Variability in microplastic color preference and intake among selected marine and freshwater fish and crustaceans

Abstract Plastic pollution is considered a pervasive global environmental challenge. Colored microplastics are prevalent in aquatic environments and the gastrointestinal tracts of wild-captured fish and crustaceans. Fish are thought to employ color vision to detect microplastics, prompting our investigation into microplastic ingestion patterns in three marine fish species, Chrysiptera cyanea , Hypoatherina tsurugae, and Plotosus japonicus , and three freshwater fish species, Rhodeus ocellatus , Pseudorasbora parva , and Misgurnus anguillicaudatus . Microplastics in red, blue, yellow, green, and gray were introduced to these species, and their ingestion was observed over a 4 h period under light conditions. Additionally, as crustaceans play an important role in connecting producers (phytoplankton) and consumers (fish) in natural ecosystems, we assessed a freshwater crustacean, Neocaridina denticulata . The crustacean did not ingest microplastics, and only 14% of P. parva individuals ingested microplastics (a proportion lower than that observed in the other fish species). Notably, C. cyanea , P. japonicus , and R. ocellatus exhibited color preferences in microplastic ingestion, with C. cyanea favoring red, P. japonicus preferring blue and gray, and R. ocellatus favoring red and yellow. Conversely, H. tsurugae , P. parva, and M. anguillicaudatus did not exhibit such color preferences . These findings suggest that certain fish use color vision to recognize and selectively ingest microplastics, with color preference being species-specific. Overall, this study provides new insights into microplastic ingestion by fish, potentially informing future toxicological assessments of microplastics in marine and freshwater fish and crustaceans intendan consumption.