This is an emotive and controversial subject, and one that I have often pondered. The way a fish takes off at high speed when feeling the hook suggests that it does, or is this just a reaction to the restraining influence of the line ?
We are told that a fishes’ nervous system is very much less sensitive than our own, and that they do not feel pain in the same way we do, but I must admit I always thought they did feel some form of pain, until one day something happened that made me change my mind.
Two boats were trolling around a feeding school of Skipjack Tuna. One boat hooked a ’skippie’ but almost immediately lost it. However the lure did not seem to be running right and seemed to have something still on the hook.
The line was reeled in and it was found that an eye was impaled upon the hook !. Obviously a ’skippie’ had been foulhooked in the eye and the whole eye had been yanked out.
A few seconds later the boat on the other side of the school hooked a fish which they boated, but it was found that this fish was minus an eye, and the empty socket was still bleeding !
This showed that, quite obviously the same fish had continued feeding as if nothing had happened, despite having its eye plucked out, and was quite ready to take another lure. Perhaps fish do not feel pain after all.
Sometimes one catches a fish that has obviously suffered horrendous wounds inflicted by sharks and other predators, and yet have survived incredibly well despite this, such as the Mako that had a broadbills’ bill driven right through its body, and the marlin that had most of it’s rear body bitten off by a shark. Both these old wounds would have killed a mere human, but the fish were in good condition .