Hey, Why So Crabby?

* Male crabs have blue claws. Females have red claws. So, what do you have if you find a crab with one blue claw and one red claw?

A rare creature indeed, says the Virginia Institute of Marine Science.

The half-boy/half-girl crab was pulled out of the lower Chesapeake Bay last month by David Johnson and Robert Watson, longtime watermen who said they had never seen anything like it. Scientists said the last reported dual-gender crab was seen in 1979.

The remarkable crustacean is thought to have had a genetic accident that caused its two halves to develop differently -- the right side as a female, the left side as a male. The crab's underside has the shapes of both: The male side looks a little like the Washington Monument, the female side like the Capitol dome. In the plant world, some flowers have both pollen-making (male) and seed-producing (female) parts. And some fish, worms, shrimp and other aquatic creatures are known to change their sex: starting off male, for example, and later becoming female.

The unusual crab is now living on a diet of chopped clams at the marine science institute's visitor center in Gloucester Point.

This crab has male and female traits.