Half-male, half-female, all crab

Fishermen caught a crab in the lower Chesapeake Bay that's literally half male, half female. Among other differences, male blue crabs have deep blue claws while females' claw tips look like they were painted with red nail polish. The fishermen noticed that this particular crab had one of each. Researchers at the Virginia Institute of Marine Science say that the condition, known as bilateral gynandromorphism, is caused by a "chromosomal mishap." Studying the rare animal could increase understanding of crab sexual development and breeding behavior. From the Washington Post:

 Wp-Dyn Content Photo 2005 06 16 Ph2005061600466
Before turning over the crab to the scientists, (boat captain David) 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.

Link to Washington Post article, Link to Virginia Institute press release (Thanks, Vann Hall!)