For some Florida Keys residents and visitors, Oct. 15 rivals their birthday as their favorite day of the year. Why? Because that date marks the opening of the annual stone crab season — with “presents” that aren’t wrapped in colorful paper and bows, but instead are piled high on plates with dollops of tangy mustard sauce.

Florida Keys stone crab

A seafood processor at Keys Fisheries in Marathon, Fla., shovels stone crab claws into a container. (Photo by Bob Care, Florida Keys News Bureau)

The orange-red, pale yellow and black stone crab claws contain a sweet and tender meat that’s among the Keys’ most popular delicacies. During the harvest season, which continues until May 1, they’re served at gourmet and casual restaurants from Key Largo to Key West, triggering a virtual stampede of seafood fans.

Typically the claws are satisfyingly large, closer in size to a big Maine lobster’s claws than a blue crab’s claws. Their commercial harvest dates back to the 1930s in Keys inshore waters, and the hard ocean floor and favorable environment support healthy local crab populations.

Area “foodies” sometimes engage in a lighthearted dispute over whether the mouthwatering claws are best eaten hot or cold. Either way, they’re generally cooked immediately after being brought to the dock, usually by placing them in boiling water for seven to eight minutes. Running cold water over the cooked claws keeps the meat from sticking to the shell.

When it’s time to chow down, though, bring on the dipping sauce. To make the traditional dip for stone crab claws, mix a favorite mustard with mayonnaise or sour cream, plus extras like Worcestershire or A-1 sauce, and salt and pepper to taste.

Stone Crab eating Florida Keys

Sally Mishmash (left) and Sandra Bradshaw feed each other stone crab claws during a past Stone Crab Eating Contest at Marathon’s Keys Fisheries. (Photo by Andy Newman, Florida Keys News Bureau)

The Keys are Florida’s top supplier of the prized claws — which are considered a uniquely sustainable and renewable resource because of the crabs’ ability to regrow harvested claws. Each year, hundreds of thousands of pounds of stone crab claws are served at local markets and restaurants or distributed around the nation.

One of the most popular spots in the island chain to savor stone crab is Marathon’s Keys Fisheries. The super-casual eatery lies in an industrial region off the Florida Keys Overseas Highway, right on the waterfront and surrounded by commercial docks.

A favorite gathering place for locals, the establishment has a funky atmosphere that perfectly exemplifies the Keys’ laid-back style. And its stone crab claws have a fresh-off-the-boat flavor that just can’t be topped.

In fact, each year Keys Fisheries is the site of an undisputed food-centric highlight — the Stone Crab Eating Contest. The quirky competition, this year set for Saturday, Nov. 2, draws enthusiastic amateur eaters and their fans. The challenge begins at noon, and contestants are given a daunting task: crack, clean and eat all the meat from 25 stone crab claws in the fastest time.

Florida Keys stone crab

Stone crab claws with mustard sauce are a favorite at Keys restaurants and annual food festivals.

Although all entrants are provided with industrial-strength shell crackers, some choose to employ an effective method that’s popular among Keys locals — smacking the rounded area of the claw’s shell with the back of a large serving spoon or a simple butter knife.

If a tie occurs, the tied contestants must face off in an additional 10-claw competition to determine the winner.

Prizes such as overnight stays and passes to Keys attractions and eateries await the top three finishers and top teams. And proceeds from the event benefit a Marathon-based charity.

So how do you enter? Interested crab consumers (who must be at least 18 years old) are encouraged to register early to secure a spot at the contestants’ table. The individual entry fee is $50 and two-person teams can register for $100.

Whether you choose to compete in the contest or enjoy sustainable stone crab at a more leisurely pace, one thing is certain: the succulent crustacean claws are a singular sensation — and a can’t-miss dining experience for visitors to the Florida Keys.