Editing Shark (section)

===Digestion===
Digestion can take a long time. The food moves from the mouth to a J-shaped stomach, where it is stored and initial digestion occurs.<ref name="Digestion">{{cite web
|url=http://elasmo-research.org/education/white_shark/digestion.htm
|title=No Guts, No Glory
|last=Martin
|first=R. Aidan
|publisher=ReefQuest Centre for Shark Research
|access-date=2009-08-22
|archive-url=https://web.archive.org/web/20090811032322/http://www.elasmo-research.org/education/white_shark/digestion.htm
|archive-date=2009-08-11
|url-status=live
}}</ref> Unwanted items may never get past the stomach, and instead the shark either vomits or turns its stomachs inside out and ejects unwanted items from its mouth.<ref>{{cite news|last1=Potenza|first1=Alessandra|title=Sharks literally puke their guts out—here's why|url=https://www.theverge.com/tldr/2017/6/2/15725932/shark-puking-behavior-stress|access-date=21 June 2017|work=[[The Verge]]|date=20 June 2017|archive-url=https://web.archive.org/web/20170619112058/https://www.theverge.com/tldr/2017/6/2/15725932/shark-puking-behavior-stress|archive-date=19 June 2017|url-status=live}}</ref>

One of the biggest differences between the digestive systems of sharks and mammals is that sharks have much shorter intestines. This short length is achieved by the [[spiral valve]] with multiple turns within a single short section instead of a long tube-like intestine. The valve provides a long surface area, requiring food to circulate inside the short gut until fully digested, when remaining waste products pass into the [[cloaca]].<ref name="Digestion"/>