I'd be suprised if anyone had seen the fish in the picture above in a fish store, that is a Atlantic wolf fish (Anarhichas lupus) a cold water marine fish found in deep costal waters of the Atlantic ocean. The wolf fish people have seen in fish stores are most likely Hoplias malabaricus which is a predatory Characin from the Amazon basin, they still have teeth but are a long way from having jaws to match those of the marine wolf fish.
yeah thats what i was referring to. hoplias still have some pretty big teeth though