Animal welfare legislation in Western countries follows similar principles, differing mainly in complexity and scope. The legislation basically protects vertebrates, since it considers them capable of having subjective experiences such as pain and suffering. Studies utilizing physiological, neuroanatomical and behavioral parameters indicate that invertebrates like cephalopods and decapods are sentient beings, and thus eligible for legal protection in some countries. We suggest an approach to sentience that uses basic requirements, not restricted to vertebrates. Social and economic factors as well as species seem to influence the non-attribution of sentience to invertebrates. Thus, it is evident the need for a bioethical analysis to substantiate their inclusion in the legislation. The "benefit of doubt" is supported by the arguments of "evolutionary continuity" and "principle of precaution". In the mean time we suggest that the use of invertebrates for scientific purposes should be cautious and sensible.
Invertebrates; Legislation; Sentience; Animal experimentation; Specism