Crustaceans and molluscs are increasingly used in research as simpler model organisms, but their welfare needs are poorly understood and rarely considered.
Aquatic invertebrate welfare in research is at an early stage of development analogous to where fish welfare was two decades ago. As evidence for crustacean nociception and stress responses has strengthened, regulatory frameworks have begun to respond. The UK inclusion of decapod crustaceans in welfare legislation represents a precautionary response to this evidence. Killing methods — boiling, spiking, or CO2 — deserve welfare assessment that they currently rarely receive.