The fathead minnow, Pimephales promelas, is native to much of North America, but is not native to Utah. In Utah, the species is established in the Colorado River system, and it may also occur in Utah Lake.
The fathead minnow is an opportunistic feeder that eats plant matter, small animals, and detritus. The species spawns throughout the spring and summer; males build nests and guard the eggs until they hatch, which usually takes about five days. Many adults die after spawning is complete. The fathead minnow is considered to be an excellent forage fish, but the species may do a great deal of harm in Utah because it competes with many rare fish species native to the Colorado River system.