Kayla McRobb

Date Approved


Degree Type

Open Access Thesis

Degree Name

Master of Science (MS)

Department or School


Committee Member

Ulrich Reinhardt-Segawa

Committee Member

Steven Francoeur

Committee Member

Cara Shillington


The bloom-forming alga Microcystis produces the hepatotoxin microcystin-LR. Removing this toxin from drinking water requires expensive treatments; current analytical methods are incapable of real-time monitoring. Crayfish are resistant to microcystin-LR toxicity and respond well to operant conditioning. I hypothesized that crayfish could sense and be trained to respond to microcystin-LR via electroshocks for use as biomonitors. In the microcystin detection experiment, Procambarus clarkii moved away from microcystin-LR (p < 0.001) while Orconectes rusticus did not respond (p = 0.28). Neither species could be reliably trained to move to the tank’s center when microcystin-LR was present. To understand why, I tested Procambarus clarkii’s ability to respond to a neutral scent using positive and negative reinforcement. They associated the scent with positive reinforcement (p < 0.001) but not negative reinforcement (p = 0.21), suggesting crayfish may be incapable of associating scents with negative tactile stimuli.

Included in

Biology Commons