How do you know the difference between a male and female blue crab?

You must be brave enough to pinch the body of the blue crab from behind and lift it upside down (It hurts a lot if they pinch you!).

Male blue crabs have a distinct shape like a pencil – or the Washington Monument – in the center of their bellies. Female blue crabs, on the other hand, have a shape like the Capitol.

http://treadoutdoors.blogspot.com/2012/10/my-husband-gave-me-crabs.html

http://treadoutdoors.blogspot.com/2012/10/my-husband-gave-me-crabs.html