Do oysters feel pain?

19 April 2009



Do oysters feel pain?


Marine biologist Helen Scales took this on...

Helen - It's a great question and something that stirs up seafood lovers a lot. You've got your oyster there; you're shucking it away, adding a squeeze of lemon juice, and they say you should see the oyster twitching if you put lemon juice on it; this shows they can sense chemicals and they can sense things going on.

Do they feel pain? Great question. I think the answer has to be probably not, but we don't really know.

Oysters have a nervous system; they can respond. They have no brain as such; they have two ganglia - or masses of nerves - around their body, but not a central brain like ours.

I don't think anyone can possibly claim that oysters are conscious, that they have awareness like higher mammals (not just ourselves but other creatures like dolphins and things).

I certainly think there shouldn't be a big problem with oysters.

There's still debate going on about far more advanced creatures, like fish. Is it cruel to go fishing for fun? Do they feel pain? That's the sort of thing where the debate goes on.

Scientists have found a lot of very sensitive receptors in the faces of fish that we think probably mean they can detect damage to their skin. But whether that's actually translated into pain is the big question we haven't go to the bottom of yet.

Is it pain as we feel pain because they go 'ouch.' Or is it, 'I know that's going on: that's something that's not good and I need to do something about it,' But not necessarily, 'That really hurts.'

There was one study that does sound rather cruel but we do need to understand these things so they did it. They took freshwater trout (this is scientists from the University of Edinburgh) and they actually injected bee venom into their lips to see what that did.

What they found was that these fish, compared to ones that just had water injected into their lips, rubbed their lips on the bottom of their tank and on the gravel. They didn't go back to feed as quickly as the ones that just had water and they rocked.

In zoos sometimes or in older zoos when they weren't designed to keep animals to keep them interested and stimulated they could develop a rocking motion to show that they're not enjoying themselves. A similar thing is happening with these fish. Something is going on and I think they can sense pain.

It's still a question we haven't answered.


The French call oysters and other shellfish “fruits de mer.” Since the French are always right, this settles the argument. Oysters are fruit, not animals.

Oysters are animals, not plants, fungi, or whatever non-animal organism is.
I cannot necessarily argue that they are sentient, but they are not fruits!

This is hilarious.

Anyone who doesn't think fish feel pain is kidding themselves. Fish have backbones, brains, and nerves. Any animal with a backbone feels pain for sure. It is difficult to test mollusks because of the brain issue, but that does not mean they don't feel pain. Why on earth do "they have two ganglia -- or masses of nerves -- around their body"?

If you eat animals, please just admit that you don't care that they feel pain. If you cared, you wouldn't eat them.

To assume that everyone who eats meat does not care about animal welfare is unreasonable and unfounded. There's no evidence that this is the case.

It's also a huge assumption that "any animal with a backbone feels pain for sure". Pain is a subjective experience; even two humans cannot agree sometimes on how much a common stimulus hurts.

You're not wrong that animals with nervous tissue have the potential to convey information about noxious stimuli, but that's not the same as feeling pain as you and I do.

Granted, a dog, or even a mouse, does react in a way that suggests that a painful stimulus is "painful" for them, but smaller animals, with simpler brains like amphibians, reptiles or fish, might experience a sensation as aversive without actually feeling that it is painful. 

Woodlice scuttle under a log to get away from sunlight. Is light painful for them? Probably not, but they take steps to withdraw from it, just as I take steps to pull my hand away from a hot stove top.

It's quite incredible that adults humans can so blatantly deny the obvious: the suffering of their fellow beings. Any child can see that a frog, a toad, a fish, a horny toad can experience pain.

You're probably not wrong, but it's a leap to say that, based on an observation of how a creature behaves, it's "feeling" pain. If I put antibiotics on a petridish, I can prevent bacteria growing in that area; the motiles ones will actually avoid that patch of the dish; does this mean microbes are also feeling pain? Probably not. So one has to be cautious about ascribing human emotions and perceptions to non-human situations.

