obsolete: crab
swimming crab family
*Portunidae* is a family of crabs which contains the swimming crabs. Its members include many well-known shoreline crabs, such as the European shore crab (*Carcinus maenas*), blue crab (*Callinectes sapidus*), velvet crab (*Necora puber*) and lady crab (*Ovalipes ocellatus*). Two genera in the family are contrastingly named *Scylla* and *Charybdis*; the former contains the economically important species black crab (*Scylla serrata*) and *Scylla paramamosain*. [https://en.wikipedia.org/wiki/Portunidae]
portunidae
swimming crabs
requires discussion