PREDATOR-MEDIATED PLASTICITY IN MORPHOLOGY, LIFE-HISTORY, AND BEHAVIOR OF DAPHNIA - THE UNCOUPLING OF RESPONSES

We studied the way 12 traits responded to fish kairomones in a set of 16 Daphnia magna clones derived from four different habitats-two where daphnids co-occur with fish and two without fish. These clones differ ed widely in their response to predator kairomones, with none of the c lones showing a significant response in all traits and all clones show ing a response for at least one trait. Most of the clones showed a sig nificant response in one to four traits, with no evidence for an assoc iation between different traits. Clones from fish habitats were slight ly more responsive to the presence of fish kairomones than clones from fishless locations. We conclude that most clones show an induced resp onse to the presence of their predators (fish) but that there is a lar ge genetic variability with respect to the traits for which clones sho w a response. Our results indicate that the major distinction is not b etween inducible and noninducible genotypes but rather that the genoty pes differ in the combination of traits for which they show inducible responses.