Date of Award

Summer 8-2011

Degree Type

Masters Thesis

Degree Name

Master of Arts (MA)



Committee Chair

David Echevarria

Committee Chair Department


Committee Member 2

Stan Kuczaj

Committee Member 2 Department


Committee Member 3

Virgil Zeigler-Hill

Committee Member 3 Department



Individual differences (IDs) in zebrafish (Danio rerio) behavior were examined across time and contexts in order to investigate personality traits. Zebrafish (N = 30) were exposed to six behavioral tasks that were collectively expected to capture (a) aggression, (b) boldness/shyness, and (c) fear. The tasks included a small open field, mirror exposure, emergence, large open field, novel object, and predator exposure tasks. IDs in behavior were found to be consistent across time for a majority of behaviors and consistent across contexts for all but two behaviors. Convergent and discriminate evidence was examined for the three constructs. There was little evidence for an aggressive trait, which may largely be attributed to the behaviors chosen for measurement in this study. There were mixed results for identifying a separate bold vs. fearless construct; however, results largely indicate that the emergence, novel object, and predator exposure tasks may all have been capturing a tradeoff between boldness and fear. Results suggest that responses to novel objects depend on the object used (the basis for which is still unknown), suggesting that more research needs to be done to determine how best to utilize a novel object task for this species. Although the results from this project did not allow for specific traits to be labeled with confidence, the predator task demonstrated high internal consistency and may be particular useful for capturing fear/anxiety-like traits. Overall, this study provides a comprehensive examination of zebrafish behavior, support for consistent IDs and personality traits, and a much-needed foundation for further personality research in a key model organism, the zebrafish.