Do prawns feel pain?

By Sheere Ng - Thursday, Jan 24, 2013

If prawns have a voice, would they scream in pain when you boil them alive in the soups of steamboat, a common gastronomic practice of the Chinese during any festive season?
In the realm of science, a group of scientists would probably cup their ears and shut their eyes, but there’ another group that may guiltlessly shove the jumping prawns into the deeper end of the hot soup. The thing is, researchers have not yet decided amongst themselves whether crustacean like prawns can feel pain.
A study by Bob Elwood, British expert on animal behaviour at Queen’s University, concluded in 2007 that prawns do suffer when harmed. He found his answer by dabbing acetic acid, the main ingredient of vinegar, on the antennae of 144 prawns. The prawns reacted by rubbing the affected antenna, while leaving the untouched ones alone. This response, Prof Elwood told New Scientist magazine, is “consistent with an interpretation of pain experience”.
Many biologists, however, believe that invertebrates (animals with no backbone or limited nerve cords), which include crustaceans like prawns, have too basic a nervous system to register pain. A marine biologist at the University of Aberdeen told The Guardian that crabs and lobster only have 100 000 neurons, compared with 100 billion in people. Hence, Prof Elwood’s study may only suggest that prawns have the capability to react upon threatening stimuli, but there’s no evidence that they actually sense pain.
Prof Elwood subsequently conducted similar researches but on crabs. To find out if hermit crabs suffer pain, he delivered electric shocks to the creature’s shells and found that they are more likely to come out of their shells than crabs that had not been shocked. Hermit crabs are known to prefer some shells to others, and they are more likely to reject shells they least prefer.
He then pushed the experiment further by limiting the level of shock so that the crabs would remain in their shells. He then offered the crabs a new shell. These crabs were likely to move out of their old shells and abandon them for the new ones than those that hadn’t been shocked. This, Prof Elwood concluded, suggested that crabs remember pain.
This year, he published another study on shore crabs, yielding the same conclusion. However, the subject of pain in crustaceans remains controversial and is a matter of data interpretation.
While the jury is still out on the question whether we are causing crustaceans to suffer in the course of our pursuit for fresher food, some people prefer to err on the side of caution. “To be honest I loved live prawns. They taste superb, definitely sweeter. But I also believe they do feel pain. I’ve given up eating it,” says Mr David Yip, a food blogger, who adds that he has not eaten live prawns for 15 years.
But others like Ms Loke See Wah, also a food blogger, are more pragmatic. “It begs a bigger question of where to start and where to end. You are already so deep in the water, how is one more drop going to make a difference? Since it is already doomed, I would give it respect by finishing it,” she says.
What’s your stand on this?

Images by Tris Marlis @ Makansutra