photo from US National Parks Gallery
Latin Name: Callinectes sapidus
Species: Marine Invertebrate
Conservation Status: Not Evaluated
These swimming crabs are much wider than long, with a sharp spine on each side. Males get larger than females and can reach up to 9 inches from point to point. Their back pair of legs are flat and paddle-like. Their carapace (back) is blue-green with red spines and blue legs. Males and females can be distinguished by their claw color (males, blue; females, red) and the shape of their underside, or apron. Males have a thin, tapered apron shaped like a rocket or the Washington Monument; females have a broad, rounded apron resembling the Capitol dome.
Range & Habitat (map)
Blue crabs have a wide range along the Atlantic coast of North and South America from Nova Scotia to Argentina, and into the Gulf of Mexico. While blue crabs can inhabit deeper waters, they tend to be found in shallow waters near grasses and oyster reefs.
Diet
Blue crabs are opportunistic predators and will feed on almost anything they can find, including clams, mussels, oysters, decaying plant and animal matter, and even smaller crabs.
Life History
Males molt and mate several times in their lives, but females are believed to only molt once and mate afterward. Mating mostly occurs in brackish water, peaking in March to July and October to November. Males protect the female during her molt and soft-shell stage before mating. Females carry their eggs in a spongey mass under the abdomen and cannot be harvested during this time. Once hatched, crabs go through many stages with distinct body shapes before maturing after 12-18 months. They live 3-4 years.
Significance
Blue crabs are economically significant because they are harvested commercially and recreationally to be eaten. Blue crab populations can be highly variable from year to year, so it is important to evaluate trends in populations rather than absolute numbers. Overharvesting and loss of habitat threaten blue crab populations.
Threats & How You Can Help
If you fish for blue crabs, it is important to understand and obey regulations regarding size limits, catch limits, and seasonal restrictions put in place to protect crab populations. Purchasing a Saltwater Fishing License is required to harvest crabs in South Carolina, and also contributes money towards the conservation of this important species.