Surprised? New study shows crabs, lobsters feel pain

A new study published in the journal Biology, provides strong evidence that crustaceans such as crabs and shrimp experience pain, raising ethical concerns over their treatment in culinary practices. The research was conducted by scientists at the University of Gothenburg.

The researchers, led by PhD candidate Eleftherios Kasiouras and Dr. Lynne Sneddon, conducted experiments on shore crabs (Carcinus maenas) to measure their responses to harmful stimuli. Using electrophysiological equipment, they detected nerve-cell reactions in the crabs' brains during painful stimuli. They attached electrodes to the crabs' central nervous systems to record brain activity in response to various stimuli, including mechanical pressure and chemical irritants.

"We could see that the crab has some kind of pain receptors in its soft tissues because we recorded an increase in brain activity when we applied a potentially painful chemical, a form of vinegar, to the crab's soft tissues," Kasiouras explained, according to Phys.org. "The same happened when we applied external pressure to several of the crab's body parts," he added.

The study showed that the crabs possess nociceptors that detect damaging stimuli and send signals to the central nervous system, indicating that they feel pain. Furthermore, the electrical activity from the mechanical stimulus was coded in a different pattern than from the chemical stimulus, allowing researchers to tell from the crab's brain activity whether it was processing chemical or mechanical stimuli.

Kasiouras stated, "We can assume that shrimp, crayfish, and lobsters can also send external signals about painful stimuli to their brain, which will process this information."

"It is a given that all animals need some kind of pain system to cope by avoiding danger. I don't think we need to test all species of crustaceans, as they have a similar structure and therefore similar nervous systems," he added.

For many years, boiling lobsters and crabs alive has been a common method of killing them in kitchens. It was suggested that the way lobsters respond was simply due to reflexes, but the latest study provides evidence that they experience and react to pain.

In light of these revelations, scientists are calling for more humane culinary methods to prepare shellfish. "We believe that the boiling of crustaceans alive should be banned and cooking techniques such as electro stunning should be applied the moment that the crustaceans are caught," Kasiouras told the Daily Mail.

"If they're suffering, we need to find ways to minimise their pain," he added.

"We need to find less painful ways to kill shellfish if we are to continue eating them. Because now we have scientific evidence that they both experience and react to pain," Sneddon said.

Currently, crustaceans do not receive protection under European Union legislation, despite the UK recognizing them as sentient animals. This means there are no guidelines on how to humanely handle or kill crustaceans, whether in labs or kitchens.

Animal welfare organizations are also highlighting the need for change. Crustacean Compassion pointed out that there are several unethical ways of killing decapods, including boiling, dismemberment, electrical killing, splitting, CO2 gassing, freshwater drowning, and both dry and wet chilling, according to the New York Post.

Farmed crabs are often kept together in small tanks, which Kasiouras described as "really miserable," according to Sky News. 

This article was written in collaboration with generative AI company Alchemiq