Danno --
You're missing the point: this is exactly where science comes in, where you don't want issues to be decided by personal belief systems.
There's ample research being done on pain in fish. Lynne Sneddon at Liverpool has been in the popular press quite a bit recently because she's been doing some very innovative studies. As Andy has said earlier, fish don't have a brain put together the same way as we do, so trying to compare how they *might* feel pain to how we feel pain is comparing apples to oranges. Or, if you want a better analogy, like saying a PC program doesn't work because it doesn't run on a Macintosh. The two systems are different, so you can't make 1 to 1 comparisons.
The problem with defining pain in fish has been (and remains) that simply detecting and avoiding a source of pain doesn't imply the animal feels pain. When we touch something red hot, we pull away by reflex long before (in neurological terms) our brain registers the thing as being hot, let alone painful. The point here is that this reflex prevents us hurting ourselves. By analogy, if a trout bites an angler's hook and then tries to swim away, it *might* be feeling pain, but then again, it *might* simply be reacting to something causing harm.
As far as the animal scientists go (and they are, after all, the only people in a position to judge) the definition of pain is that an animal not only reacts to the harm, but changes its behaviour afterwards. To take an example, if we sprain our ankle, we not only "feel" the pain, but also *change* our behaviour to try to avoid causing more pain by putting weight on the ankle. More importantly to the definition, the changes we make to our behaviour are
negative ones -- we walk more slowly and more clumsily -- trading avoidance of pain against doing things like finding food or escaping from predators. A
positive change in behaviour, such as not touching hot objects,
isn't evidence of pain, it is evidence of learning, because this new behaviour doesn't diminish our ability to do things, but rather improves them. Practically all animals can learn to avoid bad things: even slugs and worms.
OK, so what she's been doing is damaging (temporarily) certain structures on a fish to see if the behave differently. One experiment was injecting acid into the lips of trout. The acid obviously would "sting" like a bee sting. In her experiments she also used some trout that were injected with saline, which would cause no "sting" and so acted as the control. The trout that had been treated with acid went off their food and exhibited odd behaviours including rubbing their lips against solid objects and rocking from side to side. According to the scientists involved, these were similar to what you'd expect from higher animals like mammals (i.e., signs of "rubbing" something to make it feel better, and exhibiting stress behaviours from pain). The trout injected with saline didn't show any of this, clearly demonstrating that these odd behaviours followed on from the sting of the acid, not from being handled by the scientists or from the needles.
To be fair, not all scientists accept that this study proves conclusively that fish feel pain, but many do. It is considered by the Royal Society of London, the oldest scientific society in the world, to be the "first conclusive evidence indicating pain perception in fish". Dr Sneddon puts it simply: "This fulfils the criteria for animal pain".
As someone who actually has worked on animals in labs and has a zoology degree as well as experiencing of teaching biology, the whole question of animals and pain is something I feel should not be skated over glibly. If you want to believe that fish do not feel pain, that's fine and that's your right. But the scientific argument isn't there to support you. The people doing the research aren't hippies and they're not bunny-huggers. They're genuinely interested in knowing of the things we do to fish cause them suffering.
If you want to follow up the stuff I've described above, please have a read of
this and check out the bibliography at the end.
Cheers, Neale
Oh just stop it Andy! You don't have to act like a little twit. This is a scientific section and I personally think that it would be a smart idea to stick with things that aren't mental because this subforum won't be be about science anymore, it with be "I think that the fish feels lonely, don't you? No, I think it want to swim with the beach ball!!" Garbage. You will just end up with a whole group of hippies tring to find out how to fish "feels".
