Understanding Zebrafish predation on microplastics: The impact of multimodal sensory cues

The widespread contamination of aquatic ecosystems by microplastics (MPs) has raised urgent concerns about their ecotoxicological impacts on fish species. While previous studies have focused on direct MPs toxicity, the critical role of sensory cues in mediating fish-MPs interactions remains poorly understood. This investigation systematically examines how six potential infochemicals (three visual cues: rhodamine B, methylene blue, methyl green; three olfactory signals: dimethyl-beta-propiothetin, albumen powder, oxytetracycline) and their multimodal interactions influence polyethylene MPs (PE-MPs) predation behavior in zebrafish ( Danio rerio ). Olfactory infochemicals demonstrated significantly greater influence than visual cues in modulating zebrafish predation propensity toward PE-MPs. Zebrafish exhibited adaptive recognition capabilities, developing conditioned avoidance toward PE-MPs loaded with inedible infochemical signatures. However, multimodal sensory integration (tactile-visual-olfactory combinations) disrupted this discrimination capacity, increasing PE-MPs consumption through sensory conflict mechanisms. The surface of PE-MPs becomes rougher after passing through the zebrafish digestive tract, with the formation of 1–10 μm flaky or spherical MPs on the surface of PE-MPs. The findings emphasize the need to incorporate multisensory environmental parameters in aquatic risk assessments and inform the development of bioinspired MPs mitigation strategies.