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

Abstract

Abstract – A combination of radio telemetry and surface observations were used to characterize the movements and habitats of greater redhorse, Moxostoma valenciennesi, after spawning in the Grand River, Ontario, Canada. This river supports a large population of greater redhorse that migrate upstream in the spring to spawn on riffles. After spawning, greater redhorse moved as far as 15.2 km downstream of spawning areas and maintained summer home ranges in low 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 were usually located over cobble/gravel substrates that were covered with Cladophora. Although interspecific associations with golden redhorse, M. erythrurum, 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 throughout the summer did not change, until relocation to overwintering areas occurred in early autumn.