Size-Dependent Diel Foraging Periodicity of a Mayfly Grazer in Streams with and without Fish

• DOI: 10.2307/3544836
• Publication Date: 2006-11-16T18:13:11Z
• Authors: Joseph M. Culp; Garry J. Scrimgeour
• Keywords: Diel vertical migration; Cobble

We tested the hypothesis that predation risk from diurnal fish influences diel foraging periodicity of mayfly grazer, Baetis tricaudatus Dodds, in a size-dependent manner by examining habitat use and activity mayflies streams with without these predators. In each stream was determined counting number small (3 mm total length) large (6 larvae on upper surfaces replicate, natural cobble during 4-8 sampling periods within 24-h cycle over three seasons. Additionally, were collected preserved so dial gut fullness could be