Effects of the fungicide carbendazim on the behaviour of the zebrafish Danio rerio (Cypriniformes, Cyprinidae)

One of the commonest pesticides used in agriculture is the fungicide carbendazim, which can cause deleterious effects on the physiology and behaviour of acutely and chronically exposed animals. However, few studies have evaluated the effects of carbendazim on fish behaviour and our main objective was to evaluate behavioural changes on adult zebrafish (Danio rerio) exposed to this fungicide. We studied 177 fishes, divided into control groups (not exposed) and treatment groups, exposed to a concentration of 120 mu g/L for 7, 14, 21 and 28. Behavioural data were collected using the scan sampling, with instantaneous recording every 30 s. We evaluated and compared fish behaviours and aquarium occupancy between treatments and controls using Generalized Linear Mixed Models. The results indicate that carbendazim initially elicited slow swimming and later fast swimming, decreased aggressiveness, and caused behavioural changes indicative of distress, like abnormal swimming and the gulping of air in water surface. In the wild, this behavioural change can result in an increased predation risk and consequent decrease or extinction of populations, revealing important ecological issues for animal communities living in polluted water bodies.