Coloration for both sexes is olive to brown-black above, brown or pink on the sides, and white to yellow on the belly. Breeding males become black or brown above and develop an orange side-band and a bright yellow belly. Current populations in Arizona are limited primarily to Lakes Mead, Mohave, and Havasu on the lower Colorado River. In medium to large reservoirs, prefers deep pools, often up to 50 feet deep. Breeding occurs in late winter to early summer and occurs over gravelly bottoms in the mainstream or at the confluence of rivers.
Females breed repeatedly with numerous males.
Eggs are transparent, adhesive, and are deposited in spaces between the gravel. Young hatch in a few days and move to the shoreline for a time. Despite successful reproduction, nonnative fishes eat larvae before reaching adulthood. Dewatering of rivers and predation by nonnative fishes are still major concerns.