Beteendeförändringar till följd av exponering av läkemedlet Oxazepam : Förändringar i social tendens och aktivitet hos dvärgtandkarp (Heterandria formosa) och guppy (Poecilia reticulate)

The aquatic environment is more or less constantly exposed to different types of pharmaceutical pollutants entering via treated waste water effluents. Benzodiazepines constitute one of many common pharmaceutical contaminants, which have been shown to impact fish behaviour in polluted freshwaters. The aim of this study was to assess whether one benzodiazepine (Oxazepam) affects the behaviour (activity and sociability) of guppies and least killifish. 50 fish of each species were studied in behaviour assays measuring the activity and sociability, where each individual was placed in separate aquariums and filmed in a special arena. One half of the individuals were then exposed to 10 μg/l Oxazepam in their respective tank for 7 days, after which the filming procedure were repeated for all fishes. The results show that least killifish significantly change their sociability by becoming less social after exposure to Oxazepam. However, their activity were not significantly affected. The result from guppies suggested a reduced sociability after exposure. Interpretation of the result were complicated by effects on the control group were guppies experienced a significantly reduced sociability during the treatment. This might be an effect of changes in habitat (lack of food, stress and environment) and/or an effect of Oxazepam. The results in the study show that Oxazepam reduces the sociability of least killifish and guppies.