Whilst I'm not against the notion they will feel pain, I agree with the author of the original post.. we dont know. We know that nerve damage to the spinal column in humans can result in either paralysis or a lack of sensation after x vertebrae. So that itself shows that it could be that they might not have the type of conscious processing to recognize pain in the "hurts" way same way a paraplegic wont feel a wound in their leg but they'll know that blood coming out isnt good regardless of how little processing the brain does from the wounding.

people don't realize the life cycle of food . its been around for centuries So if you want to eat meat do so if you dont well dont

As a human that has a back bone ive never felt physical pain. But please explain to me again how anything with a spine feels pain. Ive been seriously injured without knowing till someone else pointed it out. Save your supposed moral superiority for someone else and consider yourself blessed you can actually feel pain.

This article and associated video explains it better than my non-science self can:

Animals are a collection of cells, just like plants. Oysters and clams don't have brains, just like plants.

That's silly. Obviously anyone reading this cares about the pain animals feel. Trying to figure out what is okay to eat based on a cost/benefit analysis that includes the cost to what you are eating is clearly a good (and I think uniquely human) way to operate. Sometimes that isn't possible though.

For example, when put into a life or death situation, humans will resort to cannibalism. Remember that plane crash in the 70s, where everyone either a) ate the dead or b) died? No one gets judgemental about that.

There are A LOT of food insecure people on the planet now. If you are judging them for eating what they have available, you are in the wrong.

Yes, almost everything about the way people in the developed world eat (especially meat) now is terrible. Most of us are in a unique situation where we have the resources (nutritionally and informationally) to take the time to learn about what we are eating and whether we should be eating it. I personally eat shellfish and eggs, because they don't have brains and therefore have less ability to suffer. If I consume dairy I get it from local, well-treated, pasture-raised animals. My eggs come from my own very happy chickens. None of those decisions would be possible though if I wasn't a wealthy, land-owning westerner.

I would like to clarify that if by "shellfish" Anon meant "bivalves" (such as oysters, mussels, scallops, clams, etc.) then yes, that is correct, they completely lack brains and thus are not thought to experience suffering. But other animals get called "shellfish" and they very much have brains and can "feel" just like a mammal. Shrimp, lobster, crawfish, crab, squid, octopus, conch - the list goes on.


You say "yes", so please support your answer with relevant evidence.

Did you ever watch a fish being put on a hook?

And your point is?

You said does an oyster feel pain yes but your arguement was have you watched a fish being hooked. A oyster doesnt have a brain it has two ganglia and a fish has a brain... you cant compare the two. Even as a vegan I understand you cant just compare two different species as having the same sensations, pain receptors and feelings.

oysters don't have a central nervous system, they're unlikely to experience pain in a way resembling ours—unlike a pig or a herring or even a lobster. So you cant compare a oyster to a fish being hooked... I'm vegan but you have to look at evidence not feelings.

By the arguments some are proposing here, you could argue that both vinegar and bicarb experience pain because of their reactions to each other, You could set up a simple machine that responded to noxious stimuli with feedback circuitry that didn't have any capacity for retention of the details of the noxious stimuli. That wouldn't feel pain either. I guess for pain to be meaningful (and therefore actually felt by an oyster), it would have to be able to be experienced as noxious and information of it be able to be retained in some way. Otherwise it's just chemical reactions with no more meaning than the reaction between sodium bicarbonate and acetic acid. Perhaps our definition of pain might help - an unpleasant sensory or emotional experience involving actual or potential tissue damage or described in terms of such damage (i.e it can be an experience in the absence of any stimulus and just be 'felt).

The single most overlooked, and at the same time most foundational error in logic whenever anyone tries to justify human animals exploiting nonhuman animals is the irrational idea that human animals in general are morally superior to nonhuman animals. This idea can be easily disproved, and yet most people do not even question it. It is assumed to be indisputable when it's not based on, as some would have us believe, objective fact.

Unless we can explain how human animals are morally superior to nonhuman animals, whenever we try to justify humans exploiting nonhumans in the ways that we do, we can't rule out humans exploiting other humans in the exact same ways and for the exact same reasons (our mere pleasure, amusement or convenience).

