Can fish feel fear or pain?

[Manky Sanke]

Who's got an opinion on this and why?

[Gazza]

In short yes i beleve they do.

[Brockp]

Hi Guys;

Well pain is a funny thing. It is very subjective and minor pains hurt more when you are unhappy or miserable about life in general i.e. there is an emotional element to the perception of pain in man. There is a lot of evidence in primates, happy monkeys with arthritis behave like they have less pain than unhappy (hungry etc) monkeys.

There is a good theoretical argument that says that the behaviour we see in non primates when they “experience” is not pain as we know it but a simple “flight and fight” response to survive. They try to move away from the painful stimulus and produce a shot of the stress hormones to enable a rapid escape.

The animal liberation gurus will say this is clap trap and of course all animals “experience” pain in a painful way rather than as a stimulus to run or fight but the evidence to my mind is weak.

So sorry I am sitting on the fence and saying I don’t know. I think the experience pain as a stimulus to get away from but I am not sure they experience pain with the overlays of emotion that we and other primates do. However I treat all my fish as if they do experience pain like I do just to be safe in case I am reincarnated as a fish the next time round !

Peter

[carlejo]

I would have thought that any living creature can feel or is sensitive to pain...... they have blood running through veins, nerve endings, so by my rational thinking if they have nerves they must feel pain.
cheers
Carl

[sam51]

hi all. i think , fish get spooked now and again.so i guess,that is a part of fear,if not they would all be feeding out of my hand.which my fish have never done,or my fish are all females,with permanent pmt, .
as for pain,i don't know,and you probably couldnt prove it,when i went fishing,and you caught them.were they fighting to get free,because of pain. or was it because you were pulling them in a direction they didn't want to go. who knows.

[carlejo]

http://www.wellcome.ac.uk/en/pain/micro ... ture2.html

[welsh_kai_boy]

I am with carl, sums it lovely.

[Geoff9]

Hi Syd
Not too sure but I remember many years ago seeing a picture in a newpaper where sharks were feeding and in the rush for food a shark got injured as it was eating another shark was eating him and it didn't seem to know,

Now have koi got feelings of empathy,I had a koi that was very poorly and struggling to stay upright other koi were at it's side trying to help it stay upright,I held the koi in my hand and most of the koi came round my hand as though they new I was trying to help,thats when I fell in love with my koi,

Hi Sam
Most of my koi feed from my hand,keep trying and they will get use to you sticking your hand in full of food,I also use alcohol wash before and after feeding them.

Regards Geoff

[Pond Life]

I suppose it depends on how you define fear, humans and animals think in different ways. Fight or flight is a basic survival instinct in reaction to perceived danger rather than the result of cognitive thinking so yes, I do think all animals feel fear.

[Manky Sanke]

Some interesting replies. Here's my take on the subject. Sorry it's a bit long but there's a lot to understand.

Fear
Living creatures that are potential prey for predators can adopt one of two main strategies. One strategy is to simply out-breed the predation rate as many insects do. For example, aphids feeding on a plant will continue feeding even though a ladybird is amongst them eating as many as it can. No matter how many aphids the ladybird eats, the rate at which they reproduce is so high that predators can't eat them all and the colony will survive. A second strategy to a threatening situation is to exhibit a "fear response" that causes potential prey to adopt a behaviour that gives each individual a good chance of survival. This might involve standing their ground and fighting off an attack or getting out of the threatening situation as quickly as possible. In general, fish are not equipped to fight so the usual strategy is to swim away and hide.

Since it is obvious and well known that sudden or threatening movements near a pond will cause the fish to immediately react in a defensive way, it needs no further proof that there is a fear reaction of some kind taking place, but is this similar to the human concept of fear? I believe it is and this is my reasoning.

The fear response in fish is measurable by analysing blood samples since this response causes a chain of reactions including the release of several hormones, such as cortisol and epinephrine, into the bloodstream. These shut down all body functions that are non-essential in the short term such as digestion, the immune system and growth etc. They also increase the heart rate, respiration and prepare the muscles for a sudden explosive release of ATP (adenosine triphosphate). ATP is a complicated chemical but, amongst its other functions, it can be regarded as giving muscles their power to perform. All animals, including humans, use ATP. If you need to run away from a tiger, you need all your muscles to perform for a short time at far higher power than normal or you will be eaten. An explosive release of ATP is what allows them to do this.

What is happening when the fear response hormones are being released into a fish's bloodstream is that all body resources are being made available to react to the situation, and in carp, this means to get away from a threat as quickly as possible. As soon as the situation becomes safe again, these hormones are no longer being released, the heart rate and respiration return to normal and the other suspended functions, such as digestion and immune system etc can resume. But blood sample analysis shows that, if a fish cannot swim away from danger or an environment it doesn't like these hormones persist.

