Effects of Polystyrene Microplastics on Sound Production of Medaka Fish (Oryzias latipes)

Microplastic pollution is increasingly recognized as a major global environmental issue.Studies have shown that microplastics (MPs) can affect various aspects of fish biology, including physiology, neurotoxicity, and behavior.To explore the potential of Japanese medaka (Oryzias latipes) as an indicator of MP pollution, we evaluated the effects of polystyrene microplastic (PS-MP) exposure on sound production.Test fish were assigned to one of three conditions: control, low concentration PS-MP exposure (0.01 mg/L), and high concentration PS-MP exposure (0.1 mg/L).Each fish underwent a sound production test on days 4 and 7. Exposure to high concentrations of PS-MP significantly lengthened the average sound inter-pulse interval, along with notable changes in other vocal trait parameters showing a reduced sound production activity upon exposure.These findings suggest that Japanese medaka sound production could serve as an effective biomonitoring tool for abnormal water conditions, including for detection of PS-MP and possibly other pollutants.