Efeitos da exposição a estímulo sonoro no comportamento do peixe donzela (Stegastes fuscus)

Abstract

Anthropogenic noise levels are increasing globally and affect several habitats. Studies point out the deleterious effects of acoustic pollution on the local fauna in marine environments. However, little is known about how noise generated outside the aquatic environment may affect fish behavior and cognition in coastal areas. This study aimed to evaluate the effects of sound stimuli exposure on memory retention and anxious-like behavior in dusky damselfish Stegastes fuscus, an endemic species of the Brazilian reefs. The animals were exposed to two daily sessions of music at intensities of 90-100 dBA (n=11) or 60-70 dBA (n=11), and the control group was kept at 42-46 dBA (no music; n = 10) for 5 days. Then, fish were tested for memory of aversive conditioning (trained before the sound stimulus to avoid an aversive electroshock stimulus applied to the black and white shuttle box tank's black side) and tested for the novel tank paradigm. Behavior evaluated were latency to enter and time inside the tank's black side (to access memory), locomotion (speed and distance traveled), freezing, time in each area of the tank, and distance from the bottom (to access anxiety responses) areas of the tank and how much of the bottom to access the parameters. The animals exposed to the sound stimulus, at both intensities, spent more time on the black side of the tank, where they received the electroshock, indicating decreased memory of the aversive event. In the novel tank, the animals exposed to noise spent more time still and decreased the distance from the bottom of the tank, indicating increased anxiety-like behavior. These results suggest that anthropogenic noise applied here through high-intensity music can lead to increased anxiety and decreased memory retention in S. fuscus, suggesting the deleterious potential of noise for reef species.