Prawns feel pain

Next time you drop a marine crustacean into a pot of boiling water you should feel a twinge of guilt, because new evidence suggests that the creatures probably do find the experience decidedly uncomfortable.

Queens' University Belfast researcher Robert Elwood and his colleagues dabbed acetic acid (vinegar - how appropriate!) on one of the two antennae of 144 prawns.  The animals then spent the next 5 minutes rubbing the affected antenna in the same way that a mammal rubs a sore patch of skin, evidence, say the researchers, that these animals feel pain.

"The prolonged, specifically directed rubbing and grooming is consistent with an interpretation of pain experience," says Elwood. But some critics are unconvinced, arguing that the animals, which lack a brain, were just trying to clean the affected antenna; others have also pointed out that even single celled organisms like bacteria can sense a threatening chemical gradient and move away from it, but not because it's painful.  But Elwood points out that such comparisons are wrong. "Using the same analogy, one could argue crabs do not have vision because they lack the visual centres of humans," he says.  But if it does turn out to be true then the discovery adds credence to the old adage "no pain, no gain", because prawns taste great!