Are Microplastics Impairing Marine Fish Larviculture?—Preliminary Results with Argyrosomus regius

The presence of small-sized (<300 µm) microplastics (MPs) in aquaculture facilities may threaten finfish hatchery, as their (in)voluntary ingestion by fish larvae compromise nutritional requirements during early ontogeny, and consequently larval health performance. Thus, we addressed the short-term effects (7 h) polyethylene (0.1, 1.0, 10 mg/L, PE-MPs) meagre Argyrosomus regius (15 dph) presence/absence food. Larval feeding behavior, oxidative stress status, neurotoxicity, metabolic were evaluated. Results showed that ingested PE-MPs regardless concentration, decreasing food (Artemia metanauplii). compromised activity at highest concentration. Under starvation, exposed activated antioxidant defenses increasing total glutathione levels inhibiting catalase activity, which seemed efficient to prevent damage. Such also presented increased energy consumption potentially related damage prevention decreased neurotransmission. Biochemical responses fed a similar trend, except for LPO, remained unaffected, 0.1 mg/PE-MPs/L. Our results suggest MPs hatcheries requirements, but considerably higher than those reported marine environments. Nevertheless, cumulative adverse due lower concentrations occur.