Differential Prey Vulnerability and Predator Selectivity: Effects of Evasive Prey on Bluegill (Lepomis macrochirus) and Pumpkinseed (L. gibhosus) Predation

Abstract

Sunfish will select Daphnia preferentially over copepods even though the apparent size of the copepods may be considerably larger. This selectivity is probably the result of the fishes having learned differences in the evasion capabilities of the two different prey types, and having translated this into a differential selectivity. Sunfish have the ability to correlate information about the evasion capabilities of prey with visual appearances of the prey, and to select less evasive prey. Such information may have considerable significance in defining the observed selectivity of these fish in nature, and such behavioral responses should be considered in future modeling efforts.Key words: predation, Lepomis, selectivity, behavior