Paddle-legs
Guides
Portunidae
Swimming Crabs
Portunidae is a family of true crabs distinguished by their swimming ability, conferred by flattened fifth pereiopods modified into paddles. The family includes economically significant species such as the blue crab (*Callinectes sapidus*) and the velvet crab (*Necora puber*). Members are typically fast, aggressive predators with strong, sharp claws. Several species have become invasive outside their native ranges, particularly in the Mediterranean Sea via Lessepsian migration through the Suez Canal.