If the water becomes stagnant or polluted, food supplies are diminished and compromise the darters' ability to survive. Because of their sensitivity to pollution, darters serve as good indicators of water quality. The typical life expectancy for darters is about three to four years. Most reach sexual maturity at one year of age, although egg production increases with age. Mature females of some darter species can produce up to 1,000 eggs.
Darters exhibit a variety of spawning behaviors.
The females of some species attach their eggs to underwater vegetation or rocks. In still other darter species, the male takes an active role, building a nest to attract one or more females. Female spotted darters deposit eggs in a wedge-shaped mass under rocks, which are then guarded by the males. This guarding of the eggs by males is a common trait among several darter species. The bluebreast darter exhibits a rather unique spawning behavior.