Hairy crabs don't scream, so doesn't it hurt?

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Animals like crayfish and hairy crabs don't cry or make trouble, can they feel pain?

There has long been a debate about whether crustaceans (invertebrates), including crabs, shrimp and lobsters, feel pain, The central issue of the debate is how invertebrates like hairy crabs respond to external stimuli , in the end is conditioned reflex or pain.

The nervous system of invertebrates is relatively simple, and the main function of the system is to sense external stimuli and regulate the movement of animals. Many scientists suspect that invertebrates do not necessarily feel pain, because they lack pain-related areas and are not at all responsible like the human and other animal brains.

Although a live crab is put into a pot of boiling water, it is likely to try to crawl out. In the eyes of scientists, , such a simple animal behavior may not necessarily be a response to pain, it can only mean that it has an environment for overheating stress response. is like when a person accidentally touches a hot water bottle, he immediately retracts his hand. At this moment, your behavior is faster than your brain realizes "ah, it's hot and it hurts."

This kind of conditioned reflex, the instinctive response is called "nociception", that is, single-celled organisms such as paramecia have the ability to feel nociception.

Others argue that this is an unfair comparison, noting that while there are major differences between vertebrate and invertebrate brains, their functions, such as vision, are similar. In addition, some scientists believe that crabs have actual pain nerves, but they "can't link pain and behavior, and can't remember deeply and recall."

what does this mean, if a crab does something wrong and feels pain, it can't realize that "it caused the pain", they just feel pain.

In 2014, British scientists collected 40 common shore crabs (Carcinus maenas) and gave the crabs an electric shock test.

The result was that the shocked crabs started crawling around in the tank and even trying to get out of the tank, and their hemolymph had almost three times as much lactic acid, a clear sign of stress. This can show that such a response is not a simple conditioned reflex. The

scientists also conducted electric shock tests on hermit crabs, and if the current motor exceeded the limit accepted by the hermit crab, they would abandon their shells and escape. And if the shock isn't strong enough, they stick to their shells. Knowing how to weigh whether the shell is more important or the shock is more painful is obviously not just a conditioned reflex.

Although the above experiments can prove that crabs' responses are not conditioned reflexes, their "pain system" still cannot be fully described. From the perspective of biological evolution, the only reason for meaningful pain perception is to provide long-term protection, allowing animals to obtain memories and help avoid future harm.

and often only animals with a long enough life cycle have the need to feel pain like evolution, and creatures like insects basically have no pain sensation, while the common shore crabs, hermit crabs and even Chinese hairy crabs mentioned above are good, longevity The length is only 2-5 years. In fact, the cruelty of nature makes most of them only a few months old, so they do not have such a complete "pain system".

In China, countless animals like crayfish and hairy crabs are cooked, maybe it is painless for them but a kind ofHappy and lucky.