Description: The distinctive rectangular shape of this crab’s carapace is diagnostic. The colour ranges from yellow to red and there is a spine at each front corner. There may be a violet-purple border to the carapace. The retractable eye stalks are long and thick, with a short, straight lobe between. The pincers range from yellow to orange are very long and slender, with coarse teeth. In males they can be up to five times the length of the carapace.

Habitat: Mud and sandy mud in which it can burrow. Found to depths of 100 m.

Distribution: Found on all coasts of UK and Ireland but rarely recorded on eastern coast of UK, from NE Scotland to SE England.

Similar Species: Unlikely to be confused with any other species.

Key Identification Features:

• Distinctive rectangular shape to carapace.
• Long, thick eye stalks.
• Long, slender pincers. In males these can be up to five times the length of the carapace.

Distribution Map from NBN: Goneplax rhomboides at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Goneplax rhomboides at iNaturalist World Species Observations database.

GBIF data for Goneplax rhomboides

WoRMS: Goneplax rhomboides at World Register of Marine Species. Accepted name: Goneplax rhomboides (Linnaeus, 1758). AphiaID: 107292.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Malacostraca; Eumalacostraca; Eucarida; Decapoda; Pleocyemata; Brachyura; Eubrachyura; Heterotremata; Goneplacoidea; Goneplacidae; Goneplax