If you enjoy eating fresh crab and lobster read no further, because although many of us have been told crabs and lobsters feel no pain because they lack the biology, new research suggests otherwise.
Researchers concluded crabs feel pain by showing that crabs given a mild shock will take steps to avoid getting shocked in the future. The study results were published in the Journal of Experimental Biology.
Live Science notes that in the new study, researchers allowed shore crabs to choose between one of two dark shelters in a brightly lit tank. One shelter came with a mild shock.
After just two trials, crabs avoided the shocked shelter in favor of the shock-free shelter, suggesting they learned to discriminate between the two options, opting for the pain-free environment.
“It’s almost impossible to prove an animal feels pain, but there are criteria you can look at,” said lead researcher Robert Elwood, an animal behaviorist at Queen’s University, Belfast, in the U.K.
“Here we have another criteria satisfied — if the data are consistent, a body of evidence [showing crabs feel pain] can build up.”
Elwood was inspired to determine if crabs and other crustacean decapods feel pain after a chef posed the question to him around eight years ago.
“If the invertebrates feel pain, he reasoned, their reactions to unpleasant stimuli would be more than the simple reflex of nociception — the experience would change their long-term behavior.”
In yet another study conducted in 2009, researchers found that not only do crabs suffer pain, they retain a memory of it, prompting scientists to consider advocating for new laws related to the suffering of all crustaceans.
In this study, wires were used to deliver shocks to the bellies of hermit crabs, which often take up residence in left-behind mollusc shells. The crabs that were shocked scampered out of their shells, “indicating that the experience is unpleasant for them,” the scientists concluded; unshocked crabs stayed put.
Elwood suggests future research should explore changes in crustacean hormones or heart rates due to shock, and he feels it may be time to reconsider the treatment of decapods in the food industry.
“If the evidence for pain in decapods continues to stack up with mammals and birds that already get some protection, then perhaps there should be some nod in that direction for these animals,” he said.