Fin margins in breeding males become a reddish orange, and their underlying body pattern becomes concealed with suffused black pigment.

The bottom is consistent with gravel and sand substrates, scattered with large rocks and mats of vegetation.

Although the Pygmy Sculpin are found throughout the spring, they are least common over sandy substrates, with the exception of juveniles usually occurring in low current areas over gravel bottom.

Pygmy sculpin diet consists primarily of small invertebrates, with isopods serving as a year-round food source.

Seasonally, pygmy sculpins also consume gastropods, amphipods, snails, and occasionally eggs of their own species.

Spawning occurs year round but peaks during a time period between the months of April to August.

Eggs are laid in clumps of 1-9 on the underside of rocks and bricks within these cavities and range from pale yellow to orange.

While females do not engage in maternal care, males guard nest sites until hatching occurs.

The last assessment, on November 10, 2011, designated this status based on the species' limited range (under 100 square km), occurrence in a single location, and deteriorating water quality.