Spawning Season and Habitat Use of Slimy Sculpin (Cottus cognatus) in Southeastern Minnesota

Slimy sculpin (Cottus cognatus) in Winona County, Minnesota spawned in late March and early April when water temperature reached 10°C. Relatively large rocks were preferentially used for spawning, and individual nests contained clutches from as many as nine females. Although artificial rock shelters were not used for spawning, large shelters were used for cover more often and small shelters less often than expected if shelter use was random with respect to shelter size. Use of shelters of different sizes did not differ significantly between large and small sculpins.