Biochemical aspects of susceptibility to stressors in two small cyprinids Squalius laietanus and Barbus meridionalis from the NW Mediterranean

Specimens of two endemic cyprinids, Squalius laietanus (Catalan chub) and Barbus meridionalis (Mediterranean barbel), were sampled from a reference site in small stream the Ripoll River (NW Mediterranean) outside their reproductive season. Biomarkers involved xenobiotic-mediated responses individually contrasted fish both species 17 perfluoroalkyl substances (PFASs) analysed muscle to reveal bioaccumulation trends. The parameters muscle: cholinesterases, metabolic lactate dehydrogenase (LDH) citrate synthase (CS); liver: cytochrome P450 dependent activities (EROD BFCOD), carboxylesterase (CE), glutathione S-transferase (GST), reductase (GR), peroxidase (GPX) catalase (CAT). All markers are considered adaptive defence mechanism face stress. Sensitivity model pesticide: dichlorvos was also vitro muscular acetylcholinesterase (AChE) hepatic CE sensitivity neurotoxic chemicals. Enzymatic related protective mechanisms such as butyrylcholinesterase (BuChE), CAT higher chub whereas antioxidant defences GR GPX barbel. Aerobic CS barbel while anaerobic LDH so chub. EROD activity did not differ between but BFCOD Levels PFAS likely due its benthic habitat. tests revealed AChE (lower IC50) which probably compensated by catalytic efficiency CE. these former biochemical particularities discussed terms ecological performance front anthropogenic stressors.