Unveiling the effects of polyethylene microplastic on the physiological responses across different size classes of...

Microplastics (MPs) have wreaked havoc on aquatic ecosystems due to their heightened accumulation potential. Polyethylene (PE) is the most dominant MP polymer contaminating several estuaries globally. This study aims to evaluate the acute exposure of MPs on two size classes of mangrove horn snail, Telescopium telescopium. Small (50-70 mm) and large (90-120 mm) sized organisms were exposed to polyethylene microplastics (PE-MPs) of diameter 34-50 microm, for a period of 21 days. PE-MP toxicity was assessed by monitoring the physiological energetics and oxidative stress biomarker responses at three environmentally relevant concentrations (2, 20, 200 microg L^-1). Negative Scope for Growth was observed in both size classes at medium and high concentrations. Moreover, PE-MPs significantly induced oxidative damage at 20 and 200 microg L^-1 concentrations. Noticeable DNA damage was observed across all PE-MP concentrations. Small sized gastropods were more vulnerable to MP toxicity than their larger counterparts. Integrated Biomarker Response indicated Superoxide Dismutase as the most responsive biomarker for assessing the toxicological effects of MPs. Present study provides new insights on the potential impacts of PE-MPs on different size classes of T. telescopium from Sundarbans Estuarine System.