Acrylamide is a nasty neurotoxin. Look at old protein biochemists and their hands all shake from years of making SDS-PAGE gels without gloves.

Nobody is saying that fish are moral agents that can empathise with other beings. That doesn’t man that they’re not moral subjects; the ability to understand that one is causing harm is not a prerequisite for the ability to suffer oneself. I think everyone knows this intuitively, but it does feel good to have our less moral habits be justified by memes that we would otherwise find to be illogical.