Comparing behavioral responses across multiple assays of stress and anxiety in zebrafish (Danio rerio)

Animals encounter stressful situations multiple times throughout their lives and often successfully cope with them. Individuals vary in the nature and intensity of their behavioral and physiological response to stressors, often representing correlated and qualitatively distinct coping styles (e.g., proactive and reactive). These alternative coping styles are ways an animal can overcome a variety of stressful situations, which ultimately can have important fitness consequences. Here we use zebrafish (Danio rerio) recently wild-derived and selectively bred for amount of stationary behavior (High and Low lines) and a classic domesticated strain (AB) to document the utility of these zebrafish strains in understanding coping mechanisms. The Low Stationary Behavior (LSB) line of zebrafish displayed significantly lower stress and anxiety-related behaviors than the High Stationary Behavior (HSB) across six stress and anxiety-related behavioral assays. In some assays, we observed strain differences in behavior within three minutes of the start of the trial. Males also showed reduced levels of anxiety-related behaviors relative to females in two assays. Comparing wild-derived and domesticated strains, the AB line displayed significantly lower levels of anxiety-related behavior in half of the assays. This study demonstrates that our selectively bred lines from wild-caught zebrafish (HSB, LSB) exhibit consistent and divergent behavioral stress responses across multiple distinct assays. Hence these lines may prove useful in understanding the proximate and ultimate mechanisms of coping with stress and anxiety.