Not only do crabs and lobsters feel pain, they can remember it, and amend their behaviour as a result.
That's according to the latest research by scientists at Queen's University Belfast, who have been studying the reactions of hermit crabs to a series of electric shocks.
The finding overturns conventional wisdom: which holds that crustaceans like crabs, shrimps and lobsters can't feel pain because they don't have the highly developed central nervous system necessary to process the information.
It was known that crabs could detect harmful environmental stimuli and move away from the source, but that was not thought to involve the inner "feeling" of unpleasantness we associate with pain.
Hermit crabs have no shell of their own, but make their homes in abandoned mollusc shells. Professor Robert Elwood attached wires to a series of shells, delivering small electric shocks to the hermit crabs inside.
The only crabs to get out of their shells were those that had received shocks, indicating that the experience was unpleasant. But crabs were also more likely to abandon inferior shells, leading Prof Elwood to conclude that neuronal processing was occurring rather than a simple reflex response.
When offered a new shell some time later, shocked crabs were also much more likely to change - indicating that they retained some memory of the experience.
It's bad news for seafood lovers, who may have to think again about boiling crabs and lobsters alive.