Gulf Crabs in Alabama Waters

The blue crab (Callinectes sapidus) is the crab we are most familiar with along the Gulf of Mexico coast. Boiled, picked, in gumbo, fried or baked they are a popular seafood along the coast.

Their scientific name is a combination of Latin and Greek: Calli, beautiful; nectes, swimmer and sapidus, savory – a beautiful savory swimmer.

The males will mate anytime after their third or fourth molt during maturity. The females will mate only once during their life (sorry ladies). When the female is ready to mate she releases a pheromone into the water and this serves to attract the males. The female can only be fertilized after she has shed her shell so once a male finds a female close to ready the male will clasp the female with one pair of his legs and haul her around until she is ready to mate. After mating the male will continue to protect her for a few days until her new shell hardens. As part of the mating process the female stores enough sperm to spawn one to two times during the next two years. After a female has mated she never sheds her shell again.

Blue crabs mate primarily in low salinity waters in estuaries and rivers from April through June and September through October.  The females produce 1.75 to 2.0 million eggs per spawn that are a quarter of a millimeter in diameter. The larger the female the more eggs produced. The eggs attach to the underside of the female and are a bright yellow. As the eggs mature they turn orange and then black just before hatching. The eggs and their subsequent larval stages become a part of the plankton that provides food to other marine organisms along the aquatic food chain. Spawning takes place in high salinity water in passes and near shore.

There are eight different species of blue crabs in the Gulf of Mexico.

Females have red claw tips the males do not. Blue crabs are cannibalistic with their own kind making up around 13% of their diet.

This blue crab came right out of Little Lagoon in Gulf Shores Alabama.

The top-of-page illustration is from www.Blue-Crab.org
It is a great blue crab website.

This text is from Dr. Skip, a weekly column on marine biology and ecological topics written for Gulf Coast Newspapers in Baldwin County, Alabama primarily in the Islander since 2002.  See Dr. Skip Online Here.

Read the current Alabama regulations on catching crabs (scroll to crabs info)

Photo of  Miller Wilder holding a blue crab from Little Lagoon