Sticks and stones will break your bones, but names will never hurt you. Unless you're at the fish counter it seems, where the retailers Sainsbury's have 'renamed' pollack as 'colin'.
No, it's not April Fools' Day - apparently customers had a bit of an issue asking for pollack. I guess in much the same way as Uranus started being pronounced 'Yoo-ran-uss' at some point in the last couple of decades to avoid embarrassment and puerile jokes.