Apparently it's a common myth that fish don't feel pain. I think it's because they show pain differently than mammals (for example, if a salmon let down an ear-shattering shierk when caught, I think we'd think differently) and people don't want to think about it.

People also believe that goldfish have no memory, and insects don't think or even aren't alive. You'll notice the common thread of these exonerating us for our tiny bowls and our swatting.

It's like the modern version of "animals don't have a soul".

they don't want to think about it, or they directly think that all animals doesn't feel pain (or that the pain they suffer it's not important because they are just animals and "we as humans, are above them".

As a kid I liked to go fishing with my step father, and we (or at least I) never thought about what the fish felt, as they were so different to us, and they taught us that this was normal and fun.

It was years later that I really thought about it.

My dad is adamant that fish don't feel pain. He just heard it from someone when he was young, and accepted it as fact because it made him feel better as a fishing enthusiast.

Some fishing magazines downplay what the fish experience before being murdered.

'It's OK kids, they're made out of styrofoam. They can't actually feel any pain'

Can you ethically kill your dog when they want to live?

You can make fish alternatives with carrots, tofu, jackfruit, seitan, oyster king mushrooms, chickpeas, tempeh, anti choke.

https://proveg.com/uk/fish-alternatives-10-vegan-substitutes-to-fish-caviar-and-other-seafood/

you can't kill ethically a fish, cow, pig, dog, etc.

sometimes there are "humane" times you have to kill, for some reason, another animal, because they are really suffering and it's impossible to bring them to health. anything else, is unnecessary.

There are a lot of alternatives for a plant based diet, and being healthy, you have to be informed to know what to eat, and with which thing combine it (rice and beans, together, are a complete protein). there is tofu, seitan, different types of grains and legumes that are protein complete or that you can complete between them

Edit: CW Don’t read if you don’t want descriptions of death of fish

Different ethical systems presume different things. That aside, I think the most universal thing is to minimise suffering. So it you’re going to fish, there are ways to minimise suffering of catch. It really depends your setup. But obviously the number one thing is do everything in your power to only catch things you will eat. Secondly, when you do catch something, don’t let it asyphixiate slowly to death. You can do a clean cut around the gill arches or the caudal artery. Which will hit the main veines and drop blood pressure to the brain really quick (very very quick death), this is also useful because then the fish bleeds out which prevents blood pooling in the meat from turning it rotten. Some people prefer to stun the fish before any cutting at all, so the first thing they will do, is hit something hard on the fish’s head which will immediately render it unconscious, then cut the arteries.

The whole asphyxiation to death is really the worst because it takes many many minutes and fish go through things like lungs collapsing and blood clotting which bring immense pain before being unconscious.