Stream fishes are vulnerable to a range of natural and anthropogenic stressors. Information on fish movements and habitat use is essential to conserve and manage these populations, and is particularly limited for populations that occupy range boundaries and novel habitats. Neosho Smallmouth Bass Micropterus dolomieu velox occurs only in the southwestern Ozark Highlands ecoregion, where the riverscape is highly dissected by impoundments. I sought to broaden the knowledge of Neosho Smallmouth Bass (NSMB) ecology by evaluating movement patterns, nesting and rearing habitat use at multiple scales, and spawning phenology in relation to physicochemical conditions. Adult NSMB movements were greatest during the spring spawning period and were positively related to discharge and fish size, though I also observed considerable variability among individuals and streams. Tagged fish did not use the reservoir or associated interface habitats. I also documented nest "clustering" by NSMB in response to local habitat conditions; cluster presence was more likely in warmer streams with wide, shallow channels, and less likely in groundwater-gaining reaches. Nest abundance was greater in warmer streams and reaches with deeper pools. I observed spatiotemporal variation in the hatch timing and growth rate of age-0 NSMB in response to discharge and stream temperature conditions. I showed the importance of warmer streams and of deep pools in small streams for NSMB rearing. I also demonstrated the harm of July floods for first-year survival in these populations, and showed the importance of stream proximity (i.e., adjacency to larger streams) for mitigating this effect and modifying the habitat relationships of age-0 NSMB. Lastly, we observed juvenile NSMB movements were greater for larger individuals and with warmer water temperatures. Individual variation was high for both movement and microhabitat use. The variability in movement, habitat use, and response to physicochemical conditions among individuals and populations (i.e., in different streams) underscores the importance of maintaining habitat heterogeneity and streamflow sufficient to connect important habitats, especially in small streams. Protecting the inherent diversity of these populations is crucial for their persistence in a changing environment
