Risk effects on copepods: Preliminary experimental evidence for the suppression of clutch size by predatory early life-history fish

Abstract

Using egg numbers per clutch as a measure of potential reproductive output, the risk effects of zooplanktivorous early life-history fish on the calanoid copepod, Pseudodiaptomus hessei, were investigated in an in situ estuarine mesocosm experiment. Two treatments were established, one with zooplanktivores and one without. The average clutch size of fecund P. hessei females was consistently lower in the presence of predators, despite the elevated food resources (total chlorophyll a concentrations) available in this treatment. © The Author 2013. Published by Oxford University Press. All rights reserved.