Experimental design and behavioural assessments. (A) Zebrafish eggs were collected immediately after fertilization and microinjected with either 0, 1 or 10 ng venlafaxine. Eggs were raised to either 60 dpf, and assessed for behaviour, or until 10–12 months post-fertilization and assessed for behaviour, metabolic rate, and swim performance. A top-down camera view was utilized for Novel tank (B) and Novel object (C) assessments. An air stone (blue) was the novel object (C) placed in the aquarium. (D) Lateral view behavioural assessment was carried out with the camera placed on the same surface of the tank of interest (D). The images were created with BioRender.com.

Metabolic rate. (A,D) Resting metabolic rate, (B,E) active metabolic rate, (C,F) the aerobic scope of 10–12 month old female (A–C) and male (D–F) zebrafish exposed to either 0, 1, or 10 ng venlafaxine at the 1–4 cell stage (n = 10–15 for respiration measurements). Different letters denote significant differences between groups. Individual data points and mean are shown for each graph (±S.E.M).

Behavioural assessment of juvenile fish. Behavioural responses of juvenile fish in lateral view (A,B), open field (C,D) or novel object assessments (E). Zebrafish were originally exposed to 0, 1, or 10 ng venlafaxine at the 1–4 cell stage. All assessments were recorded for 5 min. The novel object assessment occurred immediately after the open field assessment by the addition of an air stone directly into the middle of the arena (n = 9–13). Different letters denote significant differences between groups.

Behavioural assessment of adult fish. Total distance travelled by adult female (A–C) or male (D–F) zebrafish observed in a lateral view (A,D), open field (B,E), or novel object assessments (C,F). Zebrafish were originally exposed to either 0, 1, or 10 ng venlafaxine at the 1–4 cell stage. Zebrafish were recorded for 5 min immediately after placement into the arena. Total movement and the total distance away from the novel object are shown. Individual data points are shown with a mean ± SEM, with different letters used to denote significant differences between means.