We like to think fish have no feelings. And yet the idea that they have both memory and a capacity for suffering is gaining ground among scientists.
In the past 15 years, Braithwaite and other fish biologists around the world have produced substantial evidence that, just like mammals and birds, fish also experience conscious pain. ... “Fish do feel pain. It's likely different from what humans feel, but it is still a kind of pain.”
Fish feel pain.
Read That Sentence Again: Fish feel pain.
Yet, in recent years, scientists, researchers and biologists — all presumably with their decks intact — have been pushing back on our old ideas about fish pain. One professor has argued that the brains of certain ray-finned fishes are “sufficiently complex to support sentience.” Other academics wrote — in a paper confronting fish-pain skeptics, no less — that fish and other aquatic species “meet [the] criteria for sentience, including the ability to experience positive and negative emotions.”
Fish Feel Pain. In her book Do Fish Feel Pain?, biologist Victoria Braithwaite says that “there is as much evidence that fish feel pain and suffer as there is for birds and mammals.” ... Neurobiologists have long recognized that fish have nervous systems that comprehend and respond to pain.
Not only is scientific consensus squarely behind consciousness and pain in fishes, consciousness probably evolved first in fishes. Why? Because fishes were the first vertebrates, because they had been evolving for well over 100 million years before the ancestors of today’s mammals and birds set foot on land, and because those ancestors would have greatly benefited from having some modicum of wherewithal by the time they started colonizing such dramatically new terrain.
The fish on the end of my line would try unsuccessfully to swim for their lives as I dragged them in. Suffocating and terrified, they would thrash about while I took my time removing hooks (sometimes even standing on the fish to keep them still), organising other lines and finding my camera for that all-important photo.
Because fishes lack faces like ours, we assume that their mask-like features mean they do not experience feelings. And because fish cannot cry out, we interpret their silence as meaning they do not perceive pain - even as their gasping mouths and flopping fins on a ship’s deck indicate otherwise.