Muscular cholinesterases and hepatic biomarkers of xenobiotic metabolism in Mediterranean fish: Relationship with ecological variables

Abstract

Sixteen fish species of teleosts and two elasmobranchs were selected for the characterization and determination of cholinesterase activities and lipid peroxidation levels in muscle and the determination of xenobiotic metabolism enzymes in liver, all biomarkers used in pollution monitoring. The sampling took place seasonally during 2007 in the NW Mediterranean. The hepatic enzymes considered were the activities of catalase, glutathione reductase, ethoxyresorufin O-deethylase, carboxylesterase and glutathione S-transferase. As ecological markers we considered trophic resources, swimming capability, stomach fullness and trophic level. Significant differences were found among species and, in general enzymatic activities were much higher in teleosts than in the elasmobranchs, and in perciforms than in gadiforms. Seasonal rather than site differences were seen in accordance to a small pollution gradient. A multivariate canonical correspondence analysis revealed that cholinesterases were positively related to suprabenthos feeders, whereas the ecological variables in fish from the shelf had a prominent role determining hepatic biomarkers expression