Behavioral alterations produced by exposure to the antidepressant fluoxetine in two fish species of the family Poeciliidae

KOLESNIK, M.; LO NOSTRO, F.; MEIJIDE, F.

Montevideo

Congreso; XV Congreso SETAC Latinoamérica; 2023

SETAC Latinoamérica

Chemical pollution from pharmaceuticals is increasingly recognized as a major threat for aquatic wildlife. Among the wide variety of pharmaceuticals, fluoxetine (FLX) is one of the most widely prescribed antidepressants, often detected in aquatic systems that receive sewage and pharmaceutical effluents. Since FLX is designed to modulate human behavior and its action pathways are conserved in vertebrates, this compound could affect the behavior of non-target species such as fishes. In this regard, behavior is an ecologically relevant indicator of exposure to neuroactive compounds as it can directly affect the fitness and survival of organisms. In turn, behavioral biomarkers are gaining increasing interest as an early warning system in ecotoxicological studies. In this study, female Cnesterodon decemmaculatus and Gambusia holbrooki (Teleostei, Poeciliidae) were exposed to nominal concentrations of 0 (control), 1, 5, 25, and 50 μg/L FLX for 14 days, under a semi-static design with daily renewal of test solutions (n=5 per aquarium, in duplicate). Following exposure, aggressive interactions between individuals in each aquarium were recorded by video for 10 min, before and after being fed Artemia sp. nauplii. From the video records, the latency to emergence of aggression, as well as the number and duration of aggressive interactions in which each individual participated, were quantified. Next, each fish was transferred to an individual aquarium, and after 90 min, swimming activity was recorded for 10 min. Videos were analyzed using Ethovision software to quantify locomotion parameters (distance travelled, average speed, time in motion, static time, time in each third of the water column). The results showed differential effects of FLX in both species. In C. decemmaculatus, exposure to higher concentrations of FLX resulted in an increase in aggressive interactions between conspecifics in the presence of food, as well as an alteration of swimming activity. In G. holbrooki, a marked attenuation of swimming activity was evident with increasing FLX concentrations, whereas the effects on aggression were less evident. For both responses, the effects were significant at concentrations higher than those of environmental relevance. The results of this study contribute to the assessment of the impact of pharmaceuticals on fish fauna.