The spotfin shiner has a black blotch of pigment on the membrane between its last three rays of the dorsal fin; this spot may be obscure or faint in small spotfin shiners. They are deep-bodied and have a black vertical bar posterior to their operculum. Their mouths open in the terminal position, they have diamond-shaped scales, and each scale is outlined with black pigment. Breeding males become heavily pigmented and steel bluish in color during late spring and early summer, and they have ventral fins that also become dull yellow to bright yellow. The head of spotfin shiners are covered with small tubercles, and they feel rough, almost like sandpaper. Spotfin shiners also have 37-39 lateral line scales. Spotfin shiners have eight anal fin rays unlike its close relative, the satinfin. Cyprinela spiloptera inhabit all but one of the Great Lakes (Superior), and are found from the Saint Lawrence drainage, Quebec to the Potomac river drainage, Virginia. They also inhabit areas from Ontario and New York to North Dakota, as well as south to Alabama and eastern regions of Oklahoma. C. spiloptera are also located in isolated areas of the Ozark mountains. C. spiloptera are freshwater, benthopologic fishes that prefer temperate climates. They inhabit sand and gravel runs and pools of creeks, as well as small to medium rivers with clear, permanent flow.
