McLeod, Hayley (University of South Carolina, Columbia). Mentor: Kristine Grayson (University of Virginia). The role of maternal effects and the larval environment on developmental plasticity in a pond breeding amphibian.

Abstract: In organisms without parental care, maternal decisions can still have a direct effect on the fitness of offspring. In amphibians, the selection of oviposition site and non-genetic maternal effects provisioned to eggs in response to the laying environment can play an important role in larval success. Unlike many other amphibians that lay a single large clutch, female Eastern red-spotted newts, Notophthalmus viridescens , wrap their eggs singly in vegetation. This study examined the egg laying response to predator variation in the maternal environment and the developmental outcome of variation in both the maternal and larval environments. Maternal environment was manipulated in field enclosures with a control, a heterospecific predator, and a conspecific predator treatment. Larval environment was manipulated through chemical cues from the maternal environments added to the water of the developing egg. Data was collected on egg-laying behavior and larval morphology. The results of this study show that female newts usually wrap their eggs and lay high in the water column, whether in the presence of a predator or not. The larvae from mothers in the control group hatched earlier and had significantly smaller tail heights than larvae laid in a predator environment. The main effect of the larval treatment showed that larvae developed in control water had significantly smaller tail heights than those developed in the presence of predatory chemical cues. However, no differences were found between treatments in either total length or tail length. . This research demonstrates the importance of environmental cues on development, both in the maternal and larval development environment.