The ethics of shellfish consumption is an ongoing conversation in the omnivore community. Meat and fish are (for the most part) killed quickly to minimize suffering. However, lobsters and crabs are often cooked live, thrown twitching into boiling water.
A popular argument justifying this preparation is that invertebrate like lobsters and crabs lack a central nervous system complex enough to register pain. But studies have never been conclusive, and the story rears its head every few years; most notably, in an essay in a non-fiction collection called Consider the Lobster by the late David Foster Wallace.
This recent article from the Washington Post and accompanying video raises the issue once again of whether lobsters feel pain. It tells the story of Rick Stein, a seafood-focused chef and cookbook author in England, who posed the question to his colleague, Robert Elwood, in an Irish Pub. Elwood is a professor of biology who has been studying crabs and prawns for 30 years, but he’d never questioned whether his test subject can feel what we understand as pain.
The crucial distinction is between pain and reflex. Invertebrate respond to contact we might consider painful, but it doesn’t definitively mean they register pain. It could be as simple as the response we experience when a doctor taps your knee with a reflex hammer, which would support the “no pain” theory.
But Elwood ran several tests introducing painful stimuli to prawn and crabs, and discovered a surprising response. The invertebrate animal would react to being shocked—or brushed with acid—by rubbing the afflicted areas, much like a human would rub a bruise. Pain can also affect behavior, dissuading shore crabs from nesting in natural habitats if they are exposed to shocks in said habitat. This action suggests that their behavior is triggered by the stimulus—a negative response implying the sensation of pain.
The results are far from definitive. It’s impossible to measure something as subjective and personal as pain, particularly in organisms as alien to us as invertebrates. So feel free to drown any ethical quandaries this conversation may stir in a ramekin of drawn butter.