GREGG A. SNEDDEN AND WILLIAM E. KELSO, School of Forestry, Wildlife, and Fisheries, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA

Although spotted gar Lepisosteus oculatus are ecologically important in terms of their impact on trophic structure of aquatic communities, little is known about their basic ecology. We used radiotelemetry to determine movement and habitat use for 39 fish in the Atchafalaya River basin. Median (m) daily movement rates were greater during the spring flood-pulse (m=123.92 m/d) than during fall/winter (m=22.80 m/d) or summer (m=34.58 m/d). Median diel movements were greater in summer (m=40.42 m/h) than in fall/winter (m=15.13 m/h), and night movement (m=29.32 m/h) was greater than day movement (m=17.42 m/h), regardless of season. Spotted gar preferred fallen trees and avoided littoral stretches without cover. Permanent water bodies within the river-floodplain system were used during fall/winter and summer, and fish did not stray from initial capture sites. During the spring flood-pulse, fish showed lateral migration onto seasonally inundated floodplain habitats or to vegetation-rich backwater regions. Home ranges were restricted during summer (10.4 hectare) and fall/winter (5.7 hectare), but were larger during the spring flood-pulse (296.1 hectare). These data show the importance of backswamp and seasonally inundated floodplain habitats to spotted gar during spring, and the spatial extent of their use of these regions.