"This research demonstrates that it is not a simple reflex but that crabs trade-off their need for a quality shell with the need to avoid the harmful stimulus.
"Such trade-offs are seen in vertebrates in which the response to pain is controlled with respect to other requirements.
"Humans, for example, may hold on a hot plate that contains food whereas they may drop an empty plate, showing that we take into account differing motivational requirements when responding to pain.
"Trade-offs of this type have not been previously demonstrated in crustaceans. The results are consistent with the idea of pain being experienced by these animals."
Previous work at Queen's University found that prawns show prolonged rubbing when an antenna was treated with weak acetic acid but this rubbing was reduced by local anaesthetic.
The findings are both studies are consistent with observations of pain in mammals.
But Professor Elwood says that in contrast to mammals, little protection is given to the millions of crustaceans that are used in the fishing and food industries each day.
He added: "More research is needed in this area where a potentially very large problem is being ignored.
"Legislation to protect crustaceans has been proposed but it is likely to cover only scientific research.
"Millions of crustacean are caught or reared in aquaculture for the food industry.
"There is no protection for these animals (with the possible exception of certain states in Australia) as the presumption is that they cannot experience pain.
"With vertebrates we are asked to err on the side of caution and I believe this is the approach to take with these crustaceans."
|Contact: Andrea Clements|
Queen's University Belfast