Professor Bob Elwood and Barry Magee from Queen's School of Biological Sciences reported the first definitive experiments that demonstrated that the common shore crab does feel pain in the Jan. 16, 2013, issue of the Journal of Experimental Biology.
The basis of the conclusion that crabs feel pain is the experimental determination that the crabs will give up something they want in order to avoid a source of pain. In this instance the desired object was dark shelter and the source of pain was an external electric shock. Crabs prefer dark shelter to avoid predators.
After experiencing two to three rounds of small electric shock, the majority of crabs that were shocked gave up a preferred dark hiding spot even though that behavior exposed them to possible predation.
Professor Elwood said: "The experiment was carefully designed to distinguish between pain and a reflex phenomenon known as nociception. The function of pain is to aid future avoidance of the pain source, whereas nociception enables a reflex response that provides immediate protection but no awareness or changes to long-term behaviour.”
Professor Elwood says that his research highlights the need to investigate how crustaceans used in food industries, such as crabs, prawns and lobsters, are treated. He said: "Billions of crustacean are caught or reared in aquaculture for the food industry. In contrast to mammals, crustaceans are given little or no protection as the presumption is that they cannot experience pain. Our research suggests otherwise. More consideration of the treatment of these animals is needed as a potentially very large problem is being ignored.
"On a philosophical point it is impossible to demonstrate absolutely that an animal experiences pain. However, various criteria have been suggested regarding what we would expect if pain were to be experienced. The research at Queen's has tested those criteria and the data is consistent with the idea of pain. Thus, we conclude that there is a strong probability of pain and the need to consider the welfare of these animals."
The shell fishing industry actually employs very few people compared to other industries. The importance of shell fish to other employers like tourism, restaurants, and food are much greater.
The bravado or perhaps foolhardiness of crab fishermen has been made particularly famous by the television program Deadliest Catch.
Realistically one cannot expect this research to change the crab fishing industry.
The research was reviewed at the Eureka Alert website the date of publication.