Figure 3. Exploratory measures of zebrafish in the novel tank test (Experiment 1).

There was a significant effect of time on all top measures in the novel tank test. Additionally, 7 days of chronic unpredictable stress (CUS) (A) marginally decreased the number of times zebrafish entered the top zone, (B) significantly decreased the amount of time zebrafish explored the top zone, and (C) slightly (but non-significantly) decreased the distance traveled in the top of the novel tank test over 6 minutes. Thus, all zebrafish tended to explore the top zone more across the duration of the test; however, chronically stressed fish explored less than non-stressed fish (N = 25 in each group).