Editing Shark (section)

===Intelligence===
<!-- This http://www.elasmo-research.org/education/white_shark/structure_brain.htm says much more and should probably be incorporated in the text, but need time to do, keep URL here. -->
Sharks possess brain-to-body mass ratios that are similar to mammals and birds,<ref>{{cite book |title=Sexual segregation in vertebrates |editor-first=Kathreen E. |editor-last=Ruckstuhl |editor-first2=Peter |editor-last2=Neuhaus |publisher=Cambridge University Press |date=January 23, 2006 |page=128 |chapter=Sexual Segregation in Sharks |isbn=978-0-521-83522-0}}</ref> and have exhibited apparent curiosity and behavior resembling play in the wild.<ref>{{cite web
|url=http://www.elasmo-research.org/education/white_shark/intelligence.htm
|title=Is the White Shark Intelligent
|publisher=ReefQuest Centre for Shark Research
|access-date=2006-08-07
|archive-url=https://archive.today/20120801023830/http://www.elasmo-research.org/education/white_shark/intelligence.htm
|archive-date=2012-08-01
|url-status=live
}}</ref><ref>{{cite web
|url=http://www.elasmo-research.org/education/shark_profiles/l_nasus.htm
|title=Biology of the Porbeagle
|publisher=ReefQuest Centre for Shark Research
|access-date=2006-08-07
|archive-url=https://archive.today/20120729183605/http://www.elasmo-research.org/education/shark_profiles/l_nasus.htm
|archive-date=2012-07-29
|url-status=live
}}</ref>

There is evidence that juvenile lemon sharks can use observational learning in their investigation of novel objects in their environment.<ref name="Guttridge">{{cite journal |author1=Guttridge, T.L. |author2=van Dijk, S. |author3=Stamhuis, E.J. |author4=Krause, J. |author5=Gruber, S.H. |author6=Brown, C. |year=2013 |title=Social learning in juvenile lemon sharks, Negaprion brevirostris |journal=Animal Cognition |volume=16 |issue=1 |pages=55–64 |doi=10.1007/s10071-012-0550-6 |pmid=22933179 |s2cid=351363 |url=https://animalstudiesrepository.org/cgi/viewcontent.cgi?article=1085&context=acwp_asie |access-date=2019-09-05 |archive-url=https://web.archive.org/web/20190427122811/https://animalstudiesrepository.org/cgi/viewcontent.cgi?article=1085&context=acwp_asie |archive-date=2019-04-27 |url-status=dead }}</ref>