Predator-Induced Phenotypic Plasticity in Organisms with Complex Life Histories

TLDR

Predator‑induced phenotypic plasticity, affecting life‑history, morphology, and behavior, is common in organisms with complex life histories, especially during the larval stage, and models predict changes in size and timing of metamorphosis in response to predation risk. The study proposes that future research should examine larval growth, morphology, behavior, and size‑specific mortality under predation to better understand plasticity. Empirical surveys show that theoretical predictions of predator‑induced changes in metamorphic traits are largely supported, though no single model dominates and some unexpected results, such as the direct costs of morphological changes, remain unpredicted.

Abstract

▪ Abstract Predator-induced phenotypic plasticity is widespread in nature and includes variation in life history, morphology, and behavior. In organisms with complex life histories, predator-induced phenotypic plasticity in the larval period has been widely documented. Several models predict how organisms should alter their size at and time to metamorphosis in response to an increased risk of predation. A survey of empirical studies finds that these theoretical predictions are frequently met. However, no one model performs the best. Additionally, there are several results not predicted by any model. Predator-induced plasticity in metamorphic traits may be related to predator-induced changes in larval morphology and behavior. Predictions of predator effects on larval traits are generally met, except for direct costs of predator-induced morphological phenotypes. Future work should incorporate more detailed studies of growth rate, morphology, and behavior during the larval period, as well as studies of size-specific mortality rates in the presence and absence of predators.