Enhancing the Norm: Improving Cephalopod Welfare with Anesthetic Drugs
Lindsey Chan
Department of Biology
Faculty Supervisor: Robyn Crook
Cephalopods are remarkable invertebrates that have become popular comparative neuroscience models. While their popularity as lab models grows, understanding of their welfare continues to lag, especially in sedation and anesthesia. Although there is limited information on general or local anesthesia in cephalopods, there are no studies examining efficacy or safety of more modern, intramuscular-injected general anesthesic agents. Cuttlefish and squid have few known anesthetic drugs that efficiently block sensation to provide humane treatment throughout experimental procedures. Identifying an anesthetic drug or drug combination that has efficient nociception-blocking effects via intramuscular injection, combined with sedation or loss of consciousness, will improve the welfare of cephalopods in research. Here, we show the efficacy and overall effects of three drugs targeting different receptors. Alfaxalone had no anesthetic effect on cuttlefish or squid, but had an adverse effect on squid chromatophores. Dexmedetomidine and Ketamine had sedative effects in both species, but Dexmedetomidine had adverse effects, autophagy of arms, in cuttlefish. We found that, overall, Dexmedetomidine and Ketamine were moderately effective, however, none of the drugs produced full loss of consciousness. This study provides insight into receptors being targeted in cephalopods and shows that cephalopods in close taxonomic groups can have quite different responses to the same anesthetic agent.