Clove oil has become a popular fish anaesthetic for invasive fisheries research procedures, but
few studies have examined the use of low concentrations of clove oil to achieve sedation for
aquaculture procedures such as fish handling and transport. In this study, we used largemouth bass
as a model species to examine the behavioral and physiological responses of fish to a gradation of
clove oil concentrations (0 to 20 mg l1) while exposed to truck transport. Concentrations of clove
oil ranging from ~5 to 9 mg l1 elicited a sedative effect resulting in loss of reactivity and reduced
cardiac output while maintaining equilibrium. Fish sedated by 5 to 9 mg l1 clove oil achieved that
level of anaesthetization rapidly and recovered behaviorally more quickly than at higher
concentrations. During transportation, videography revealed that fish in deep sedation (stage 2