All other forms of moral supremacy, from ethnic, to religious, to gender-based, etc. stem from this one basic idea; that it's acceptable to refuse the same moral consideration to another being that we accord ourselves, merely because of morally irrelevant criteria like the color of their skin, which genitalia they have, or their species membership.

The belief that humans are morally superior to nonhumans is not based on instinct. If it was, then we would not be questioning it, and therefore you would not even be reading this. And yet, it's the reason why we believe it's just fine to torture a nonhuman, who is fully capable of desiring to not suffer or die as much as a human, in ways that we wouldn't torture the worst human criminals.

The myth of human moral supremacy is almost never even examined. But when it is, it's obvious that, just like the arguments we use to justify racism, sexism, homophobia, religious intolerance, or any other irrational form of oppression, it's based on nothing more than arbitrary personal opinion (and biased, self-serving opinion at that).

The idea that humans are superior to nonhuman animals is based on the misconception that all humans have some characteristic or set of characteristics that all nonhumans lack. All of these criteria are obviously as arbitrary as gender, ethnic membership, or religious belief when it comes to moral superiority, since we can't prove that either they are possessed by all humans, nor that they are lacked by all nonhumans. Not only that, but whichever faculty is being discussed is always one which is possessed by the person arguing on behalf of Human Supremacy.

Although human animals created a concept of morality, many humans commonly break the moral codes imposed by society. This is why we have human slavery, rape, torture, murder, and all the other atrocities that civilized humans abhor. Nonhuman animals, who cannot be proven to understand the concept of a human moral code, almost always follow our moral codes better than we do.

They do not enslave us, create concentration camps, weapons of mass destruction, torture chambers, or pollute or otherwise destroy our habitats. Nor do they wage war on humans, or any of the other atrocities that humans are guilty of. They merely wish to be left alone to live and die on their own terms. To claim that they should have to follow our moral codes to benefit from them would be like claiming that we should punish a severely mentally handicapped human for failing to pass the S.A.T.s.

On the other side of the coin, humans enslave, rape, torture or murder nonhumans by the hundreds of billions each year, merely because we enjoy the taste of their dead bodies and secretions and the conveniences that it affords us. And we also are intentionally destroying every wild habitat that we can. We regularly treat nonhumans worse than we would treat the worst human criminals. So who is morally superior to whom again?

The idea that we should be able to do these things because say, a lion eats a zebra is ridiculous in the extreme. A male lion often will kill a rival male and their offspring before copulating, in public no less, with the mother. If a mother lioness gives birth to a severely ill or deformed baby, she will usually cannibalize them. When applied to human contexts, do we think these are morally justifiable ways to behave?

This is where the Human Supremacist says "Either we are morally superior to animals, in which case exploiting them is fine, or we aren't morally superior to them, in which case we can kill them merely because we want to consume them, just like any other animal does."

However, this completely fails to recognize that claiming one is "morally superior" means that one adheres to a code of fairness and justice more than the other does, not that one can merely understand human concepts of morality. If a human can understand the concept of the injustice of slavery, rape, torture or murder, but does not refuse to engage in such behaviors, where is the moral superiority in that?

As I mentioned, we very rarely hold completely to our optimal code of conduct. We claim, as a society, to believe in The Golden Rule, but we routinely inflict massive unnecessary suffering and death on innocent beings merely for our pleasure, amusement, or convenience. We enslave, rape, torture and murder upwards of a trillion nonhuman animals each year merely so we can unnecessarily eat their flesh and secretions and use their body parts for clothing (among other things), which causes massive suffering for them.

We should realize that if we don't follow this system of justice regarding every innocent animal, nonhuman or human, then the same arguments we use to attempt to justify inflicting unnecessary suffering and death on them ("that animal isn't as smart as I am", "they don't have souls", "it's how I make a living", "meat/fish/dairy/eggs/honey tastes good", etc.) can also be used by other humans to justify inflicting unnecessary suffering and death on us ("that person isn't as smart as I am", "I'm one of the chosen people and that person isn't", "I wanted their stuff", "rape feels good", etc.).

