Substrate Associations and Longitudinal Distributions in Species of Ephemerellidae (Ephemeroptera:Insecta) from Western Oregon

Abstract

Substrate associations and longitudinal distributions are described for 12 species of Ephemerellidae. Habitat specialization seems to have been a major means of adaptive radiation within this family. All species showed restrictive use of available habitats: sand-gravel, cobble, boulder, or moss. Patterns of longitudinal distribution may be, in part, a consequence of the specificity that species show for different substrates.