Zooplankton Selection by Young Yellow Perch: The Influence of Light, Prey Density, and Predator Size

Abstract

Abstract A study to examine the influence of light, prey density, and fish size on prey selection by age-0 yellow perch Perca flavescens was conducted at Oneida Lake, 1982–1983. Our approach was to design laboratory experiments resembling events in the lake and to compare experimental results with field observations. Both laboratory and field results demonstrated that young yellow perch ate smaller prey when light intensity increased. Under low light, young yellow perch detected and ate only the larger-bodied daphnids and fed on a broader array of prey species as light intensity increased. Above 230 1x, size selection for zooplankton was independent of prey abundance and depended mostly on fish size. A prey-selection model was developed to predict the median size of prey selected based on light intensity, fish size, percent Daphnia sp. in the environment, and prey density. At light intensities less than 230 1x, the variables of light, fish size, and percent daphnia contributed significantly (R2 = 0.34; P ...