Marbled rock crab

''Pachygrapsus marmoratus'' is a species of crab, sometimes called the ''marbled rock crab'' or ''marbled crab'', which lives in the Black Sea, the Mediterranean Sea and parts of the Atlantic Ocean. It is dark violet brown, with yellow marbling, and with a body up to 36 millimetres long. It is an omnivore, feeding on algae and various animals including mussels and limpets.