Variability of basal hepatic ethoxyresorufin-o-deethylase activity in bream ( Abramis brama L.)

The variability of hepatic EROD activity in bream depending on fish size, age, and reproductive activity has been analyzed. The relations between EROD activity and fish size and age were not recorded. Enzyme activity was elevated in the pre-spawning period and decreased at the time of spawning. The most pronounced sex differences were observed at the pre-spawning period. The variability of hepatic EROD activity in bream should be taken into account in designing and conducting biomonitoring studies.