When humans are exposed to a dangerous situation, whether it is accidental like suddenly being chased by a tiger, or whether the situation is deliberate as in the case of bungee jumping or white water rafting, we get the "adrenaline rush" feeling. This is due to stress hormones being released into our bloodstream and our body's reaction to them. Our fear response can be unpleasantly frightening or deliberately stimulating according to taste, but even if an individual enjoyed a short term deliberate stimulus, would living in danger with no chance of escape still be enjoyable? I think not. Living in continuous fear would be unpleasant.

And this is where I believe we can draw an analogy with fish. Whether it can be argued that the "fight or flight" reaction to a short term threat might not cause them any great distress, the continuous release of epinephrine and cortisol etc into the bloodstream as a result of a permanently stressful situation will cause a continuously elevated heart rate and respiration. These hormones also cause reduced digestion, immune system etc. I would argue that if the fish cannot resolve this unnatural situation by swimming away to safety, it would be similar to the human concept of living in fear.

Pain
It is often argued that fish cannot feel pain. I take the opposite view based on research into fish behaviour by L. U. Sneddon in 2003. In this research, rainbow trout were given injections of bee venom and acetic acid in their lips. Their respiration rate increased and they didn’t feed for three hours. They were also observed to be rubbing their lips against the sides of the tank and rocking from side to side on their pectoral fins during this time. To test whether this was a reaction to the venom or to the injection itself, a control group were given a saline injection. This control group didn’t show a great increase in respiration and resumed feeding in a little over an hour. This showed that although a harmless saline injection caused a slight change in behaviour for a short time, an injection of bee venom and acetic acid caused a greater behavioural change for much longer. Did this prove that the fish experienced pain from the venom injection but not from the saline injection? The research went one stage further. The experiment was repeated but this time the fish that were injected with venom and acetic acid were also given a pain killer, (a morphine injection if I remember correctly), and this produced a noticeable reduction in the rubbing behaviour with no increase in respiration.

So to sum up the way I understand the research: A harmless saline injection in the lips produced a short term slight behavioural change. An injection of bee venom and acetic acid produced a longer term reaction of increased respiration, rubbing the lips, rocking and not feeding. An injection of venom and acetic acid followed by a pain killer produced less reaction and no increase in respiration. In my book, that proves that there is a definite pain response in fish and it is similar in nature to how a human would react if they were the subject of this type of experiment and I think it proves that fish can feel pain in much the same way as a human.

Or have I missed something?

[kayoss]

Hi Syd

Not had time to get to this until now, so I thought I'd reply before reading your thoughts!

I think koi must feel fear simply because they will swim away as soon as they are spooked - simply because their natural defence is flight rather than fight!

Do they feel pain is not quite so simple IMHO. I'd guess that because they have a nervous system, they must sense things (pressure, touch, heat, chemicals etc.) and these must cause some stimulus in the brain, some possibly quite pleasant, but others less so - but is it pain? What is pain?

Have you ever been to the doctor and tried to explain exactly what symptoms you're experiencing? Your brain is obviously receiving some unpleasant stimuli from some part of your body, but what is it, where is it or how severe is it? Is it an ache, or is it throbbing? Is it stinging or is it burning? Is it in your back or your shoulder, your head or your ear? How much does it hurt on a scale of 1 - 10? Assuming their are no language problems between the patient and doctor, I'll bet, if we could expose 10 patients to exactly the same stimuli, they'd all describe it differently. Add a different language and it's almost impossible, introduce a completely different species that doesn't talk or use similar gestures as we do - and I think we'll only ever be able to guess the answer!

Koi obviously experience sensations that they find uncomfortable and that cause them distress (why else would they try to jump when ammonia levels rise), but how similar the sensations are when a koi's skin or a human's skin is exposed to ammonia, who know's? Is it the same or very similar, is it more like the sensation we experience when we touch a stinging nettle, or is it something totally different?

Answers on a postcard to.....

Cheers

Bob

[kimr]

Hi

This is a good question and in the 9 year's of keeping Koi I have changed my whole outlook on what fish can feel.

Concerning fear, my answer is yes. If you have ever had a pond which has had a visit from a preditor, say a heron, then when the fish see a shaddow of a bird they flee and dart about. The other thing is, if you have a pond where your Koi will gladly trust you and hand feed or just follow you around which mine are more than happy to do at all time's, but you need to catch one and that pan net goes into the water the tamest of Koi will get away from you as quickly as possible. But use a smaller net and they again will follow you around watching what you are doing. It is the same with a pond vac, now that could cause untold damage, but put that nozzle in the water and they are round it like bees round a honey pot. How do they know the pan net is more of a risk????????

As for pain, I believe they do feel pain, not only in the water, as anyone who has fish with parasite's and flukes being one of the worst, the fish will rub against thing's not only because they have an itch but as if to try to get rid of an irration. If you treat a fish with a deep wound or a broken bone and it is asleep when you catch a sore part or you have to cut the bone, although they are asleep they will flinch.

So in my humble opinion they do feel fear and pain