Marissa Wold

Date of Award

January 2018

Document Type


Degree Name

Master of Science (MS)



First Advisor

Tristan Darland


Cadmium is a naturally-occurring trace metal frequently found in soil that has been linked with increased prevalence of various cancers via formation of reactive oxygen species. Selenium, a widely-prevalent metalloid, antagonizes the detrimental action of cadmium and has been demonstrated to exert a rescue effect. The present work focuses on the short- and long-term effects of exposure to ecologically-relevant cadmium concentrations on zebrafish development and behavior, and compares this to co-treatment with selenium. This study has demonstrated a decrease in overall brain size, specifically telencephalic area, in response to cadmium exposure, and has documented a sparing effect of selenium treatment. A similar effect is seen in larval body size and eye diameter. This study has also reported an effect on spinal morphology and hatching delay. Longitudinally, cadmium treatment affects survival to six months, and has an impact on adult brain metrics. The results of behavioral assay indicate an effect of larval cadmium exposure on adult learning behavior, as well as a rescue effect of selenium.