
Atlantic Blue Crab
Callinectes sapidus
Percnon gibbesi

The nimble spray crab is a fast, flat-bodied crab known for skittering nimbly over rocks and boulders just above and below the waterline.
Also known as: sally lightfoot crab, urchin crab, nimble spray crab
This crab is often confused with other flattened, fast-moving reef crabs of similar size. Check the legs: the yellow rings at each joint and the row of small spines along the front edge of every leg set it apart.
This is a flattened crab with five pairs of walking legs. Each leg carries a row of small spines along its leading edge, and the leg joints are marked with bright yellow rings.
This crab lives on rocky shores and among boulders, on both sides of the Atlantic Ocean and along the Pacific coast of the Americas. It has more recently spread into the Mediterranean Sea, where it is now found clinging to boulder habitats. In parts of its range it is often seen close to long-spined sea urchins.
This crab has been described as the most invasive decapod crustacean to enter the Mediterranean Sea, after arriving there and spreading rapidly along its rocky coastlines.
Describe what you saw and we name it, then keep every species you find in your Oceandex.