check what? You posted some links that explain a metric which was theorized to measure intelligence. That wasn't what I requested source for (it's a theory). I asked for a source that says this theory is the prevalent theory.

Btw I never made any comment about fish's brain size, I said they're generally less intelligent than farm animals, which wikipedia agrees with, fits the brain ratio theory too: https://en.wikipedia.org/wiki/Fish_intelligence#Brain

Thanks for derailing the conversation anyway, at the end, there is no such thing as a fish