Blue Crab Anatomy

blue crab anatomy

Dorsal View -- Male Atlantic blue crab (Callinectes sapidus)

An easy way to tell the difference between an adult male and female crab is look at a crab's underside and examine the shape of its abdomen. By looking at the abdomen you can see the difference between adult males, adult females, and juvenile females.

The male has an abdomen (or apron) shaped like the Washington Monument. The female has a rounded abdomen, shaped like a honey comb, or like the Capitol dome in Washington, D.C. Immature female crabs have an abdomen that's more shaped like a triangle