The habitats of the different Heptageniidae genera may overlap and there is no clear line dividing the living environments of the different species. As a rule of a thumb, Epeorus, Ecdyonurus and Rhithrogena, prefer faster current. Moving toward the upper Rhithron these three genera will become more and more common, and in the Crenon they become the only mayfly present. Moreover some species live only above specific altitudes, like Epeorus alpicola that is found only starting at 1000 meters above sea level.
In the picture genus Epeorus.