The Redside Dace is a coolwater species found in pools and slow flowing areas of small headwater streams with a moderate to high gradient. Overhanging grasses and shrubs, as well as undercut banks, are an important part of their habitat, as are instream boulders and large woody debris. Substrate is variable and includes silt, gravel and boulders.

The Redside Dace is a very colourful minnow. It has a large mouth with a protruding lower jaw. Adults develop a wide, bright red stripe along the front half of the body; a bright yellow stripe above extends to near the tail fin. Fish mature at around two years of age and reach a maximum length of 12 cm. In May, spawning occurs in shallow riffle areas and eggs are often deposited in the nests of other minnows. There is no parental care; however, the nest-guarding male and the nest itself may provide some protection to the eggs. The lifespan of the Redside Dace is generally four years or less.