Pain and Suffering in Invertebrates: An Insight on Cephalopods

Invertebrates are a broad group of animals that includes more than 90% of the estimated 10 million species in the world. Some species are abundantly used by man in scientific research and for human consumption. However, the current legislation is still very lacking about the protection toward conditions of pain, suffering, distress or lasting harm that these animals may suffer as a result of experimental practices, fishing and cooking. The purpose of this paper is to summarize what has already been stated by other Authors regarding the possibility that invertebrates (with a specific emphasis on cephalopods) can experience pain and suffering. The results of studies that show the existence, in these animals, of a number of elements that can be associated with the ability to feel pain and not only nociception are highlighted. Objective indicators (such as changes in physiological parameters) and behavioral attitudes of cephalopods that might be related to pain will be addressed as well.