Polyethylene Microplastics Affected Survival Rate, Food Intake and Altered Oxidative Stress Parameters in Freshwater Snail Indoplanorbis exustus.

Abstract

Microplastics have a negative impact on aquatic ecosystems. Gastropod mollusks serve as bioindicators and are good model systems for ecotoxicological studies. To assess oxidative damage, we exposed the ram's horn snail, Indoplanorbis exustus, to various concentrations of low-density polyethylene microplastics (size range 8-100µm). The main objectives were microplastics preparation, characterization, and examination of their effect on the essential organs of I. exustus. Scanning electron microscopy, fourier transform infrared spectroscopy and x-ray diffraction techniques confirmed the polymer type of laboratory prepared polyethylene microplastics. The LC50 value of microplastics for snails was calculated to be 872mg/L after 96h of exposure. We observed a significant elevation in superoxide dismutase, catalase and lipid peroxidation levels with increasing concentrations of microplastics. Microplastics exposure also affected protein content, total food intake and total weights. Moreover, snails failed to recover post-treatment. Snails collected from contaminated source of microplastics served as positive control for the study. Hence, we can conclude that microplastics cause overall impairment in the physiological parameters and show adverse effects on the freshwater snail, I. exustus.