Regulations on the sale of fish punish those who plan to do right by their fish, and have no effect whatsoever on the idiots who buy fish without knowing what the hell they're doing. So they can't buy a Pacu. They'll just buy some other fish, and kill it. Meanwhile, people who desire to own Pacu (because they are NOT worthless, but are, in fact, interesting fish with a lot of personality, if kept CORRECTLY) are unable to do so. The result? The idiots go buy Oscars, Aros, Gars, etc., and kill them, and responsible fishkeepers are punished for no reason.