Trabajo presentado en el 41st CIESM Congress, celebrado en Kiel del 12 al 16 de septiembre de 2016.A lead exposure experiment (7 days) was carried out to determine the biomarker responses in the gills and digestive gland of the clam Ruditapes philippinarum. Non significant response was found in acetylcholinesterase (AChE), catalase (CAT), superoxidase dismutase (SOD) in both gills and digestive gland. On the contrary, phase II antioxidant enzyme (glutathione S -transferase, GST) and antioxidant enzyme, glutathione peroxidase (GPx) have shown significant variation after 7 days of exposure to 100μg/L Pb. GST was induced significantly (p<0.05), contrariwise, GPx was significantly (p<0.05) inhibited in the digestive gland. The present investigation showed that 10 μg/L Pb did not show any toxic effect on the clam R. philippinarum, while, 100μg/L could engender some oxidative stress variations.N