I also saw an entire tank of oscars at Walmart once, all between 4-6 inches. They were all literally bone with scales on them. I threw food in their tank, but it was koi food, which was all they fed their many varieties of fish. The oscars destroyed a giant handful in under 10 seconds. Just sucks it was koi food, they needed a more nutritional meal. Don't they have inspected for these sorts of things? Do people have to own permits or anything to own a fish business? If not then they should, and they need inspections done regularly.
as for walmart it is one of the worlds worst things ever,
watch the documentary walmart high cost of low prices or something to that effect , they are destroying the world you cant believe they would give a ish about a fish