The efficacy of three anaesthetics was investigated in adult Blue-spot gobies (Pseudogobius sp.). Induction, recovery, and 24- and 48-hour survival was determined for clove oil: 50 mg/L, 75 mg/L, 100 mg/L, tricaine and benzocaine: 200 mg/L. All of these were sufficient to induce complete anaesthesia within 15 minutes for all individuals. Post-anaesthesia, most individuals (94%) reached full recovery within 25 minutes. No mortality was observed at 48 hours regardless of anaesthetic used. As predicted, an increase in the concentration of clove oil resulted in a decreased time to complete anaesthesia, however, this did not affect recovery time.

The clove oil concentrations found effective for anaesthesia overlap with those reported for other Australian freshwater and estuarine fish species. These results demonstrate that the anaesthetics investigated are appropriate for sedation of a small, native fishes, with clove oil being the preferred choice, as it is the cheapest, safest for human handling and most environmentally friendly. Ultimately, the choice of anaesthetic is dependent on the sensitivity of the fish species, as well as the type of procedures to be completed. As part of fish research, it is critical to establish reliable anaesthesia methods that focus on the welfare of the study species.