Consistent exposure to microplastics induces age-specific physiological and biochemical changes in a marine mysid

In this study, a marine mysid, Neomysis awatschensis, was exposed to 1 × 10³-5 × 10⁵ particles mL^-1 of polystyrene microbeads (1 and 10 μm). Exposure to microplastics (MPs) resulted in ingestion and egestion in feces. MPs exposure during the early stage resulted in mortality and oxidative stress, while more mature stages were increasingly tolerant to MPs. Feeding rates were inhibited by MPs, and age-specific oxidative stress was observed. Growth parameters were significantly affected by MPs with lower 20-hydroxyecdysone (20E) concentrations and longer intermolt durations. The number of hatched juveniles from females that were exposed to MPs was significantly lower than the control treatment, but no significant differences were observed between survival rates of newly hatched juveniles in the different treatments. Our results suggest that the detrimental effects of prolonged exposure to MPs could be age- and size-specific and harmful for the maintenance of mysid populations.