Age-0 Lake Sturgeon Prey Selectivity

            Range wide, lake sturgeon populations have declined due to overharvest and habitat degradation. Most efforts to reestablish lake sturgeon populations have been hindered by a host of factors, including incomplete information on the synergistic relationship between early life habitat or needs and foraging ecology. Examination of age-0 lake sturgeon foraging ecology could provide information relating to this knowledge gap and provide necessary information to facilitate rehabilitation for the Upper Mississippi River lake sturgeon population. To determine age-0 lake sturgeon prey selectivity, controlled laboratory experiments were conducted. Age-0 lake sturgeon using three size classes (0-50mm, 51-100mm, and 101-150mm) were separated into individual microcosms. Water quality was maintained similarly among microcosms. Each age-0 lake sturgeon was offered ten-similarly sized (not to exceed gape) of each of three orders of invertebrates (Ephemeroptera, Trichoptera, and Diptera). Foraging activity was monitored for a 24-h period to determine invertebrate consumption. Across size classes, Diptera were preferentially consumed while Trichoptera were generally avoided. Overall, this simple baseline study has provided insight into age-0 lake sturgeon prey selectivity to promote lake sturgeon rehabilitation.