Beyond the glass: testing visitor effects on the behavior of teleost fish in public aquaria

Visitor density and direct sonic solicitations significantly drive behavioral changes in 13 teleost species, with marked sensitivity in five species and no obvious changes in others.

• Why it matters: Animal welfare in public aquariums depends on managing the visitor effect, which is well documented in mammals but largely unexamined in teleost fish despite evidence of human sensitivity in nature.
• What they did: The study tested behavioral responses across varying visitor density, direct human solicitations (e.g., knocking on glass), and ambient noise, using multivariate analysis and acoustic analysis of sound amplitude.
• The result: Global visitor density correlated with increased sound amplitude in the 100 Hz to 400 Hz range, and visitor-induced noise appears distinct from technical background noise, supporting species-specific welfare monitoring.