Fairy shrimp Branchinella kugenumaensis displays sensitivity to microplastic exposure.

The increasing global concern regarding plastic pollution has prompted the research into the consequences of microplastics (MPs) on aquatic ecosystems. Fairy shrimp Branchinella kugenumaensis are freshwater planktonic organisms that have existed for 250 million years. This study aimed to uncover the harmful effects of MPs, with a particular focus on their size variations (0.1, 1, and 5 µm), on the fairy shrimp. We focused on how MPs could significantly affect the survival and growth of fairy shrimp. Notably, larger MPs, especially those measuring 5 µm, caused higher mortality rates and hindered the growth compared to smaller ones. The impact of MPs continued even subsequent to depuration in clean water. The accumulation of MPs within the intestines of fairy shrimp resulted in intestinal blockages, disrupted excretory functions, and harmed intestinal epithelial cells. Examinations at the histological, cellular, and molecular levels showed that exposure to MPs triggered necroptosis in intestinal cells, accompanied by alterations in pathways related to transcription, translation, digestion, energy metabolism, and neurological functions. Furthermore, the effects of MPs on gene expression and pathways varied based on particle size, with larger MPs having a more significant effect and causing a strong response in xenobiotic biodegradation and metabolism pathways. We suggest that the increasing severity of MPs pollution could pose a significant threat to the survival of fairy shrimp. This study provided vital insights into the complex relationship between microplastics and aquatic organisms, and highlighted the urgent need to address the potential devastating impact of plastic pollution on freshwater ecosystems. Additionally, due to their rapid growth, strong reproductive capacity, sensitivity, and ease of cultivation, fairy shrimp hold the potential candidate to serve as a model organism for studying the effects of MPs and other pollutants on freshwater ecosystems. [ABSTRACT FROM AUTHOR]