or scroll even further and see the lionhead. It is beyond me how people can purposely breed those grotesque varieties of goldfish. Surely the poor fish can't be comfortable.
As for pain in fish... for every scientific study that says they don't feel pain I can list 5 that says they do. Fish lice are certainly felt as the fish tries to rub them off by scaping their body over gravel.
The marine cleaning fish is visited by huge fish so that parasites can be picked off. A similar false cleaner fish has learned to take advantage of this and take a small bite out of the 'customer' who reacts violently, this has to be in response to pain.