Results from each experiment showing the number of prey added (ind), mean number of prey removed (ind ± 1 standard error), mean prey survivorship, and two-way ANOVA results (F-value).

Prey added represents the number of initially stocked individuals per trial. Prey removed represents the number of individuals remaining in the tank after each trial, and the prey survivorship is the number of prey recovered divided by the number of prey added. Expt 1 used a fixed number of predator and prey individuals across treatments of variable levels of structural complexity. Expt 2 used the same structural treatments as the first experiment, but scaled the density of prey across treatments. Expt 3 used the same prey density treatments as the second experiment, but altered the amount of ‘predator-free space’ (by increasing interstitial space) in each structural treatment. Control treatments had no structure. * p