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Do Fish Feel Pain? Not as Humans or Mammals

Do fish feel pain like us? This is one of the most sought-after questions about fish.

Unlike humans, it is quite difficult to spot any feeling in fish. But that doesn’t rule over the fact that they are living creatures and ought to have feelings.

If you ask, do fish feel pain? The answer is yes. But unlike mammals, they are not expressive and incapable of screaming. Their pain can be traced when they wiggle rapidly to get rid of the pain-causing object. Fish feel pain when they receive pressure, caustic irritating chemicals, or get injured.

Do Fish Feel Pain? The Detailed Explanation!

Fish are comparatively meek and less expressive, it is hard to tell whether they feel pain or not.

A large team of neurobiologists, fishery scientists, and behavioral ecologists believe that fish do feel pain but not in the way humans do.

According to them, fish do not come with a much more efficient neuro-psychological capacity, which is required for conscious awareness or expression of pain. Hence, the pain of fish is not that usual like us.

Mammals usually have certain nerve fibers, known as c-nociceptors, which create intense sensations of pain.

Unlike humans, fish do not possess a neocortex. It is the very first indicator of the doubt regarding the awareness of pain in them.

A typical human cutaneous nerve comprises 83% of Group C nerve fibers. But the nerve density in fish is not even near to this percentage; thus, making them unable to feel a similar kind of pain like humans.

But the anatomy of fish is not at all comparable to humans.

Neurobiologists have recognized that fish have a nervous system, which helps them perceive pain and respond to it.

Researchers have found that more than 20 pain receptors, known as nociceptors, are in the mouth and head of some fish. These sensory receptors are present in the areas where their flesh gets penetrated by a sharp object like a hook.

Fish are higher vertebrates, they have neurotransmitters like endorphins, which relieve their suffering. If their nervous system comprehends pain in their body, they supply the natural pain reliever or painkiller to soothe their agony.

As per studies, primitive fish like rays, sharks, etc., don’t possess these fibers.

Fish like trout and carp have this kind of sensory receptors. This is why psychological prerequisites required for a conscious feeling of pain are hardly developed in fish.

Bony fish possess simple nociceptors. Thus, they show their reaction to injuries and other kinds of interventions. However, the intensity of pain felt by these fish is not as much as humans.

It’s obvious that fish won’t scream audibly to make us aware that they are in pain. How can we understand their suffering? You can spot their pain from some of their activities and behavior.

It has been seen that when fish are exposed to irritation-causing chemicals, they mostly behave like us.

They lose their appetite and have fast-beating gills. If you observe correctly, you will find them rubbing their affected areas against the wall of the tank.

As opposed to various researches, Prof. Brian Key shared on his webinar that fish do not feel pain. You can watch the whole seminar below.

When Caught

So, are you now wondering, do fish feel pain when they are caught? We all have seen that fish try to get back to water hurriedly whenever they are brought outside water.

This rapid behavior in them is a mixture of fear, an instinct for self-defense, and the last hours of getting rid of captivity.

As you bring fish out of the water, they tend to feel a shortage of breath without the supply of adequate oxygen. Hence, it is much of a suffocating feeling for them when they are caught.

In terms of their anatomy, some fish have neurons, which can detect high temperatures, potentially harmful agents, caustic chemicals, or intense pressure.

If you catch them under intense pressure or using toxic agents, their brain will perceive it as pain.

When Hooked

Do fish feel pain when hooked? Yes. Although their brains are not as complex and big as mammals to express pain aloud, when they get hooked, you’ll find them wiggling violently.

It is simply one of their unconscious reactions to their agony.

Though there are some debates regarding the sentience of fish, it won’t be a mistake to believe that they do feel pain when they are hooked, as it is evident from their restless movement and relentless jumping to get rid of it.

When Suffocating

Unlike humans and other animals, when fish are kept out of the water, they are completely unable to breathe. Unless water passes through their gills, they cannot produce oxygen for breathing.

When you bring fish out of the water, you’ll notice them wriggle hastily because they tend to lack oxygen and starts suffocating, ultimately leading to their death.

Such squirming activities of fish might be considered as a piece of evidence that they are in discomfort and feel pain.

There is a stress-related hormone known as cortisol, which significantly increases when a fish is out of water.

Dying is dependent on the type of the species. While cod and haddock can remain conscious on the deck for two hours or more, many fish die only in a few minutes.

The unique walking catfish can survive up to 18-19 hours above the water without suffocation.

When Slaughtered

Some bony fish feel pain when they get in contact with intense pressure or have any kind of penetration into their flesh, it is not unnatural for them to feel pain while getting slaughtered.

They produce some opioids, which are innate painkillers in their body. These compounds can relieve them from pain.

A fish will barely get a chance to feel pain as you kill it with a knife struck hard on its head at one shot. It will die immediately!

Frequently Asked Questions

Do jellyfish feel pain?

Jellyfish do not have a brain. These aquatic creatures only respond to the changes in the environment around them when they receive signals from their nerve net that resides right below their epidermis, i.e., underneath the outer layer of their skin.

This nerve net is quite sensitive to touches. But it is used only to get a sensory signal through their body.

Whether it can be comprehended as pain or not is quite unknown.

It is usually said that the pain experienced by sea jellies is similar to the pain of a bee sting.

Do crayfish feel pain?

Unlike other fish, crayfish or freshwater crustaceans are more unexplainable about their feelings.

While fish are always active and lively, you can barely find crayfish to move around, so analyzing their mood or perceptions is really difficult.

Crayfish are viewed as a group of fish that maintain reflexes. But it does not cause them any internal suffering.

Hence, they don’t truly feel any serious pain. And this is because reflex actions and pain signals are distinct and not correlated.

Pain signals are generated from brains. But crayfish reportedly do not have a brain like us.

Do betta fish feel pain?

Some researchers say that bettas are capable of being happy or unhappy. There is plenty of experimentation done on whether fish feel pain or not. Based on those studies, many veterinarians believe that bettas do experience pain and suffering.

Bettas are said to possess the correct anatomy for receiving pain signals. They usually produce some natural painkillers, which even mammals release. They can even consciously choose to avoid the feeling of a painful stimulus.

Sounds interesting, right!


Studies on do fish feel pain has always been a hot cake for scientists all over the world.

Some research has come up with an answer to it, many things are yet to be discovered. The latest studies say that they do not feel severe pain like us, but they do feel some kind of pain.

Whether you are hooking them or hitting them with pressure, fish will sense the stimuli and feel minimal pain in their body.

While caring for your fish, make sure you do not do anything that can cause stress or pain in them.