Ah ok, so just out of curiosity why is it only fish then that's generally eaten and not chicken or other white meat?
I remember the story from school, but not well enough to explain it very well. Jesus turned one loaf of bread & one fish into enough to feed hundreds. I think this is why it is fish.
I always thought it was fish only, no chicken or pork either.

We always grew up eating fish & prawns Good Friday. I don't have an issue with it either way. My kids have never been fish/seafood eaters though, so it depends for us. I try to eat fish though.

My parents owned a takeaway shop for 10 years & Good Friday was our biggest day for burgers. Not fish or veggie burgers. Beef burgers.