In the current study, we report the thermal tolerance, standard metabolic rate (SMR) and preferred temperature of juvenile European sea bass (Dicentrarchus labrax) (1.2 +/- 0.4 g) acclimated at 15, 20, 25 and 30 degrees C for 30 days. Dynamic and static thermal tolerance zones of juvenile European sea bass are 861 degrees C-2 and 613 degrees C-2, respectively. The European sea bass is a fish species with low thermal resistance, with a resistance zone area of 162.5 degrees C-2. The SMR of the fish species at the above acclimation temperatures are 184, 255, 382 and 459 mg O-2 h(-1) kg(-1), respectively and are significantly different (P < 0.001, n = 10). The fact that SMR increases with rising temperatures and gradually decreases after 25 degrees C indicates that the preferred temperature ranges of juvenile European sea bass are between 25 and 30 degrees C. Our study shows that European sea bass has a low acclimatization capacity to survive in aquatic systems characterized by wide temperature fluctuations.