Clove oil as an anaesthetic for common octopus (Octopus minor, Sasaki)

Abstract

We evaluated the anaesthetic effect of clove oil [2-methoxy-4-2-(2-propenyl)-phenol] on the common octopus (Octopus minor), in terms of the time required to become anaesthetized (‘anaesthetic time’) and recovery time. We used a factorial experimental design and administered clove oil at different temperatures (15, 20 and 25°C) and concentrations (50, 100, 150, 200, 250 and 300 mg L−1). We observed a significant (P<0.05) relationship between concentration and temperature, and each variable was effective (P<0.05). Anaesthetic time linearly decreased as the concentration and temperature increased. However, recovery time increased as the concentration increased and temperature decreased. There was no mortality. A concentration of 200 mg L−1 clove oil showed rapid anaesthetic and recovery times in the common octopus, indicating its suitability for this species.