- Kingdom: Animalia
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Subclass: Eumalacostraca
- Superorder: Eucarida
- Order: Decapoda
- Suborder: Pleocyemata
- Infraorder: Brachyura
- Family: Portunidae
- Scientific name: Liocarcinus depurator
- Norwegian: vanlig svømmekrabbe
Easily distinguished from the common shore crab by the paddle shaped fifth pair of legs. The two arches of light spots on the back are easy to recognize as well. The color varies from green or light brown to almost red. The carapace can grow 5 cm wide and 4 cm long.
The normal depth range is 5 to 150 meters, but has been registered on 450. It is most frequent on sand, mud or gravel.
It is known from the Mediterranean and the entire East Atlantic Ocean, from Africa to Norway.