Dolphinsaremarinemammalsthatarecloselyrelatedtowhalesandporpoises.Therearealmostfortyspeciesofdolphinin17genera.Theyvaryinsizefrom1.2m(4ft)and40kg(90lb)(Maui'sdolphin),upto9.5m(30ft)and10tonnes(9.8longtons;11shorttons)(theorcaorkillerwhale).Theyarefoundworldwide,mostlyintheshallowerseasofthecontinentalshelves,andarecarnivores,mostlyeatingfishandsquid.ThefamilyDelphinidaeisthelargestintheCetaceanorder,andevolvedrelativelyrecently,abouttenmillionyearsago,duringtheMiocene.Dolphinsareamongthemostintelligentanimals,andtheiroftenfriendlyappearanceandseeminglyplayfulattitudehavemadethempopularinhumanculture.
Dolphinsaremarineanimalsconsideredamongthemostintelligentanimals.Theyeatmostlyfishandsquid.Theiroftenfriendlyappearanceandplayfulattitudehavemadethempopularinthehumanculture.Dolphinsarewellknownfortheiragilityandplayfulbehavior,makingthemafavoriteofwildlifewatchers.Manyspecieswillleapoutofthewater,spy-hop(riseverticallyoutofthewatertoviewtheirsurroundings)andfollowships,oftensynchronizingtheirmovementswithoneanother.