PARENT SESSION
Oral Session # 95: Predator - Prey Ecology III: Aquatic Systems.
Presiding: J Vonesh
Friday, August 8. 8:30 AM to 12:00 PM, SITCC Meeting Room 201.

Predator cues in aquatic systems: the dynamics of cue concentration.

Marko, Adam^*,1, Auld, Josh¹, Hoverman, Jason¹, Relyea, Rick¹, ¹ University of Pittsburgh, Pittsburgh, PA, USA

ABSTRACT- Many prey have evolved the ability to detect the presence of predators in their environment. In aquatic systems, prey have been shown to adaptively eavesdrop on recent predation events and subsequently adjust their phenotype to better match their environment. Understanding the concentration dynamics (production and breakdown) of chemical cues can elucidate these nonlethal aspects of predation and assist in understanding the mechanisms of predator-induced phenotypic plasticity. We used a common pond snail, Helisoma trivolvis, to analyze to the characteristics of the chemical cues associated with predation. By crushing conspecifics we were able to induce behaviors similar to those induced by crayfish (Orconectes rusticus). We found that snails are sensitive to cue concentration in a continuous fashion rather than using a threshold response. Peak responses occurred within 5 hrs and the cue was completely degraded within 14 hrs. Freezing the cue had no negative impact on the activity of the chemical cue, suggesting that freezing helped to retard degradation. These results demonstrate that chemical cues can be highly dynamic in aquatic systems and that prey can detect and respond to a wide range of cue concentrations.

Key words: behavioral plasticity, predator cues, aquatic snails, Architeuthis