From microscopic plankton to intimidating, deep sea lantern fish, the creatures that live in the ocean are as varied and unfamiliar as if they lived on another planet. Among these strange looking alien creatures, the geoduck of the Northwest Coastal U.S. has earned a reputation as one of the weirdest looking (it might make you blush) and most delicious mollusks to meet the American plate. Here, now, is a primer on this sand burrowing bivalve.

What is a geoduck?

First off, it's pronounced "gooey duck." Contrary to what one might think, it's not related to a duck at all. The Nisqually — a Native American tribe located in western Washington — coined the term gweduc, meaning "dig deep" and referring to the way this bivalve burrows far below the seafloor. Europeans later reinterpreted the native spelling and pronunciation.

Geoduck is a large clam with simple anatomy. There are two major parts to remember: the siphon or neck, which hangs out of the shell, and the mantle (also called breast), the meaty part that sits inside the shell. Native to the Pacific Northwest and Western Canadian coast, geoducks anchor themselves into the ground with a small "foot," and remain in one spot for their entire lives. Several feet below ground, the massive saltwater clam sucks in seawater, filtering for plankton and precious vitamins, and squirts out the excess through its impressive siphon. Their necks easily stretch from banana to baseball lengths, depending on how comfortably situated they are (they're happiest and longest when they're underground).

The geoduck is the world's largest burrowing clam, and typical specimens weigh between 2 and 3 pounds. It's far too big to retreat to its shell like other mollusks; instead, the massive neck promiscuously hangs outside in all its phallic glory. Since the geoduck burrows below the floor, you can tell you're in the presence of a geoduck when you spot two of its siphon holes peeping up from the ground. George Young, author of The Rewards of Scuba Hunting, likens the sight to staring down into a double barrel shotgun.

So, what does it taste like?

Geoduck meat is sweet and clear in taste. Seattle-based chef Ethan Stowell features geoduck seasonally at Goldfinch and How to Cook a Wolf. "It's definitely unique to the Northwest, and I think we should be proud of it," Stowell says. "It's a raw clam, and it's as sweet as it gets for something that comes from the ocean."

A delicate, crunchy texture distinguishes the geoducks from other mollusks too. "When it's raw, it has that crunchy clam quality that I think is very unique to the geoduck," Brandon Jew, San Francisco-based chef and owner of Master Jiu's, says. "Because of how dense the trunk is, when you cut it very thin on the bias, you get a specific kind of snap when you bite into it."

And if the texture and taste aren't enough to please, these wrinkly creatures are also heralded as aphrodisiacs — especially in China. Scientific explanations for these unique properties are few and far between. (Maybe they just spark love because it's nearly impossible to look at a geoduck and not think of a penis.)

Why does everyone freak out about them?

Wouldn't you? Phallic and extreme in appearance, a geoduck looks like something in between a prehistoric bottom-feeder and Jabba the Hutt's infant grandchild. Siphons can grow up to three feet in length, and a shell can reach football proportions. With lifespans up to 150 years, geoducks are also one of the longest-living animals in the world, adding to their intrigue.

Geoduck comes at a high price; the sought-after delicacy is sold in U.S. markets for 20 to 30 dollars a pound. "When you put it pound for pound, it's three times as expensive as foie gras," Stowell says. "It's definitely a specialty item."

The geoduck may be fairly obscure throughout the United States, but in the Pacific Northwest, geoduck occupies cult status and people adore the geoduck with great relish. Speedy the Geoduck is the mascot of Evergreen State College in Olympia, Wash., and supposedly represents the essence of Evergreen: "accessible to all who are willing to dig deep." Evergreen's inspiring battle cry goes like this:

Go, Geoducks, go, Through the mud and the sand, let's go, Siphon high, squirt it out, swivel all about, Let it all hang out!

The giant clam has inspired other sorts of tributes as well. The mockumentary Love Mussel features Kevin Smith as a dedicated journalist covering the story of a New Zealand town that discovers its local harvest, geoduck, harbors unique Viagra-like properties. Geoduck has also been featured on Good Mythical Morning's segment "Will It Chocolate?" (see 9:10), Top Chef, Bizarre Foods, and Dirty Jobs.

How are geoducks harvested?

Geoduck harvesting is a visceral process. Workers wade into cold, muddy Pacific waters only to wrestle with muscular mollusks reluctant to leave their homes. According to Modern Farmer, many geoduck farmers use high pressure water hoses to harvest geoducks. A blast of water into the sandy substrate geoducks call home loosens the sand and dislodges a geoduck from its stronghold. At this point, the harvester thrusts their arm into the hole they've created and uproots the giant clam. Geoduck hunting is something of a recreational sport in Washington, and hunters use garden shovels and plastic digging tubes to uncover clams in the wild — there's even a song about it.

Geoduck harvests represent an $80 million a year industry for Washington state and the Province of British Columbia, The Rewards of Scuba Hunting notes. The clam is exported by the hundreds of thousands of pounds — representing more than 90 percent of the U.S. industry harvest — to Southeast Asia (China, Korea, and Japan) each year, where it's heralded as a delicacy, specialty item, and aphrodisiac.

But geoduck aquaculture is controversial, and industry growth with current techniques isn't sustainable, University of Washington scientists have reported. Geoduck farms utilize the state's natural coastlines, and baby geoducks are "planted" inside protective PVC pipes that stud the coast and disturb its habitats. High-pressure jet harvesting breaks up the natural substrate, traumatizing an increasingly delicate ecology and shoreline. Efforts to improve sustainability within the industry include studying off-the-ground or contained system farming techniques.

How is geoduck prepared?

Before you cook a geoduck, you have to properly clean it. "They're actually very easy to clean," chef Brandon Jew says. "It's a quick blanch, and then you basically pull off the outer membrane. You can pretty much slice it and serve it from there."

As far as the U.S. goes, wide consumption of the behemoth clam is largely limited to the Pacific Northwest, stretching occasionally to the West Coast. Seattle-based chef John Sundstrom serves geoduck raw, or prepared in ceviche. It's also prepared in sushi, chowder, crudo, and even pie. Taylor Shellfish (the largest shellfish operation in the PNW) suggests using geoduck in a bright, minty salad.

In Japan, geoduck is called mirugai ("giant clam") and used for sashimi and sushi. Korean chefs also frequently serve it raw, with hot chili sauce, or in fiery soups and stir-fries. In China, where its name — innocently — translates to "elephant trunk," geoduck is enjoyed in hot pots. One fresh geoduck can fetch up to $300 at a high-end Chinese restaurant, BBC News reports.

Where can I taste it?

"You could find geoduck on a few menus back in the old days [25 years ago], we'll call it, when I first got [to Seattle]," John Sundstrom, chef and owner of Lark, says. "I feel like they weren't that prevalent unless you were going to primarily sushi bars or Japanese restaurants. But it's a wonderful ingredient that really speaks to the [Pacific Northwest], and I think chefs are more interested in it and getting creative with it. Around the country, I've been noticing, seeing it on menus now, and that's great."

Geoduck makes seasonal appearances on the menus at Seattle's Sushi Kashiba and in the raw, at How to Cook a Wolf, Mister Jiu's, and Bitter/Raw. Try geoduck in hot pot at the Landmark Hot Pot House in Vancouver, B.C. Not headed out west any time soon? Taylor Shellfish Farms, in Puget Sound, is the largest shellfish farm in the country and ships two pound geoducks for $60. Dig deep, and dig in.