Percina kusha is distinguished from all other described species of Percina by a combination of the following characteristics: absence of bright colors on body and fins of adults; no orange band in spinous dorsal fin; no broad vertical bands on body extending dorsally across the back joining those of the other side; 7–11 lateral blotches connected to form a continuous dark brown to black lateral stripe with undulating margins; lateral stripe continuous with large, quadrate basicaudal blotch that extends onto base of caudal fin rays; small, dark blotch on upper and lower portion of caudal fin base, dorsal blotch typically darker; body below lateral stripe white to cream colored, without dark blotches, dusky in breeding males; suborbital bar absent or very poorly developed; lateral line complete, typically no pored scales on base of caudal fin; males with row of modified scales on midline of belly and one or two modified scales between base of pelvic fins; modified breast scale absent; nuptial tubercles absent; anal fin of breeding males not excessively elongate; males without caudal keel as a ventral extension of the caudal peduncle; snout not projecting beyond anterior margin of upper jaw; well-developed premaxillary frenum; serrae on margin of preopercle absent; branchiostegal membranes overlapping or very narrowly joined (Ref. 58738).