Microplastic toxicity in shrimp: From mechanistic pathways to ecological implications

Microplastic pollution has emerged as a pervasive and persistent stressor in aquatic environments, raising urgent concerns for ecosystem integrity and food safety. Given the ecological and commercial importance of shrimp as both key benthic organisms and human food sources, this review systematically synthesizes and critically evaluates 94 studies (2016-2025) addressing the toxicity and bioaccumulation of microplastics in shrimp species. We identify mechanistic pathways linking particle characteristics (size, shape, polymer type, and surface functionalization) to biological responses at molecular, cellular, organ, and organism levels. Lethal and sublethal outcomes are strongly dependent on microplastic properties, inducing organ-specific injuries to the hepatopancreas, gills, muscle, gut, and gonads. Multi-omics and biochemical analyses reveal oxidative stress, immune dysfunction, apoptosis, metabolic disturbance, and neurotoxicity as core mechanistic cascades underlying growth inhibition, with potential links to reproductive impairment. Although most studies were laboratory-based, the convergence of evidence underscores that current exposure levels pose tangible ecological risks. These findings highlight shrimp as effective bioindicators for assessing microplastic pollution in aquatic systems. By bridging mechanistic evidence with ecological implications, this review provides a framework for risk assessment and informs management strategies to mitigate microplastic impacts on aquatic ecosystems and seafood safety.