Populations are common and well established in riffles and raceways of the Snake, the lower reaches of the Sunrise, and the St. Croix above the dalles. These populations have survived mainly because of the extremely low sediment loads and lack of impoundment in the Upper St. Croix basin. Gilt darters exhibit strong sexual dimorphism in size, coloration, and the presence of breeding tubercles. The back of the fish and the lateral blotches become an intense, iridescent blue-green, while the ventral portions of the body and head, the spinous dorsal fin and the area between the blotches become brilliant yellow and orange, the latter sometimes punctuated with reddish dots. At the height of the breeding season, the orange body color is further punctuated by an intense blue-black pigment that accumulates in the breast, in the pelvic and spinous dorsal fins and at the base of the anal fin.
Females show only slight hints of the seasonal color changes that are so striking in males.
The former lacks the gilt darter's dorsal banding pattern and instead exhibits a vermiform pattern of light and dark pigmentation. The latter possesses 4 distinctive black spots in the membrane of the spinous dorsal fin-one between the first and second spines and one following each of the last three spines. Minnesota gilt darters most closely resemble populations from the Ohio River drainage with respect to general body shape and cheek squamation. Gilt darters typically exhibit a seasonal migration between habitats. In the fall, they move from shallow riffles and raceways to the deep chutes of rubble and boulder riffles, where they overwinter.