PARENT SESSION
Oral Session #46: Animal Community Ecology: Pools, Foodwebs, Structure. Presiding: D. Post.
Wednesday, August 8, 2001. 8:00 AM to 12:00 PM. Hall of Ideas I.
Phenotypic plasticity in frogs: pre-and post-metamorphic environments determine the final frog phenotype.
Hoverman, Jason1, Relyea, Rick1, 1
ABSTRACT- Numerous studies have demonstrated the importance of phenotypic plasticity by focusing on the performance of environmentally-induced phenotypes across a range of environments in a given developmental stage. However, heterogeneous environments likely affect phenotypes at several ontogenetic stages and phenotypes induced early in ontogeny may have lasting effects later in ontogeny. The goal of this study was to explore how both larval predator and competitor environments affect the post-metamorphic morphology and performance of gray treefrogs (Hyla versicolor). Tadpoles were reared under a factorial combination of competitors and predators to induce changes in the larval phenotypes and then allowed to metamorphose to assess subsequent differences in metamorph morphology. Following metamorphosis, the metamorphs from each treatment were reared for an additional month under low and high terrestrial competition to determine if differences in metamorph morphology affected metamorph performance and whether terrestrial competition could further alter frog morphology. We found that even though tadpoles responded to both competition and predation, only competition had an effect on the morphology of newly-emerged metamorphs. However, these morphological difference had no effect on post-metamorphic growth. Finally, terrestrial competition altered the morphology of the frogs. We have shown that larval plasticity has a direct effect on larval traits and an indirect effect on the traits of the newly-emerged metamorphs. However, these traits have no impact on the subsequent growth performance of the metamorphs in the terrestrial environment.
KEY WORDS: phenotypic plasticity, ontogeny, terrestrial performance, Hyla versicolor