Scientific evidence on the sentience and pain capacity of aquatic invertebrates including crabs, lobsters, and mantis shrimp is accumulating rapidly, with important implications for welfare standards.
Aquatic invertebrate welfare represents the leading edge of applied sentience science. The evidence that crabs, lobsters, and related species can suffer is now sufficient to have driven legislative protection in the UK -- a significant regulatory milestone. Yet globally, billions of decapod crustaceans are boiled alive annually without any welfare consideration. The scale of the welfare harm, if the sentience evidence is correct, is enormous. Humane killing methods for crustaceans exist -- electrical stunning, mechanical piercing of the nervous system -- and are used in some high-welfare contexts. Consumer choices and retailer standards are the primary levers for change ahead of regulatory requirements in most countries.