Increasing marine microplastic pollution has detrimentally impacted organismal physiology and ecosystem functioning. While previous studies document negative effects of microplastics on coral reef animals, the potential responses of organisms such as Large Benthic Foraminifera (LBF) are largely unknown. Here, we document the impact of microplastics on heterotrophic feeding behavior of LBF. Specimens of Amphistegina gibbosa were incubated in three experimental treatments: (1) Artemia sp. nauplii only; (2) pristine microplastic particles only; (3) choice of nauplii...