Most anglers know cooked fish fillets by their texture and shape. When they go to a restaurant and order pan-seared grouper, they can tell when what is delivered to the table is a farm-raised tilapia.

But the average non-fishing consumer has no idea.

That’s led to rampant bait-and-switch practices among restaurants, according to the Wall Street Journal. The newspaper published an online story Friday that says consumers who go to restaurants to order fish, particularly grouper and red snapper, frequently get fillets from much cheaper fish.

Even worse, many of these fillets are imported from countries that don’t have the strict harvest guidelines of the U.S. According to the Food and Drug Administration, 90 percent of all seafood consumed in America comes from outside the country.

Red snapper is among the most substituted fish at restaurants, according to Mark Stoeckle, a researcher at Rockefeller University.

“Whey you buy (red snapper), you almost never get it,” he told the newspaper.

Switching product is easy because most consumers don’t know a red snapper from a red porgy, according to Joseph Lasprogata, whose family owns a seafood distributorship in Philadelphia.

“I could take three different fish, cut them into 8-inch square pieces and lay them next to each other, and very few people in the world could tell them apart,” he told the Journal.

Most switching of product seems to occur at the retail level. The newspaper pointed to an FDA study showing 85 percent of inspected seafood was correctly labeled at the last point of wholesale distribution.

That means consumers have to take a bigger role in investigating the authenticity of the fish they consume. The Journal recommended buyers look for one of two seals: from the Marine Stewardship Council (for wild-caught fish) or from the Global Aquaculture Alliance (for farm-raised fish).

Consumers should also avoid red snapper and grouper, the two most substituted fish, the Journal recommended, unless they are served whole.

“Most of all, go in with your eyes open and ask questions about the fish you eat,” the Journal concluded. “If you don’t get informed answers about what it is and where it’s from, it might be smart to order the chicken instead.”

2016 NOLA Media Group