Part Male, Part Female, Fully Mysterious

Now, the crab lives in an aquarium in the reception area at the Virginia Institute of Marine Science in Gloucester Point, Va. The creature is eating voraciously and showing no signs of health problems.

Kimberly Reece, a scientist at the institute, said the crab's condition probably resulted from what she called a "chromosomal mishap" shortly after it was conceived. As the cells began to divide, at one point a sex chromosome was lost or changed -- and as a result, the two halves developed according to different genetic blueprints, she said.

That means the crab could help scientists understand a crab's genetics and early development, which remain mysterious despite the creature's ubiquity around the Chesapeake.

"At what point in its development is its gender fixed?" asked Romuald N. Lipcius, a crab expert at the institute.

There are other questions: Can the crab reproduce? Can it mate with itself? Mating season has come and gone for this year, Lipcius said.

"It's possible that it already mated with itself," he said.

Before turning over the crab to the scientists, Johnson and other watermen conducted their own experiment into its sex life, with bewildering results. They dropped a female crab, which was just about ready to mate, into its tank.

First, the half-and-half crab cradled the female under his legs, as a male crab would do in preparation for mating.

Then, the crab seemed to lose interest in the female and let her go, Johnson said.

Then a day later . . .

"He ate half of her," Johnson said.

"The first day, the male side was coming out, the next day, it was the female side," said Lipcius, noting that in the wild, female crabs will often eat other competing females after they have shed their shells and become vulnerable.

Lipcius said that after the crab dies, it will be mounted and put on display at the institute next to another crustacean celebrity, a nearly 11-inch-wide crab that is the largest caught in the bay region.

But, he said, Johnson will always have the right to take it home to his family in Deltaville, in Virginia's Middlesex County.

Watson said the crab already has a name, Springer. The watermen thought it was strange enough to be on "The Jerry Springer Show."

"Our next goal is, I want to catch a mermaid," Watson said. "Hey, man, you never know."