A small-bodied cladoceran (Moina micrura) reacts more strongly to vertebrate than invertebrate predators: A transgenerational life-table approach

Abstract

We exposed the small-bodied cladoceran Moina micrura either to fish (vertebrate) or to Chaoborus (invertebrate) kairomones for three consecutive generations. We hypothesized that reactions to Chaoborus should be stronger than reactions to fish kairomones. Significant effects of predators and number of generations exposed to a predator were observed in size at primipara, clutch sizes and neonate body lengths. However, stronger responses were detected in females exposed to fish. For intrinsically small-bodied species such as Moina, resource allocation shifts favoring somatic growth might not be effective against invertebrate predators. Thus, our study highlights the relevance of evolutionary and developmental constraints imposed by a small body size that prevents the formation of certain types of defences. © 2011 The Author. Published by Oxford University Press.