Blue crabs are a vital part of the Chesapeake bays ecosystem and the economy of people who live on the bay. We all know how delicious crabs are but how much do you know about crabs?

All of you have seen crabs hanging to the side of jetties but how much do you really know about blue crabs? We see crabs in the Chesapeake bay but they live everywhere in the Atlantic ocean from Canada to Argentina in South America. Blue crabs have even migrated to Europe, Japan and the pacific ocean after being sucked into ship ballasts and transported there.

Identifying

Male crabs are called “Jimmys” and female crabs are called “Sooks”. Immature or teenage female crabs are called “Sallys”. There are a couple of ways to tell the difference between male and female crabs. Females have red claws as if they were painting their fingernails. Males have blue claws. If you flip them over to see the white underside you will see what is called their “Apron”. Males have an apron that is slender and pointy. It looks just like the Washington Monument. Adult females have a rounded apron with a pointy top. It looks just like the dome of the Capitol in Washington. The immature females have an apron that looks like a pyramid.

Protection

The crab has a very hard shell which helps protect it from predators. Molting is when a crab outgrows the hard outer shell and sheds it. Once a crab molts it takes a while for their new shell to become hard again. During this time they are very vulnerable to predators.

These newly molted crabs are called “soft shell” crabs. Blue crabs also have the ability to regenerate limbs. This means if a crab loses a leg from a predator it will grow a new leg the next time it molts.

Reproduction

The bay is a perfect place for baby crabs to be raised in the protection of the sea grass beds. Female crabs only mate once in their lifetime. Just before mating the female crab molts. The male crabs then protect the female crabs by carrying them under their bodies. It is during this time that the crabs mate. In the winter the females burrow into the muddy bottom of the bay. In May through August the following year the females extrude the eggs and carry them in an orange sponge like mass underneath of them. This egg mass can contain up to 2 million crab larvae. Two weeks later the larvae are released. These baby crabs molt every time they grow larger until the crabs are adults after 1 1/2 – 2 years. During this time the crab will molt up to 18 times!

Predators

The natural predators of the blue crab include eels, drum, striped bass, spot, trout, some sharks, humans, and cownose sting rays. The blue crab is an omnivore, eating both plants and animals. Blue crabs typically consume thin-shelled bivalves, annelids, small fish, plants and nearly any other item they can find, including carrion and even other blue crabs.

So the next time you see a crab think about all the things you have learned about them.

Some interesting videos on crabs..