[2] The johnny darter is found from Saskatchewan and Colorado to the Atlantic seaboard and from Hudson Bay south to the Gulf Coast drainage systems.

[2] These small, slender fish have brown to yellow scales, paler sides, and whitish bellies.

[4] On the fish, the opercles (or bony areas forming the gill covers) have scales, whereas the preopercles (bone at the start of the cheek), napes, and breasts are scaleless.

As it grows, the fish start eating larger waterfleas, different types of larvae, including midges, mayflies, and caddisflies, and the occasional sideswimmer.

[2] These darters are generally eaten by larger predatory fish, such as burbots, lake trout, smallmouth bass, walleyes, and yellow perch.

Spawning occurs in the shallow water, pools and slow runs, with large rocks, logs, cans, shells, or other debris.

The male will guard the nest and keep them oxygenated and will eat the ones that develop fungus until the embryos hatch, which is after about six to 10 days.