Potential Toxic Effects of Environmental Plastic Litters on Wharf Roach (Ligia exotica): Two Omics Approaches

Abstract

This is first report to evaluate the toxic effects on wharf roach (Ligia exotica) exposed to environmental plastic litter: L. exotica, is an important ecological position as plastic detritus consumer. An experimental survey was conducted on May–June 2019 at two nearshore areas of South Korea including Maemul-do [microplastic (MP) contaminated site] and Nae- do [MP uncontaminated site]. The average MP abundances (>20 μm) was higher in L. exotica from Maemul-do (107.83 particles/individual) than those of Nae-do (1.00 particles/individual). Composition of MPs was dominated by the expanded polystyrene (EPS) in L. exotica from Maemul-do (93%). The comparative results of the transcriptomic analysis revealed significantly altered expression of genes associated with metabolic process, mitotic cell cycle regulation and immune system (cutoff: q< 0.05) in L. exotica sampled at Maemul-do. Four neurosteroids were also detected in brain, concentration of cortisol and progesterone significantly variated in L. exotica sampled at Maemul-do. Our findings highlight the importance of management of MP pollution and toxic effects of translocated MP using the bio- indicator species.