Benzo[a]pyrene as a behaviour altering compound in zebrafish

Abstract

Crude oil and other petroleum products contain the polycyclic aromatic hydrocarbon Benzo[a]Pyrene (BaP). This toxin affects the metabolism, physiology, and morphology of numerous species. However, the impact of BaP exposure on behaviour in aquatic organisms remains largely unexplored. Some studies suggest exposure may lead to increased boldness or aggression in marine fish. Shoal cohesion in zebrafish has been well explored and pharmacologically validated as a method of measuring boldness and anxiety-like behaviours, with increased boldness presenting as a more spread out shoal, with a greater inter-individual distance. To further explore the impact of BaP on behaviour in a freshwater species, we exposed shoals of 5 zebrafish (Danio rerio) to doses of 2.5, 25, and 250 µM of BaP and examined shoaling behaviour. Acute exposure (30 minutes) to BaP (250 µM) reduced shoal tightness, increasing the inter-individual distance. This suggests an increase in boldness due to acute BaP exposure, and an impact of BaP on social behaviour in zebrafish. This study confirms that acute exposure to BaP may directly impact behaviour, with the candidate mechanism to be explored in further studies.

Faculty Mentor: Trevor Hamilton

Department: Psychology