Meeting Abstract

P2.83  Monday, Jan. 5  Predator induced plasticity in spotted salamanders DWYER, Laurel A*; LANDBERG, Tobias; University of Connecticut laurel.dwyer@uconn.edu

During metamorphosis, amphibians may be particularly vulnerable because they lack the specialized anti-predator responses of either aquatic larvae or terrestrial adults. This project was designed to study predator-induced plasticity in the spotted salamander, Ambystoma maculatum, at metamorphosis to determine if individuals could reduce their predation risk by changing their behaviors in lethal predation trials or by increasing the rate of metamorphosis. Salamanders were raised in two treatments: with a fish predator (genus Lepomis) on the other side of a divided tank, or without fish cues. Surprisingly, during the larval stage the predator treatment group experienced extremely high mortality rates which raised new questions about the indirect effects of predators on development. Behavioral trials revealed that predator-treatment animals ate less than those not exposed to fish and had lower body mass for their developmental stage. This suggests that reduced feeding rates lead to decreased body condition which, in turn, increases mortality. Exposing predator-naive animals to predator cues induced an immediate drop in feeding rates. However, predator-exposed animals placed into predator-free water did not increase their feeding rates in the same time frame. Thus fish predators have both an immediately inducible as well as a lasting effect on salamander feeding rates. The duration and onset of metamorphosis are still being studied to determine if there are differences between treatments.