Yellow lobster with a side of intrigue

With a spotted orange-and-yellow coloration, the lobster is perhaps one in about 30 million, specialists say. Caught in recent weeks off the coast of Prince Edward Island in Canada, the rare crustacean is now in a tank with nearly 100 other lobsters at Arnold's Lobster and Clam Bar in Eastham.

The owner, Nathan "Nick" Nickerson, received the crustacean as a gift from a friend last week and named her after his girlfriend's granddaughter.

"This is a once-in-a-lifetime lobster you'll see," said Michael R. Gagne, 46, sales manager at Ipswich Shellfish Company Inc., who gave the lobster to Nickerson. Gagne said he is sure Fiona is a yellow lobster, despite her orange spots.

A rare genetic mutation could produce lobsters like Fiona, according to Michael F. Tlusty, director of research at the New England Aquarium.

But they could also be few in number because their bright colors easily draw the attention of predators. "If you're swimming over a muddy bottom, it would be much easier to see a yellow lobster than a normal-colored lobster," said Tlusty, who has been studying lobsters for 10 years.

Tlusty, who has not seen Fiona in person, declined to say whether she is a yellow lobster, but noted she could be just as rare. Based on her weight, he estimated she might be 7 years old.

"Why was she able to survive with her coloration?" Tlusty asked. "That's something we're not quite sure of."

Nickerson, 57, said he has never seen a lobster like Fiona in all his years as a fisherman.

Perhaps this is why he gives Fiona preferential treatment. While the other lobsters get cod fish, Fiona dines on Yellowfin tuna of "sushi quality," he said. Her tough orange claws are not bound with rubber bands, making her free to snap off the legs of the tank's other inhabitants. She stands out among her neighbors, piled one upon the other as a blackish-brown mass, with only a few quivering antennae to distinguish them.

She looks regal as she stretches out her flippers and repels the advances of another lobster, perhaps a male.

"He's being very brave," Nickerson said. Lobsters can be cannibalistic, especially in tanks such as the one Fiona is in, but he said she is "not very aggressive."

David J. Casoni, secretary-treasurer of the Massachusetts Lobstermen's Association, said he has seen blue lobsters during his 35 years as a lobsterman, but never a yellow one.

"The odds of catching them [yellows] as they move around the bottom are like the odds of going out into a football field and finding a dime that someone lost 80 years ago," he said. "The blue lobster is still rare, but we get them more often."

Nickerson said he would like to keep Fiona as a pet for a while, but plans to donate her to the Cape Cod Museum of Natural History in Brewster or to the New England Aquarium, where Tlusty said officials would consider housing the lobster.

In the meantime, there's no chance Fiona might find her way into the restaurant's lobster rolls.

"Gosh no!" Nickerson said. "That would be like steaming a Rembrandt."

Nandini Jayakrishna can be reached at njayakrishna@globe.com.