Octopus Hypnosis: Non-Chemical Sedation in Studying Arm-Sucker Coordination

Abstract

ABSTRACTEffective methods of anesthesia for octopuses are important for physiological studies as well as for their welfare in scientific research. Neurophysiological studies of octopus usually use general anesthesia for invasive procedures like electrode implantation. However, commonly used forms of general anesthesia using ethanol, magnesium chloride, and similar agents have certain drawbacks in levels of stress, recovery, and tissue viability in octopuses much as in humans. We explore an old, rarely used method of octopus “hypnosis”, in which a still reaction is induced where communication between central and peripheral nervous systems is seemingly decreased. We modify the procedure for better handling, continuous respiration, and isolation of peripheral nervous system of the arm cords from the central nervous system (CNS), providing alternative to general anesthesia. Illustrative small studies of arm-sucker coordination and electrode placements are presented. The modified procedure limits negative side-effects, markedly reduces animals’ stress levels, and offers new avenues for octopus neurobehavioral research.