Transfer of microplastics from a freshwater mussel (Megalonaias nervosa) to a snail (Planorbella pilbsryi) raw data

Microplastics (<5 mm) are pervasive freshwater contaminants whose physical characteristics influence ingestion patterns and trophic availability in aquatic organisms. This study examined how microplastic shape affects egestion by the freshwater mussel Megalonaias nervosa, and whether mussel waste-coated microplastics alter bioavailability to the freshwater snail Planorbella pilbsryi compared to pristine particles.

Mussels were individually exposed to 61 µm red polyester microfibres, 79 µm blue polyester microfibres or 6 µm red polystyrene microspheres. Microplastic-enriched mussel waste was subsequently used in 28-day P. pilbsryi exposures alongside pristine microplastics to assess ingestion, survival and reproductive endpoints. Particle shape and size significantly influenced mussel egestion, with microspheres more abundant in waste than either microfibre type.