Date of Graduation

Summer 2008

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Alicia Mathis

Keywords

copper, foraging, alarm, darter, sub-lethal

Subject Categories

Biology

Abstract

Heavy metal toxicants can have deleterious effects on aquatic organisms, including decreased activity levels and foraging efficiency, and inhibition of sensory systems. For fishes in the genus Etheostoma (darters), toxicological tests have included lethal effects of copper, but sub-lethal effects on behavior have not been well studied. This thesis examines the sub-lethal effects of chronic copper exposure on foraging activity and alarm behavior of rainbow darters, E. caeruleum. Groups of darters were exposed to low (~18 μg/L) and high (~36 μg/L) concentrations of waterborne copper over a period of 28 days. Foraging trials were then conducted in the presence and absence of alarm pheromones during a period of 1-4 days following removal from the copper-treated water. Darters exposed to the high levels of copper showed a significant decrease in number of prey eaten and foraging efficiency, and an increase in time to consume all prey compared to the low level treatment. Darters exposed to the alarm pheromone during trials showed a significant decrease in number of moves and an increase in time to consume all prey in comparison to darters that were not exposed to the alarm pheromone. There was a significant interaction effect between copper and alarm treatments on time to consume all prey, indicating that copper exposure may decrease the magnitude of response to an alarm pheromone.

Copyright

© David A. Woods, Jr.

Campus Only

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