There is no easy answer to this question. Yes, crustaceans can feel pain – they show behavioural responses to unpleasant stimuli like heat and touch. They run away from nasty things, and scientists believe that they have pain receptors.
Smooth Shore Crab
Photographer: Michael Marmach / Source: Museum Victoria
But often the question is, ‘Do they feel pain like we do?’ Almost certainly crustaceans do not perceive pain in the same way that we do. To begin with, their nervous system is very different from ours. Some events that would be devastating to a human do not seem to affect crustaceans too much – for example, it is common to find crustaceans in the wild that are missing legs.
These legless individuals seem to get around just as well as fully legged ones do, and do not appear to be feeling ‘pain’. In fact, some crabs will drop a leg, in the same way that a lizard will throw its tail, to confuse a potential predator while it scuttles into hiding.
The question of pain sometimes arises when we have to kill a crustacean before eating it. The best solution is to cool the lobster or crab in a slurry of crushed ice and salt water. When all movement ceases, knife a chilled crab by lifting the tail flap and inserting the knife all the way through the brain, or for a lobster, knife it through the centre of the head.
We cannot ask a crustacean whether it is feeling pain, so we really do not know whether its sensations are like our own.