Plenty of foods come surrounded by urban legends . Hot dogs and genetically-modified organisms, for instance, come with a cadre of rumors -- some true, some patently false. But if a recent segment on "This American Life" is to be believed, it may be time to add calamari to the list.

The popular radio show's Jan. 11 episode focuses on doppelgangers -- people and things that appear extremely similar on the surface but are actually totally different.

Among the doppelgangers? Calamari's modest cousin, "imitation calamari ."

Though it has a shape and texture similar to the real thing, its component parts are decidedly different. While calamari comes from squid, the replica is supposedly made of hog rectum, otherwise known as "bung."

The irony is not lost on Ben Calhoun , one of the show's producers, and ring-leader of the segment, who notes:

In restaurants everywhere, right this second, people are squeezing lemon wedges over crispy, golden, rings, dipping the rings into marinara sauce, and they're eating hog rectum. Now they're chewing -- satisfied and deeply clueless. It's payback for our blissful ignorance about where our food comes from and how it gets to us.

Mark Wheeler, an employee with the USDA's Food Safety and Inspection Service (FSIS) -- the department tasked with ensuring the correct labeling and packaging of our nation's meat products -- told The Huffington Post he wasn't aware of any products specifically labeled as "imitation calamari." If it does exist, and is derived from a hog's rectum, he said it would have to be clearly identified as such.

However, Wheeler did note that pig intestines are edible and are more commonly referred to as "pork chitterlings," a product the USDA notes has a "pungent odor" when boiled and a texture similar to (you guessed it) calamari.

What's more, Steve Haruch, a journalist for the Nashville Scene, claims to have chowed down on pork bung and concluded, "prepared the right way, it could pass for calamari ."

So is hog rectum getting passed off as calamari at restaurants across the United States? It's unlikely (not to mention illegal), but there really isn't any proof one way or another. Thankfully, "This American Life" didn't uncover any anecdotes of bung-based bait-and-switch practices in America's restaurants.

"We found compelling belief within the American meat industry that this is a practice," said Calhoun in an email to The Huffington Post, "but we weren't able to prove or disprove that belief. Because of that, we decided we'd take the story in a funny direction, and focus on a question we could still answer -- whether it was possible -- whether fried bung would taste and feel like calamari."

That said, a disconcerting report from Oceana, an ocean conservation watchdog, notes that seafood fraud occurs at shocking levels in major metropolitan areas, including Boston (48 percent), Los Angeles (55 percent), Miami (31 percent), and New York City (39 percent).

The group concluded that seafood fraud can happen at any step of a product's supply chain -- the restaurant, the distributor, or the processing and packaging phase.

UPDATE: January 23 -- In an emailed statement to The Huffington Post, FSIS spokesperson Richard McIntire explained the agency's labeling rules and requested anyone with knowledge of mis-labeled squid products contact the USDA:

FSIS requires that products we inspect, including those derived from pork, must be accurately labeled and cannot purport to be a product of another species. Additionally, FSIS is not aware of situations where pork bung has been sold as products derived from other animal species, like squid for calamari, and we would encourage anyone who is aware of any such violations to report them to us so we can investigate.

Listen to the entire "This American Life" segment for a blind taste-test of fried calamari and fried pork rectum. The results are certain to entertain.

Clarification: This story has been updated to emphasize "This American Life" didn't uncover any instances of pork-based imitation calamari being passed off as real calamari in a U.S. restaurant.

Correction: An earlier version of this piece mistakenly referred to the Nashville Scene journalist as Steve Karuch. His name is Steve Haruch.