Spiders on the clock: the ecological implications and neurohormonal underpinnings of circadian rhythm in foraging and antipredator behavior

East Tennessee State University, Johnson City TN

Investigators

Abstract

Nearly all living things, including humans, have daily biological rhythms. This "internal clock" helps regulate physiological and behavioral changes over the course of a twenty-four hour period. This study will test the hypothesis that the internal clock conveys an advantage to individuals by allowing them to anticipate, and adjust to, changing conditions. The project will explore connections between rhythms in aggression and wariness and the internal clock in orb-weaving spiders. Spiders are a particularly good model organism for such work because they are both predators and prey, and, thus, must balance aggression and wariness to be successful. Spiders are also practical because their behaviors are easily measured and experimentally altered. Initially, this study will describe the relative influences of the internal clock and external cues of a variety of aggression-related behaviors. The role of brain chemistry and in regulating aggression will also be studied by measuring hormone levels in individuals. Finally, this study will test how daily changes in aggression levels relate to changes in the organism's environment. This work will provide much-needed insight into the regulation of behavioral rhythms, and how the environment influences them. Along with gains in basic research, this project will provide substantial educational opportunities for students in the Southern Appalachian region. This project will support three graduate students and provide six summer fellowships for undergraduate students.