Juvenile and adult black sea bass (Centropristis striata L.) were exposed to various concentrations of four anaesthetics to determine practical dosages for handling as well as for procedures such as bleeding, ovarian biopsy or tag implantation. In experiment 1, juveniles exposed to either 2.0 mg L À 1 metomidate, 15 mg L À1 clove oil, 70 mg L À1 tricaine methanesulphonate (TMS) or 200 mg L À 1 2-phenoxyethanol (2-PE) reached stage II of anaesthesia in 3^5 min and could be handled for weighing and measuring. All ¢sh had completed recovery to stage III within 6 min. In experiment 2, the established concentrations of each anaesthetic were tested on juveniles to determine their ability to prevent a re£ex to a subcutaneous needle puncture. All of the ¢sh exposed to clove oil (20 mg L À 1 ) and 40% of the TMS-treated (70 mg L À 1 ) ¢sh reacted while none of the ¢sh anaesthetized in metomidate (2.0 mg L À1 ) or 2-PE (200 mg L À 1 ) responded to the needle puncture. In experiment 3, metomidate (5.0 mg L À1 ), clove oil (30 mg L À1 ) TMS (125 mg L À1 ) or 2-PE (300 mg L À 1 ) were all e¡ective for performing an ovarian biopsy or tag implantation on adults. In experiment 4, TMS (125 mg L À1 ) exacerbated the cortisol response to a short handling stressor during a 30 min exposure. Fish anaesthetized in 2-PE (300 mg L À 1 ), metomidate (5.0 mg L À 1 ) or clove oil (40 mg L À 1 ) had increased cortisol levels associated with the handling stressor but there were no further increases during the re-mainder of the experimental period. The results demonstrate that these anaesthetics are e¡ective for sedation and anaesthesia of black sea bass and that the best choice is dependant upon the procedures to be performed.