Impact of perfluorooctane sulfonic acid (PFOS) and environmental microplastics on Mytilus galloprovincialis larval development: Cross-disciplinary approach

Understanding the impacts of environmental microplastics (EMPs) and perfluorooctane sulfonic acid (PFOS) on marine species development is critical due to their widespread and persistent presence in aquatic environments. This study investigates, for the first time, the combined effects of EMPs and PFOS on the early development of Mytilus galloprovincialis larvae, focusing on larval quality, shell biomineralization, and apoptosis, and explores the molecular mechanisms underlying these impacts. Through dose-response analysis, effective concentrations of PFOS for inducing larval alterations were determined (EC25: 3.9 μg/L; EC50: 20.45 μg/L). Morphological assessments revealed significant developmental anomalies, including arrested growth and shell deformities, with the most severe effects observed under co-exposure to EMPs and 20.45 μg/L PFOS. Immunofluorescence and molecular analyses demonstrated disrupted tubulin expression, a key cytoskeletal protein, and altered tubulin and Histidine-rich glycoprotein (HRG) transcript levels, both essential for proper shell formation. Additionally, co-exposure triggered DNA damage and developmental arrest through apoptosis activation. These findings underscore the detrimental effects of EMPs and PFOS on marine bivalve larvae, posing risks to species survival and ecosystem stability. Addressing these pollutants is essential to safeguarding marine biodiversity and maintaining ecological balance.