Exploring the limits to our understanding of whether fish feel pain

 In the United Kingdom, the Animals (Scientific Procedures) Act 1986 (HMSO, 1986) regulates experimental work on vertebrate animals. The European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes (Council of Europe, 1986) covers the same ground. Both the British law and the EU Convention use a closely similar set of criteria to judge the status of a scientific procedure. The British law states that “a regulated procedure on a protected animal under the 1986 Act is one that may have the effect of causing that animal pain, suffering, distress or lasting harm.” The same words are used in the EU Convention to define a procedure as being regulated. Recently in the UK the Animal Welfare (Sentience) Act 2022 (HMSO, 2022) takes the topic even further in that it is “an Act to make provision for an Animal Sentience Committee with functions relating to the effect of government policy on the welfare of animals as sentient beings.” It goes on to say that “in this Act ‘animal’” means (a) any vertebrate other than Homo sapiens, (b) any cephalopod mollusc and (c) any decapod crustacean.