.htm
|title=Building a Better Mouth Trap
|last=Martin
|first=R. Aidan
|publisher=ReefQuest Centre for Shark Research
|access-date=2009-08-22
|archive-url=https://archive.today/20120710044533/http://elasmo-research.org/education/topics/d_filter_feeding.htm
|archive-date=2012-07-10
|url-status=live
}}</ref>

Other highly specialized feeders include [[cookiecutter shark]]s, which feed on flesh sliced out of other larger fish and [[marine mammal]]s. Cookiecutter teeth are enormous compared to the animal's size. The lower teeth are particularly sharp. Although they have never been observed feeding, they are believed to latch onto their prey and use their thick lips to make a seal, twisting their bodies to rip off flesh.<ref name="Collins" />

Some seabed–dwelling species are highly effective ambush predators. [[Angel shark]]s and [[wobbegong]]s use camouflage to lie in wait and suck prey into their mouths.<ref>{{cite web|url=http://elasmo-research.org/education/shark_profiles/orectolobiformes.htm|title=Order Orectolobiformes: Carpet Sharks—39 species|last=Martin|first=R. Aidan|publisher=ReefQuest Centre for Shark Research|access-date=2009-08-29|archive-url=https://web.archive.org/web/20090429042126/http://elasmo-research.org/education/shark_profiles/orectolobiformes.htm|archive-date=2009-04-29|url-status=live}}</ref> Many [[benthic]] sharks feed solely on [[crustacean]]s which they crush with their flat [[molar (tooth)|molariform]] teeth.

Other sharks feed on [[squid]] or fish, which they swallow whole. The [[viper dogfish]] has teeth it can point outwards to strike and capture prey that it then swallows intact. The [[great white shark|great white]] and other large predators either swallow small prey whole or take huge bites out of large animals. [[Thresher shark]]s use their long tails to stun shoaling fishes, and [[sawshark]]s either stir prey from the seabed or slash at swimming prey with their tooth-studded [[Rostrum (anatomy)|rostra]].

The [[bonnethead]] shark is the only known omnivorous species. Its main prey is crustaceans and mollusks, but it also eats a large amount of seagrass, and is able to digest and extract nutrients from about 50% of the seagrass it consume.<ref>{{Cite journal|title=Seagrass digestion by a notorious 'carnivore'|first1=Samantha C.|last1=Leigh|first2=Yannis P.|last2=Papastamatiou|first3=Donovan P.|last3=German|date=September 5, 2018|journal=Proceedings of the Royal Society B: Biological Sciences|volume=285|issue=1886|pages=20181583|doi=10.1098/rspb.2018.1583|pmid=30185641|pmc=6158537}}</ref>

Many sharks, including the [[whitetip reef shark]] are cooperative feeders and hunt in packs to herd and capture elusive prey. These social sharks are often migratory, traveling huge distances around [[ocean basin]]s in large schools. These migrations may be partly necessary to find new food sources.<ref>{{harvnb|Stevens|1987}}</ref>

===Range and habitat===
Sharks are found in all seas. They generally do not live in fresh water, with a few exceptions such as the [[bull shark]] and the [[river shark]] which can swim both in seawater and freshwater.<ref name="ADW (Bull sharks)">{{cite web
|url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Carcharhinus_leucas.html
|title=''Carcharhinus leucas''
|publisher=University of Michigan Museum of Zoology, Animal Diversity Web
|access-date=2006-09-08
|archive-url=https://web.archive.org/web/20110605105452/http://animaldiversity.ummz.umich.edu/site/accounts/information/Carcharhinus_leucas.html
|archive-date=2011-06-05
|url-status=dead
}}</ref> Sharks are common down to depths of {{convert |2000|m|ft|-3}}, and some live even deeper, but they are almost entirely absent below {{convert |3000|m|ft|-3}}. The deepest confirmed report of a shark is a [[Portuguese dogfish]] at {{convert|3700|m}}.<ref>{{cite journal
 |vauthors=Priede IG, Froese R, Bailey DM, etal |title=The absence of sharks from abyssal regions of the world's oceans
|journal=Proceedings: Biological Sciences
|volume=273
|issue=1592
|pages=1435–41
|year=2006
|pmid=16777734
|pmc=1560292
|doi=10.1098/rspb.2005.3461}}</ref>