The redline darter (Etheostoma rufilineatus) is a species of darter endemic to the southeastern United States. This fish, like most other darter species, tends to inhabit clear, rocky riffles of streams, creeks, and small rivers. Both currently and historically, this fish is known from only the Tennessee and Cumberland River drainages in Tennessee, Virginia, Kentucky, Alabama, North Carolina, Georgia, and Mississippi. The average length for this fish is 6.9 cm, with a maximum recorded length of 8.4 cm. The maximum recorded life span in the wild for this species is four years. The redline darter feeds mainly on aquatic macroinvertebrates, including midge fly, black fly, and caddisfly larvae, as well as water mites and mayfly nymphs. These fish spawn in the spring and early summer, from May