Study finds crabs can feel pain
Whether or not crustaceans can feel pain remains a widely debated issue, and new research has resulted in questions over how food and aquaculture industries treat live creatures such as crabs, prawns and lobsters.
The research, carried out by Professor Bob Elwood and Barry Magee from Queen's School of Biological Sciences, involved observing the reactions of shore crabs to small electric shocks, and their subsequent behaviour.
Previous research carried out by Professor Elwood has shown prawns and crabs to behave in a manner consistent with pain, and his latest work provides further evidence in support of this. Discussing the most recent experiment, Professor Elwood explained:
“Crabs value dark hideaways beneath rocks where they can shelter from predators. Exploiting this preference, our study tested whether the crabs experienced pain by seeing if they could learn to give up a valued dark hiding place in order to avoid a mild electric shock."
Ninety crabs were used in the experiment, and each was individually introduced to a tank with two dark shelters. After choosing one of the shelters, some of the crabs were then given a small electric shock. After a rest period, this process was repeated twice. When the crabs were introduced to the tank for the third time the majority of the crabs chose the alternative, 'safe' shelter. The crabs who were never shocked continued to opt for the same shelter each time.
Professor Elwood says: "They were willing to give up their hideaway in order to avoid the source of their probable pain.
"The experiment was carefully designed to distinguish between pain and a reflex phenomenon know as nociception," he said.
Professor Elwood concludes that though it is impossible to guarantee that an animal experiences pain, this research indicates "a strong probability of pain," meaning investigations are needed into how crustaceans are treated in food industries. Crustaceans are currently given "little to no" protection and Elwood asserts: "More consideration of the treatment of these animals is needed as a potentially very large problem is being ignored."
