Date Approved


Graduate Degree Type


Degree Name

Health Sciences (M.H.S.)

Degree Program

Biomedical Sciences

First Advisor

Daniel Bergman

Second Advisor

Shkelzen Shabani

Third Advisor

Christopher Lawrence

Academic Year



It is well established in the scientific community that decapod crustaceans secrete molecules via nephropores to communicate with each other. These molecules have been shown by numerous conducted studies to affect the animal behavior, especially aggression. However, studies in decapods crustaceans have yet to elucidate the chemical nature of aggressive chemosignals during agonistic interactions. The main goal of this study was to identify the chemical profile of crayfish urine via HPLC during two conditions: when stressed and while fighting. The urine analysis of stressed crayfish showed that uric acid, guanosine, L-tryptophan, and N-acetylserotonin were present in the samples, minutes after the stressful conditions. On the other hand, the analysis of the water collected near the crayfish during the aggressive altercations revealed that xanthine, dopamine, and L-tryptophan were present in the samples. Also, an unknown molecule, which was only present in the intra-fight sample and not in any other sample, was detected during the chemical investigation. Its chemical composition and secretion source remains to be found.