The quillback (Carpiodes cyprinus) is a type of freshwater fish of the sucker family. It grows to 26 in (65 cm) and is deeper-bodied than most suckers, leading to a carplike appearance. It can be distinguished from carp by the lack of barbels around the mouth. Its coloration is silvery and it has large scales. It is called quillback because of the long filament that extends back from the dorsal fin. The species is widely distributed in the eastern and central United States and is found most often in rivers, creeks, and clear lakes where the bottom is loose. It feeds on insect larvae and other organisms in the sediment.
The quillback carpsucker is closely related to the highfin carpsucker and the river carpsucker. All three species are rarely caught by anglers due to their feeding habits, but they have been caught occasionally on worms, minnows, and artificial lures. Quillbacks often comprise a large portion of the biomass of warmwater rivers, but they are very difficult to catch with traditional American angling methods.