The gilt darter is a fairly opportunistic feeder, its diet varying seasonally depending on the availability of aquatic insect larvae, such as caddisfly larvae, diptera larvae and mayfly nymphs (3) (7) (8). This species also exhibits seasonal migration between different habitats, moving from shallow riffles in the autumn to deeper channels between rubble and boulder riffles in the winter. Mature gilt darters return to the shallower riffles in the late spring and early summer to spawn (3).
The timing and duration of spawning is determined mainly by the effects of temperature and flow of the streams the gilt darter inhabits (3), although it generally begins between late April and May, depending on the location (3) (8). The gilt darter spawns over gravel and sand, in areas free from silt and other debris. It buries the eggs in the substrate, and the eggs hatch after eight to ten days (3). The female typically breeds between the ages of two and three years (8).
During the breeding season, the male gilt darter will establish a territory around cobble or boulder stones. The male aggressively defends its territory, chasing away rival males and deterring intruders using ritualized body posturing, tail beating, fin displays and rapid colour changes (3).