# Some crabs swim with their specialized fifth pair of legs These crabs are known as the swimming crabs, or portunid crabs (family name is Portunidae). The most common species in this family is probably the blue crabs which you can find in supermarkets. ![[Blue crabs.png]] Their fifth pair of legs are flatten into broad paddles for swimming. <iframe width="560" height="315" src="https://www.youtube.com/embed/oV6sLyMZiBE?si=MkzYDPOEsQ62dzJE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe> ## Road signs - [[Lobsters swim faster backward by flexing their tails]]