There is no way to morally justify the intentional, unnecessary exploitation of nonhumans by humans without also morally justifying the intentional, unnecessary exploitation of humans by other humans. This means that if we personally are in favor of violating nonhumans' right to be completely safe from being enslaved, raped, tortured, slaughtered or in any way used as replaceable resources, then we have no claim that we ourselves should be safe from having those same things done to us by other humans. Any argument we try to use to justify harming nonhumans can also be used successfully by other humans to justify harming us in those same ways.

This also means that until we as a species evolve past our irrational belief in intentionally exploiting nonhumans merely for our trivial interests, we will continue to endure racism, genderism, homophobia, ableism, tyranny, mass murder, and all the other human rights atrocities we commonly abhor.

I agree with a lot of what you said however I don't follow the logic that claiming moral superiority justifies inflicting unnecessary suffering. Wouldn't claiming moral superiority actually lead to reducing that suffering? Depending on the standard you are looking at, humans are superior to other animals. We are better at achieving certain things and obviously have more brain power. We are supreme also in the sense that we are now running the show on earth more or less and our power over the earth, not to sound cliche, comes with responsibility. We do have dominion over animals and we do get to decide their fate, as well as the rest of the natural environment. That being said, we have to treat them with respect and not destroy just because we can. Like you brought up as well, rape isn't okay just because it feels good. Are men generally more strong physically and can overpower women and rape them if desired? Yes. Does that mean rape is justified? No. That's the appropriate manner when looking at how to treat sentient beings.

I kill and eat animals with brains. So does most/all omnivores and carnivores. Trying to say that it's wrong is just like saying a bear or opossum is wrong. Millions of years of survival of our ancestral species dictated we eat meat or die. I dont think we are above other species. I think we are one of many species. One that eats meat and likes it.

Whilst I chose not to eat animals, you are completely correct in your assertion. Logically, argument of the initial poster is totally flawed. If we are not morally superior to other animals, surely we can't take a superior moral position to other animal behaviour, such as killing and eating other animals. I think what you are missing here is not that certain people think we are morally superior, rather that the vast majority of people assume that everything else experiences the world in the same way we do. What scientists in these cases are trying to establish is whether or not this is the case, without assumptions. Is it possible for a creature with no brain or central nervous to experience pain in the way other creatures do? Possibly, but that's why this research exists.

The appropriate manner to treat sentient beings is very simple: treat them the way you wish to be treated. It's called the Golden Rule.

Totally agree… treat All animals, mammals and sea creatures the way we want to be treated.

Whether an animal has a brain, ganglia, or nerve cord - it can sense touch to varying degrees. God created all life and programmed each according to its existence for which it was created for. God officially gave Man permission to eat meat after the Great Flood of Noah. Prior to the Fall of Man in Eden, all life was created to be vegan (herbivorous), yes, even sharks, snakes, t rexes, and other carnivores and omnivores! God created Man to be separate and distinct from all other Animals. We are morally superior. Not perfect due to sin, but, morally superior. Human anthropomorphism of animals is not in accordance with God. Killing animals for food is not cannibalism or wrong. God said we can. We don't have to, but we can! Killing for food and being cruel are not mutually inclusive! This is the problem with a society that strays from Biblical Christianity and left to our own speculations about everything! When most Americans were Ruralites (i.e. farmers and ranchers), we had a more practical, natural, and common sense world view! Since most Americans are Urbanites nowadays, we've become a society of snowflakes, pantywaists, and thin-skinned morons with way too much idle time on our hands to philosophize and conjecture about nonsense and asshattery!

Dude this is a SCIENCE website. If you were looking for a sermon on your preferred religious fairytale, try your local church, or a Christian website. And leave this website to the adults who are interested in evidence-based conversations.

Your Rude!!!!

What god? An imagined "god" is an excuse to take the life of another.

Studies have been done on Plants to prove they do in fact have feelings and they respond accordingly after being mistreated, experiencing kind treatment and they even respond accordingly to positive and negative thoughts/emotions...Studies on Water prove the same.

