It’s a common misconception that crabs and lobsters scream as you plunge them into boiling water to cook.
But even if this myth isn’t true, scientists say there is still good reason to avoid this classic kitchen technique.
Zoologists from the University of Gothenburg are calling for an immediate ban on boiling crabs alive after making a groundbreaking discovery.
The researchers have proven that crabs really can feel pain just like any other animal, meaning that being boiled is likely to be an excruciatingly painful death.
Lead author Eleftherios Kasiouras, a PhD student at the University of Gothenburg, told MailOnline: ‘We believe that the boiling crustaceans alive should be banned and other techniques such as electro stunning should be applied the moment that the crustaceans are caught.
‘There is more and more evidence emerging, including our research, that decapods [crabs] experience pain so we should treat them as we would treat other animals.’
In their study, the researchers used brain scans to see how crabs’ nervous systems react when they are exposed to painful stimuli.
This revealed the first evidence that crabs process pain in the exact same way as humans.
Researchers are calling for an urgent ban on boiling crabs alive as a shocking study proves that they really can feel pain (stock image)
The researchers took partially paralysed shore crabs, also known as European green crabs, and attached electrodes to clusters of nerves called ganglia which make up their central nervous system.
The crabs were then subjected to painful chemical or physical stimulation using solutions of acetic acid and specialised probes.
They discovered that damage or stress to the claws, antennae, and legs caused a spike of electrical activity in the associated ganglia.
Mr Kasiouras says: ‘Our findings showed that when a painful stimulus was applied to the tissues of shore crabs, that stimulus was conveyed to the brain. These responses were prolonged and intense.’
The researchers also tested the same areas with non-painful stimuli such as salt water but didn’t see the same kind of reaction.
‘We didn’t receive any responses so what we saw was definitely not a reflex. From our findings, we saw that these were responses to pain,’ says Mr Kasiouras.
Earlier research has shown that it is likely crustaceans like crabs, shrimp, and lobsters do experience pain.
However, these studies focussed on observational methods and looked at evidence like increased touching of the affected area or trying to avoid the danger.
Researchers recorded the brain activity of paralyzed crabs as they were subjected to painful stimulation from acid and physical probes. They discovered that these tissues contained pain receptors which sent messages to the brain when stimulated
This graph shows the spike in brain activity produced when acetic acid was applied to the leg of a shore crab. The red vertical line shows the moment the acid was applied
What makes this recent study different is that it is the first to record how a crustacean’s nervous system really responds to damaging stimuli.
In our bodies, and in the bodies of many other animals, specialised receptors called nociceptors detect damage and send signals to the central nervous system which are interpreted as pain.
In their paper, published in the journal Biology, the researchers argue that the existence of nociceptors is a ‘key criteria’ for an animal to feel pain.
The neural activation observed by the researcher is a strong indication that there must be pain receptors in its tissue which are sending responses up to the central nervous system.
And, what is true for crabs is almost certainly true for other crustaceans with a similar structure and nervous system.
This, therefore, is strong evidence that crabs, shrimps, crayfish, and lobsters are all capable of feeling and processing pain.
In light of these findings, the researchers say there is an urgent need for more legal protections for crabs’ welfare.
Co-author Dr Lynne Sneddon, an expert on animal pain at the University of Gothenburg, says: ‘We need to find less painful ways to kill shellfish if we are to continue eating them.
Although they are not currently covered by EU animal welfare legislation, the researchers say their study finds that crustaceans including crabs such as the European green crab used in the trail (pictured), lobsters, shrimp, and crayfish all feel pain when killed
The researchers are calling for crabs to be stunned with electricity when caught so that they do not suffer a painful death by boiling or suffocation (file photo)
‘Because now we have scientific evidence that they both experience and react to pain.’
In the EU, crustaceans are one of the few animals not covered by welfare laws meaning there are no guidelines on how to handle them in the lab or in the kitchen.
That means it is legal to cut up or boil crabs while they are still alive, which is not the case for any of the mammals we eat.
While the researchers acknowledge that their own research was no doubt painful, they insist that as few crabs as possible were used in the hope of improving the welfare of all crustaceans in the future.
Mr Kasiouras adds: ‘In the UK, decapod crustaceans are considered sentient so definitely the animal welfare legislations should be extended to cover these groups of animals too.
‘More research is needed on that topic and we hope that we can announce some guidelines in the future.’
