It’s a hotly debated topic among fish scientists, whether fish feel pain in the same manner as humans, despite differences in nervous systems and cognitive abilities.

Being a lay person, I’ve always been skeptical of the “cognitive” theory, which suggests fish cannot feel pain due to the lack of higher brain function. Knowing the efficiencies of Mother Nature, it seems unnecessary to build different versions of the same thing – when one pain mechanism would serve both plant and animal.

Simplistic to be sure, but recent research suggests that fish feel pain in the same fashion as we do.

“The experiment shows that fish do not only respond to painful stimuli with reflexes, but change their behavior also after the event,” Nordgreen said. “Together with what we know from experiments carried out by other groups, this indicates that the fish consciously perceive the test situation as painful and switch to behaviors indicative of having been through an aversive experience.”

Research on Rainbow Trout adds additional evidence the scientific community may soon reverse their belief that “pain” was merely a reflexive motion in fish – not a perceptive response.

The present study examined the acute effects of administering a noxious chemical to the lips of rainbow trout (Oncorhynchus mykiss) to assess what changes occurred in behaviour and physiology. There was no difference in swimming activity or use of cover when comparing the noxiously stimulated individuals with the controls. The noxiously treated individuals performed anomalous behaviours where they rocked on either pectoral fin from side to side and they also rubbed their lips into the gravel and against the sides of the tank. Opercular beat rate (gill or ventilation rate) increased almost double fold after the noxious treatment whereas the controls only showed a 30% increase. Administering morphine significantly reduced the pain-related behaviours and opercular beat rate and thus morphine appears to act as an analgesic in the rainbow trout. It is concluded that these pain-related behaviours are not simple reflexes and therefore there is the potential for pain perception in fish.

This is big news on the science front, but will be even bigger with PETA and the eco-fringe. Now that we can make “sea-kittens” cry, and knowingly maiming them for sport, we can expect another bevy of Hollywood actresses to disrobe for their defense.

Lucky us.

It won’t really change anything for us brutish fishermen unless they learn to yell. In the interim, we’ll do our best to quickly unhook the beast – and if it continues to flop around while we release it, we’ll mutter, “Man up, dammit.”