It is an inhabitant of small and medium rivers where it occurs in rocky riffles with clear, fast-flowing water.

Within Canada, the river darter is native to southern regions including the Hudson Bay basin, Ontario, and Manitoba.

Within the United States, the river darter is native to a band that starts northward in Canada and extends into Minnesota and North Dakota and continues to the Gulf drainages in Alabama and Texas.

[6] Males are darker and more distinctly marked during spawning season, but do not develop bright colors like many other darters.

Tubercles develop on the caudal, pelvic and anal fins, and occasionally also occur on the heads of males during the breeding season.

[6] The river darter relies on frictional contact with the substratum to maintain its position while minimizing its energy usage.

The river darter's enlarged pectoral fins help create negative lift and increase the friction between its body and the ground to counteract turbidity.

[7] Adult individuals feed on a wide variety of all aquatic invertebrates such as midge and caddisfly larvae, which are common in streams and rivers.

Chironomids, trichopteras, and small crustaceans are other key elements of the adult diet of river darters.

Primarily food sources for juveniles include small zooplankton floating in their freshwater habitats.

[7] The river darter attains much of its adult size during the first year of development, and reaches sexual maturity by the age of one.