Effects of environmental microplastics on Porcellana Platycheles (Decapoda, Anomura, Porcellanidae), a marine filter-feeder crustacean

Abstract Assessment of microplastic pollution is a societal concern with negative impacts on fauna and flora. An omnipresence of these pollutants in aquatic, atmospheric, and terrestrial ecosystems was indicated. In a marine environment, the microplastic accumulation and effects were identified in many organisms (annelids, bivalves, crustaceans, fishes, mammals…). Unfortunately, many microplastic (MP) toxicity experiments used commercial particles (mainly polyethylene or polystyrene), which do not illustrate the diversity of environmental MP. We evaluated the effects of environmental MP on Porcellana platycheles , which is a European singular crustacean (Anomura) being a filter-feeder organism. We carried out direct exposures for 5 and 10 days at two environmental concentrations [10°µg/L (low) and 100°µg/L (high)]. The biomarkers analysed were the antioxidative response level, acetylcholinesterase activity, lipid peroxidation, and energy reserves. Our study revealed a high acetylcholinesterase inhibition reflecting neurotoxicity, and modulation of antioxidative responses illustrated successively by an increase of enzymatic activities at 10°µg/L after 5 days, and a decrease after 10 days of exposures. Inhibition of antioxidative activities at 100°µg/L was also noted. We hypothesised that this “inverse U-shaped” enzymatic activity could be due to 1/ the presence of endocrine disruptors associated with MPs, such as Dibutyl phthalate found in high concentration (126°µg/g) in our MP samples and/or 2/ collapse of the endogenous antioxidative enzymes. In parallel, a depression of glycogen was demonstrated during the experiments indicating an energy investment in maintaining homeostasis. Thus, Porcellana platycheles possesses all the criteria to be considered as a potential sentinel species to detect the microplastic effects.