When it comes to lab animal welfare, rats and mice aren’t the only creatures of concern. In 2013, the European Union mandated that cephalopods—a group that includes octopuses and squid—be treated humanely when used for scientific research. In response, researchers have figured out how to anesthetize octopuses so the animals do not feel pain while being transported and handled during scientific experiments, for instance those examining their behavior, physiology, and neurobiology, as well as their use in aquaculture. In a study published online this month in the Journal of Aquatic Animal Health, researchers report immersing 10 specimens of the common octopus (Octopus vulgaris) in seawater with isoflurane, an anesthetic used in humans. They gradually increased the concentration of the substance from 0.5% to 2%. The investigators found that the animals lost the ability to respond to touch and their color paled, which means that their normal motor coordination of color regulation by the brain was lost, concluding that the animals were indeed anesthetized. The octopuses then recovered from the anesthesia within 40 to 60 minutes of being immersed in fresh seawater without the anesthetic, as they were able to respond to touch again and their color was back to normal. The researchers captured the anesthetization process on video, shown above.

(Video credit: Gianluca Polese)