When is a red snapper not a red snapper? When you're at the seafood counter buying what you think is a premium fish.
According to a study of fish sold as red snapper, only 25% was the real thing. An amazing 75% was faux red snapper, cheaper fish trying to sneak into celebrity status.
And that's just the tip of the iceberg in the great seafood masquerade. Check out the FDA's official Seafood List of acceptable "market names." It's legal, tricky, and business as usual for seafood sellers to use phony market names to get more money for less-desirable fish.
Scary Patagonian toothfish becomes suave Chilean sea bass, and voila the price goes up. Ditto for skates and rays, sometimes cut with cookie cutters and sold as "scallops." Sebastes rockfish get sold as "Pacific red snapper" or "rock cod," despite being neither a snapper or a cod. Etc. Who knew?
In this case students in a college biology class who busted the fake red snapper accidentally, while learning DNA testing.
Mislabelling seafood is not exactly the best way for seafood sellers to inspire confidence. I sure hope they're telling the truth when they tell us not to worry about mercury in fish.