
Was that fish feeling pain? Fear? If a sociopath is someone who disregards the pain of others, and if someone who ignores evidence is in denial, what does that make me?
Fish have honed their skills for hundreds of millions of years; humans are just making their acquaintance. Research has shown that various fish show long-term memory, social bonding, parenting, learned traditions, tool use, and even inter-species cooperation. Compared to those, pain and fear are primitive and basic.
Although aquatic farms in a handful of countries, including the UK and Norway, must follow humane slaughter guidelines, there are no standards for considering the tens of thousands of wild fish caught every second.

Fish were ancestors to all other vertebrates; their brains were the template for our own brains’ evolution. Lynne Sneddon, director of bioveterinary science at Liverpool University, was the first scientist to discover that fish possess nerves known to convey pain. In 2002, she identified in fish the same nerve types that, in humans, detect painful stimuli. We call such nerves “pain receptors”. Sneddon showed that pinching and pricking fish activates these nerve fibres. “My research has shown that fish have a strikingly similar neuronal system to mammals,” she told me, adding that until 2002, “it was generally believed fish did not have feelings”. Nerves are not proof that fish experience pain – but Sneddon showed that fish have the necessary hardware.
The software to match this comes in the form of brain chemicals called neurotransmitters. Mammals and fish share many identical neurotransmitters including dopamine and serotonin. In humans these are involved in pain, hunger, thirst and fear, and include opiate-like chemicals that reduce pain.
Fish anatomy, neurochemistry and behaviour all indicate that fish experience sensations including wellbeing and pain. And fear.
“How can you not feel?”, outraged the famous oceanographer Sylvia Earle!! “Fish have had a few hundred million years to figure things out. We’re newcomers. I find it astonishing that many people seem shocked at the idea that fish feel. The way I see it, some people have wondrous fish-like characteristics – they can think and feel!”

When we ask if they can feel what a human feels, we imply that that is the best a fish might aspire to. But as Earle said, fish “have senses we humans can only dream about. Try to imagine having taste buds all along your body. Or the ability to sense the electricity of a hiding fish. Or eyes of a deep sea shark.” Many fish see four major colours; humans only see three. Some see polarised light, some see ultraviolet. Some, such as flounders, move their eyes independently, processing two image fields”!

Nerves, brain structure, brain chemistry and behaviour – all evidence indicates that, to varying degrees, fish can feel pain, fear and psychological stress. Must we insist on denying them even that paltry acknowledgment? If we do insist, let us be honest about why: it is too painful to contemplate!
https://www.theguardian.com/news/2018/oct/30/are-we-wrong-to-assume-fish-cant-feel-pain?
https://www.ciwf.org.uk/our-campaigns/rethink-fish/
My comment: Do we want to persuade ourselves that fish do not feel pain, so that we can bring them to the plate with a clear conscience? Is our food the only criterion for deciding on the death of others? Is this the kind of people we want to be?
Think about it
My best regards, Venus