Female adult zebrafish ( Danio rerio ) show higher levels of anxiety‐like behavior than males, but do not differ in learning and memory capacity

Zebrafish ( Danio rerio ) are widely used as a translational model for human neuropsychiatric conditions. Many studies have not considered sex differences in their analyses. Here, we studied sex differences of adult zebrafish in two behavioral domains: Anxiety and Memory. To assess whether sex influences anxiety‐like responses, we used two different behavioral protocols, the novel tank diving task and the light–dark test. To assess sex differences in learning and memory tasks, we explored two memory domains, short‐term spatial memory (free movement pattern Y‐maze task) and short‐term fear memory (Pavlovian fear‐conditioning task). Although we did not find any significant difference in learning and memory tasks, female zebrafish showed robust increases in anxiety‐like behavioral endpoints in both anxiety tests. Overall, our data suggest that zebrafish is a sensitive model to work with sex differences when modeling anxiety‐related disorders and this should be an important factor to consider in different experimental designs.