Dose Dependent Impact of Glyphosate on Haemocyte Morphology and Counts in Lamellidens marginalis

Lamellidens marginalis, a freshwater bivalve prevalent throughout the Indian subcontinent, plays a crucial role as a bioindicator in aquatic ecosystems. The hemolymph of bivalves is particularly valuable for evaluating toxicity levels in water bodies affected by chemical pollutants. This study examines the alterations in hemocytes and the cytotoxic effects on L. marginalis following sublethal exposure to glyphosate ammonium salt, a widely utilized broad-spectrum herbicide. Specimens were subjected to two concentrations (0.3 and 3 g/L) of glyphosate over periods of 3, 5, and 7 days. Hemolymph samples were assessed for total hemocyte count (THC), differential hemocyte count (DHC), and cellular morphology through Giemsa staining. The findings revealed a concentration- and time-dependent increase in THC, indicating a stress-related immunological response. DHC analysis showed a reduction in blast-like cells and hyalinocytes, alongside a significant increase in granulocytes, particularly at the higher concentration. Notable morphological changes, including vacuolization, nuclear fragmentation, membrane rupture, binucleation, and chromatin marginalization, were observed in hemocytes from the treated groups. Granulocytes emerged as the predominant and most morphologically altered cell type under stress, underscoring their essential role in immune defence and detoxification. These results suggest that glyphosate exposure can compromise the immune system of freshwater mussels, potentially increasing their susceptibility to pollution and disease, which may have broader implications for the health of freshwater ecosystems.