Post-spawn movements and habitat use by greater redhorse, Moxostoma valenciennesi

A combination of radio telemetry and surface observations were used to char acterize the movements and habitats of greater redhorse, Moxostoma valencie nnesi, after spawning in the Grand River, Ontario, Canada. This river suppo rts a large population of greater redhorse that migrate upstream in the spr ing to spawn on riffles. After spawning, greater redhorse moved as far as 1 5.2 km downstream of spawning areas and maintained summer home ranges in lo w velocity runs. Mean (+/-SE) water depth used by greater redhorse was 46.3 +/-0.9 cm, and water velocities were less than 5 cm/s. Greater redhorse wer e usually located over cobble/gravel substrates that were covered with Clad ophora. Although interspecific associations with golden redhorse, M. erythr urum, common carp, Cyprinus carpio, smallmouth bass, Micropterus dolomieu, and northern hog sucker, Hypentelium nigricans, were observed, most greater redhorse associated with conspecifics. Areas and habitat types used throug hout the summer did not change, until relocation to overwintering areas occ urred in early autumn.