By: Chris O'Shea
Everyone loves lobster, right? And despite the weird way of having to cook them alive, most people can take solace in the school of thought that says animals without backbones don't feel pain. So have at it! They're fine. And their dead bodies are tasty. Robert Elwood, a professor of zoology and physcology at Ireland's Queen’s University, agrees that lobsters are delicious. He does not agree, however, that they don't feel pain.
The argument over invertebrates (insects, shellfish, snails, octopi, etc.) feeling or not feeling pain has been happening for many years. In the scientific community, most researchers come down firmly on one side or the other. There isn't much grey area, even though there aren't many facts to back up either side. Those who said they do feel pain cite evolutionary reasons for pain existing, and those who don't think invertebrates feel pain often say the spinal cord is needed to feel anything like pain, so of course they do not. But in a write up this week in The Washington Post detailing Elwood's recent research on the issue (which has kind of revived the debate), Elwood scoffs at the no-pain argument. "Denying that crabs feel pain because they don’t have the same biology is like denying they can see because they don’t have a visual cortex," he smartly noted in the Post article.
In his research, Elwood used electric shock on crabs. In one test, when crabs were given a brief shock, they were more likely to move on from their shelters than those crabs who weren't given a shock. In another test, hermit crabs who were shocked slinked back into their shells quicker than hermit crabs who weren't shocked. And in still another experiment, the crabs who were shocked literally looked to be licking their wounds — they would rub the claw that was shocked and pick at wounds from every day incidents. "These are not just reflexes,” Elwood explained in the piece. "This is prolonged and complicated behavior, which clearly involves the central nervous system."
And it looks the ability to feel pain extends to other items on the seafood menu. The same article also talks to Robyn Cook, an evolutionary neurobiologist at the University of Texas Health Science Center. Cook recently discovered that cephalopods, squids and octopi, have something called nociceptors, which are basically tiny cells that send signals to the brain when its damaged — it's the general source of the pain sensation. We should note though that Cook's research seems to indicate cephalopods don't register specific pain, instead becoming aware of the general area on their body that's suffered a wound.
Despite these findings, the debate will continue. In the end, pain is a very difficult thing to test for, and it's completely subjective. So what one crab or squid "feels" another crab might not. In other words, the next time you order lobster or calamari, just convince yourself that you have the one who don't feel any pain, and you'll be good to go.
[Image via Flickr - WM Naki]