Brian D. S. Graeb
Steven R. Chipps
Robert A. Klumb
William E. French
2014
<p><span>Predation can play an important role in the recruitment dynamics of fishes with intensity regulated by behavioral (i.e., prey selectivity) and/or environmental conditions that may be especially important for rare or endangered fishes. We conducted laboratory experiments to quantify prey selection and capture efficiency by three predators employing distinct foraging strategies: pelagic piscivore (walleye </span><i class="EmphasisTypeItalic ">Sander vitreus</i><span>); benthic piscivore (flathead catfish </span><i class="EmphasisTypeItalic ">Pylodictis olivaris</i><span>) and generalist predator (smallmouth bass </span><i class="EmphasisTypeItalic ">Micropterus dolomieu</i><span>) foraging on two size classes of age-0 pallid sturgeon: large (75–100 mm fork length [FL]) and small (40–50 mm FL). Experiments at high (> 70 nephalometric turbidity units [NTU]) and low (< 5 NTU) turbidity for each predator were conducted with high and low densities of pallid sturgeon and contrasting densities of an alternative prey, fathead minnow </span><i class="EmphasisTypeItalic ">Pimephales promelas.</i><span> Predator behaviors (strikes, captures, and consumed prey) were also quantified for each prey type. Walleye and smallmouth bass negatively selected pallid sturgeon (Chesson’s α = 0.04–0.1) across all treatments, indicating low relative vulnerability to predation. Relative vulnerability to predation by flathead catfish was moderate for small pallid sturgeon (α = 0.44, neutral selection), but low for large pallid sturgeon (α = 0.11, negative selection). Turbidity (up to 100 NTU) did not affect pallid sturgeon vulnerability, even at low density of alternative prey. Age-0 pallid sturgeon were easily captured by all predators, but were rarely consumed, suggesting mechanisms other than predator capture efficiency govern sturgeon predation vulnerability.</span></p>
application/pdf
10.1007/s10641-013-0166-y
en
Springer
Vulnerability of age-0 pallid sturgeon <i>Scaphirhynchus albus</i> to predation; effects of predator type, turbidity, body size, and prey density
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