- Kingdom: Animalia
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Subclass: Eumalacostraca
- Superorder: Eucarida
- Order: Decapoda
- Suborder: Pleocyemata
- Infraorder: Brachyura
- Family: Portunidae
- Scientific name: Liocarcinus navigator
- Norwegian: rettsnutet svømmekrabbe
The most distinct feature is that the frontal margin, between the eyes, is hairy and without any spines. At the other side of the eyes the margin has five spines on each side. This is a small crab, the brown carapace does not exceed a length of 30 mm and width of 33. The crab is sometimes called Liocarcinus arcuatus.
It is most frequent on sandy substrate between 5 and 10 metres, but registrations have been made as deep as 100 metres.
It is registered in the Mediterranean and the North-East Atlantic Ocean. In Norway there are registrations as far north as Trøndelag.