Can an octopus feel pain

Answer 1

One view:

Insects cannot feel pain. This is because an insectsnervous system is directly connected to the muscular system, and not to the brain.

Humans have special nerve cells called nociceptors, whose purpose is to create the sensation of pain. Insects do not have any nociceptors, so pain is not one of their senses. Things like hunger, thirst, and fatigue are among the sensations they are able to feel.

Second view:

I don't think I agree with the statement about nociceptors. For instance, below is a quote from "A Question of Pain in Invertebrates" by Jane A. Smith (http://dels.nas.edu/ilar_n/ilarjournal/33_1_2/V33_1_2Question.shtml):

"Invertebrates, it seems, exhibit nociceptive responses analogous to those shown by vertebrates. They can detect and respond to noxious stimuli, and in some cases, these responses can be modified by opioid substances."

But Smith continues by observing that nociception doesn't always imply conscious experience of pain, which may be what the first respondent was getting at.

I personally think the jury is still out as to whether insects feel pain in the same meaningful sense that people do. This piece of mine gives some further views on the question, many supporting the idea that insects suffer: Alan Dawrst, "Can Insects Feel Pain?" (http://www.utilitarian-essays.com/insect-pain.html). For instance, some insect behaviors seem hard to explain in the absence of basic conscious awareness.

Third view:

Probably not, at least for most insects.

Firstly, with the exception of the fruit fly, there are no pain receptors found in insects. In mammals, pain occurs when our nociceptors fire. The signal then travels up our spinal cord and then reaches our brain where the stimuli is processed in different areas of the brain. The limbic system then gives us the unpleasant emotional experience associated with the stimulus. Insects have neither nociceptors (except the fruit fly) nor a limbic system.

While all organisms will try to avoid negative consequences (even plants and bacteria), pain does not necessairly have to be apart of the equation, as it is simply another survival mechanism that may not be necessary for the survival of all organisms.

The view that they do not feel pain is further supported by observation. An insect with severe injuries will continue normal activity and continue to apply undiminished force to the injured regions of their body apparently without drawing attention to the injury. Also, locusts have been observed to continue feeding up until the moment of death while being preyed on by a predator.

The fruit fly may be an exception to this rule. Nociceptors have been discovered in the fruit fly. Additionally, several experiments show that a fruit fly will additonally learn to avoid negative stimuli. This may hint that the fruit fly in particular is capable of feeling pain.

While there is no 100% guarantee for anything, the current consensus is that the majority of insects do not feel pain. And by the way, Spiders are not insects.

Sources: http://insects.about.com/od/insects101/f/Do-Insects-Feel-Pain.htm

http://www.parl.gc.ca/content/sen/committee/372/lega/witn/shelly-e.htm

Putz, G. and Heisenberg, M., (2002). Memories in Drosophila heat-box learning. Learning and Memory, 9:349-359

Answer 2

It has not been conclusively proven. In one study, orb-weaving spiders autotomized (i.e. cut their own legs off) if they were injected with posionous components that induced pain. However, this was a near instantaneous response and autotomy has not been documented in most other spiders, so it may not be wise to generalize this finding to all spiders just because they found them in a very specific group. In addition, nociceptors have yet to be detected in spiders.

In summary, nobody knows for sure yet.

Answer 3

All living things, whether plants, animals, bacteria, etc, will have to respond to stimuli in one way or another, but this is not indicative of pain. The brains of invertebrates are not structured like humans, so they will likely not feel pain like we do. However, it is likely that some invertebrates like the octopus have evolved the ability to feel pain through convergent evolution. There has to be an evolutionary purpose for feeling pain, or else it would be a waste of metabolic energy and the organisms that do not feel pain would outcompete them.

Answer 4

no on YouTube a man cut up an octopus and after its head was removed it still moved