Scaly Rock Crab

Plagusia squamosa

The Scaly Rock Crab, known scientifically as Plagusia squamosa, is a marine crustacean found predominantly in the tropical Indo-Pacific oceans. Its carapace is distinctively bumpy and coarse, resembling scales, which gives the crab its common name. The Scaly Rock Crab can be mistaken for the Sally-Light-Foot crab, but it can be distinguished by the shape of its labe and the coaxial joints of its walking legs. These crabs exhibit a wide range of colors, including shades of brown, blue, purple, and orange. They typically have a body width of five to six centimeters, with short and slender pincers and long walking legs fringed with short hairs and pointy claws. These crabs are primarily found in intertidal and oceanic zones throughout the Pacific region, often occupying rocky shores. They are also known as rafting crabs due to their tendency to cling to pelagic marine animals like sea turtles or floating objects. Although they are largely confined to Indo-Pacific waters, they have recently been spotted in the Mediterranean Sea, possibly due to human introduction or ecological changes. The Scaly Rock Crab's diet mainly consists of plant material and small amphipods. Divers encountering the Scaly Rock Crab may find them harmless and typically solitary. They are not evaluated for conservation status by the IUCN, and there is no specific threat to humans. Observing these crabs can be an interesting experience as they exhibit unique behaviors like rafting and a variety of colorations.