University of Gothenburg researchers have provided scientific proof that shore crabs feel pain, urging a reevaluation of how shellfish are treated under EU animal welfare laws. This evidence supports the development of less painful methods for killing shellfish.
In our pursuit of improving the welfare of animals we consume, certain creatures are often overlooked. Researchers at the University of Gothenburg are now focusing on decapod crustaceans, which include shellfish delicacies such as prawns, lobsters, crabs, and crayfish. Currently, shellfish are not protected under animal welfare legislation in the EU, but this might be about to change—for a good reason, according to researchers.
Their study, recently published in the journal Biology, provides the first evidence that painful stimuli are sent to the brain of shore crabs, offering more proof that crustaceans feel pain.
“We need to find less painful ways to kill shellfish if we are to continue eating them. Because now we have scientific evidence that they both experience and react to pain,” said Lynne Sneddon, zoophysiologist at the University of Gothenburg.
Several research groups have previously conducted a number of observational studies on crustaceans, in which they were subjected to mechanical impact, electric shocks, or acids to soft tissues such as the antennae. These crustaceans reacted by touching the exposed area or trying to avoid the danger in repeated experiments, leading researchers to assume that they feel pain.
Pain Receptors in the Soft Tissues
The researchers at the University of Gothenburg are the first to carry out neurobiological studies by measuring the activity in the brain of a shore crab, through an EEG style measurement.
“We could see that the crab has some kind of pain receptors in its soft tissues, because we recorded an increase in brain activity when we applied a potentially painful chemical, a form of vinegar, to the crab’s soft tissues. The same happened when we applied external pressure to several of the crab’s body parts,” says Eleftherios Kasiouras, PhD student at the University of Gothenburg and lead author of the study.
The activity of the central nervous system in the brain was measured in the crab when the soft tissues of claws, antennae, and legs were subjected to some form of stress. The responses show that shore crabs must have some form of pain signaling to the brain from these body parts. The pain response was shorter and more powerful in the case of physical stress than in the case of chemical stress, which lasted longer.
Advocating for Humane Treatment
“It is a given that all animals need some kind of pain system to cope by avoiding danger. I don’t think we need to test all species of crustaceans, as they have a similar structure and therefore similar nervous systems. We can assume that shrimps, crayfish and lobsters can also send external signals about painful stimuli to their brain which will process this information,” says Kasiouras.
The researchers point out that we need to find more humane ways to handle and even kill crustaceans. At present, it is allowed to cut up a crustacean alive, unlike the mammals we eat.
“We need more research to find less painful ways to kill shellfish,” says Sneddon.
Reference: “Putative Nociceptive Responses in a Decapod Crustacean: The Shore Crab (Carcinus maenas)” by Eleftherios Kasiouras, Peter C. Hubbard, Albin Gräns and Lynne U. Sneddon, 21 October 2024, Biology.
DOI: 10.3390/biology13110851
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19 Comments
““We need to find less painful ways to kill shellfish if we are to continue eating them.
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No, we really do not.
I disagree with you.
I commend the effort and the good intentions. If they’re able to find less cruel ways to kill, that’s good.
But somewhere down the line it will be scientifically proven that the vegetables feel pain, too. Then what are we gonna do?
Certainly it will give the political vegetarians a long pause.
Animals eat each other alive. They have no concerns with whether their dinner feels pain or not as they eat it.
Really? That’s your rationale for boiling them alive? Humans are “animals”, so we should behave as some of them do? If there is any indication that creatures such as crabs and lobsters feel pain when boiled alive, then some way of dispatching them first should be found.
We are all animals.
You are entitled to your personal opinions. Just please don’t try and foster them on me or others.
So, I am “entitled to my personal opinions” – if they don’t differ from yours? And as long as I don’t express them here? The comments section of this website is not the sole soapbox for anyone. Not me, not you, no one.
Of course we are animals.
“…, then some way of dispatching them first should be found.”
Why? Because you say so? Are you capable of making an argument that is compelling?
How far up the species ladder should we go before ethics takes hold? Would you skin a rabbit alive before you make a stew out of it? If you reject the article’s contentions, so be it. I won’t apologize for my ethical views (and no, I’m not a member of PETA).
As a species we might be considered to be a part of the animal kingdom, but the inherent primitive in us should not be used as an excuse for mistreating other species.
Apparently not everyone agrees with this view, unfortunately.
If one touches a mimosa plant, it will quickly react by withdrawing as the leaf curls up. One can’t ask the plant if it feels ‘pain’ or if it is an autonomic response to the touch of what might be a predator. Similarly, I don’t see how one can be certain if shellfish actually feel and remember a stimulus as “pain,” or if it is again an autonomic response to avoid a predator. The stimulus that causes a ‘fight or flight’ response need not be pain, but it will have to involve the higher levels of the neurological system. I think that their “proof” is weak.
Even with sentient beings, such as humans, there is a fine line sometimes between pleasure and pain, particularly during sexual activity.
Do Gooders trying to change peoples behavior, rationalize what they think is causing pain with the application of acetic acid by claiming that it is in the interest of science and finding “humane” methods to prepare seafood. Pain is pain, and if the creatures are actually experiencing pain, then there is NO justification for willfully causing pain other than saving the life of the individual.
When a creature sacrifices a limb or tail to distract a predator, does it feel pain? Whether it does or not, it has apparently been a good trade off as a survival strategy.
We can try to be humane to those that are not human.
Again, why? Just because you hold the idea that we should treat our food the same as our friends doesn’t mean that it is a rational position.
If I touch a hot stove, I feel pain and I’m glad that I do because it helps me avoid something worse.
Clyde, please read my reply to your other comment from today above.
Hmmm… Yes, creatures do sacrifice limbs or a tail to distract a predator. It may simply be a survival adaptation. But even if there is less pain involved in that act than we think, can we extrapolate further and assume, for example, that a lizard that gives up its tail won’t feel pain if the predator bites into its body?
What if my lobster identifies as an artichoke? Is that a viable loophole? Nothing there’s anything wrong with lobsters, in fact some of my best friends are lobsters…
I think the real argument here is something along these lines:
I is well documented in psychology that people who routinely commit violent acts in sanctioned settings will tend to become emotionally detached from the acts through a coping strategy of dehumanizing the human victims in order to justify the inherently brutal acts. Think of soldiers and their enemies, perpetrators of premeditated violent crimes, executioners and so on. No child we consider mentally healthy starts that way. In the same manner we have slaughterhouse workers killing hundreds of animals on a regular basis. I would wager someone killing cattle, pigs, and chickens on an industrial scale without extreme emotional distress has to view those animals as fundamentally different from their pet dog or cat, even though there is no effective difference between the two.
This dehumanization of the victim or subject also demonstrably hardens the person doing these things lest they themselves suffer. This can and frequently does lead to an expanded ease with making similar decisions in other settings; the so called sociopathic trend. I’m not equating slaughtering animals with sociopathy but the strand of connection is there.
To pick a point in our collective European past: ‘The Enlightenment’ was among many things humanity’s movement out of the blindingly ignorant worst of the Dark Ages to a more sweeping perspective, understanding of impacts of our actions and a logical, factually based interpretation of the world around us. It is a work in progress, and like so many things, unstable. We can go up and become better human beings or go down and lose our humanity. And finally; it is much harder to be ‘kind’ than ‘cruel’ when challenged.