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.

Portunid crabs are characterised by the flattening of the fifth pair of legs into broad paddles, which are used for swimming.

[1] This ability, together with their strong, sharp claws, allows many species to be fast and aggressive predators.

[1] Swimming crabs reach their greatest species diversity in the Pacific and Indian Oceans.

[2] The following species are recognized in the family Portunidae: Extinct genera are marked with an obelisk.