Longhead darters have a series of black blotches down their side that are connected by a broad lateral stripe. Their blotches are never taller than they are wide. They differ from the very similar dusky and blackside darters in having a series of 3 dark spots along their jaw line on each side of the head. The largest and most posterior of these often connects with a rather distinct tear drop forming a dark crescent from the eye down to the rear of the jaw. Longhead darters also have a narrow dusky band in their first dorsal fin near the base of the fin. The rest of their fins have many small spots often forming rows. This species of darter never has bright colors on their body. They are typically 2-3 inches long (sometimes up to 4 inches) and are members of the Percidae (perches and darters) family.

Longhead darters spawn in spring. They lay their eggs in riffles burying them in sand or gravel. They provide no further parental care for the eggs or young.

Longhead darters are found in rather fast moving streams and rivers. They are typically found in pools and riffles with swift current near boulders or cobble sized rocks. In Ohio only 7 longhead darters have ever been found. All of these individuals were found in the Walhonding River in Coshocton County. Typical foods include insect larvae, crustaceans, and other aquatic invertebrates.