Can you provide us with links to the supporting data that bears out your comments about plants having feelings and responding to emotions please. 

I'm doubtful that any peer reviewed data exists...

As per ancient Indian culture and is also thriving today the belief, that every living being has a soul and ability to sense pain and pleasure.
People may not aware that 34 percent of 130 crores of Indians are vegetarians. Even egg is also considered as non-veg food for them. For these masses, beings non-vegetarian is equivalent to incurring sin. Salute to this culture.

You guys do realize that almost every death in the nature is painful then. Predators eat their victims practically alive..

True, but animals kill for survival. We as humans do not need to kill other animals to live.

"We as humans do not need to kill other animals to live."

Yes we do. Do some research on overpopulation and the consequences for the herd. There's a lot that could be said about humans and overpopulation as well, I'm sure we will see our own share of troubles once population hits critical mass.

You say "once population hits critical mass" - but I think it already has... Agree with you though.

Google surplus killing. Plenty animals kill for what seems like pleasure.

Humans also twitch when acid is applied to their sensitive areas - I think that's pretty good proof oysters do feel pain. Bottom line - if you must kill, then kill quickly and cleanly. Don't eat live animals (even oysters) that's just proof of a stupid person or a sick mind.

Sensible post is sensible.

The article just said oysters clams do not have brain. Your the proof stupidity. Stupidity is evil.

"Your the proof stupidity."

Good grief.

Clams are food, man. Eat and enjoy. We help keep animals from becoming overpopulated, and we nourish ourselves at the same time. Overall, it's a win-win. We lend nature a helping hand, nature nourishes us.

This dude gets it. ^

This is so stupid. How vacuous can someone be to assume that oysters are not conscious simply because they do not have a "brain" that resembles that of one typically found in a mammalian species - as noted above. Regardless of what else this article has to say, oysters do indeed "feel", but not generally in the same sense that humans can relate to. They most likely feel pain, given that it is a natural response to being harmed; and shucking an oyster, as you can imagine, is the greatest harm you can do to such a creature. But, the main point of all of this is - who really gives a s**t. They are at the bottom of the food chain, and their pain should not be a concern of humans, given that the oyster should simply be perceived as a source of great nutrients.

did you just make up your own definition of what is consciousness? possessing consciousness or not is completely reliant on whether if the organism has a brain or not, a brain is able to register pain because of other higher functions that must be executed in the brain in order to get a response. possessing nerves without a brain to process it would mean they cannot feel the pain because pain receptor is within the brain!

also by your explanation, we could also assume plants are conscious too because they also react towards external stimuli (e.g. sunflower rotating to the direction of the sun and carnivorous plants that can grab their food).

As a human who has only experienced humanity in a world of scientists who have also only experienced humanity, who are you to say plants are not conscious. You have never been a plant, so you can not reasonably speculate what its like to be a plant. Scientists identified our human brain as our source of human consciousness because we have experienced our own consciousness and we investigated. We have not experienced anything from the point of view of plants because we are not plants so there is nothing for us to investigate. So to say whether or not plants are conscious is an assumption or unreasonable speculation. Nothing wrong with that though. Speculate on

I agree that we only experienced humanity so scientists don’t know if their statements are correct. Therefore we can only know about humans.

Similarly we cannot know a rock is not conscious. We cannot experience being a rock. Silly scientists could say a rock has no capacity to transmit or process information and is just a fixed mostly unchanging structure of atoms but have they ever been a rock? Didn’t think so. Phony science m I rite?

Nah but seriously. Consciousness is a word that means something in human terms. There are tests that can be applied to evaluate it. Certain structure of information processing in life might be a grey zone for consciousness where we can’t know for sure and can’t test reliably. And other structures are so primitive they could in no conceivable way even at our most conservative meet the definition we have for consciousness. Ignoring our ability to model other life’s experience because we are not that life is just the denial of science.

Bivalves have an endogenous opioid system, which exists to mediate pain and pleasure... so yeah.

Brains are overrated. Most of the people commenting here seem to be doing fine without one.

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