Description: Broader than it is long, making it roughly diamond shaped, the carapace length is up to around 1 cm. Colouration can vary from red to yellow-grey, often with brown red speckling or with pink and orange banding. Small tubercles on carapace. Branchial region strongly inflated, which gives noticeable raised sections on carapace. Front claws equal in length.

Habitat: Muddy sand, stones or gravel from lower shore to shallow sublittoral.

Distribution: Few records from Northern Ireland and some from the west coast of Ireland. Recorded around all coasts of Britain but mostly absent from north-east Scotland. Probably under-recorded due to being inconspicuous.

Similar Species: Could be confused with other Ebalia species. Careful inspection of carapace shape required, inflated branchial region diagnostic.

Key Identification Features:

• Broader than it is long giving ‘diamond’ shape distinctive to Ebalia sp.
• Small tubercles on carapace.
• Inflated branchial region, making noticeable raised sections on carapace.

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

iNaturalist: Ebalia tumefacta at iNaturalist World Species Observations database.

WoRMS: Ebalia tumefacta at World Register of Marine Species. Accepted name: Ebalia tumefacta (Montagu, 1808). AphiaID: 107302.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Malacostraca; Eumalacostraca; Eucarida; Decapoda; Pleocyemata; Brachyura; Eubrachyura; Heterotremata; Leucosioidea; Leucosiidae; Ebaliinae; Ebalia