Description: A small hermit crab, with the carapace only reaching a size of up to 5 mm. Body colouration is usually grey-brown, but can be variable. Pincers are unequal in size and normally have blue and white markings. They are covered in short spines and hairs. The antennules are reported as being violet-blue. The walking legs are grey-brown in colour, with white markings and longitudinal red-brown stripes, they also have some hairs. The rostrum is triangular and protrudes noticeably. The eyes are on long, narrow stalks with longitudinal red/white striping, and the eyes themselves are usually spotted red with a white background.

Habitat: Found from the lower shore down to depths of around 80 m. Reported amongst algae, seagrass and rocky or coralline substrate.

Distribution: Seems to have a northern distribution in Britain and Ireland, with most records from Northern Ireland and Scotland.

Similar Species: Could be confused with other species of hermit crab, especially juveniles. White and blue markings on pincers may help to distinguish this species. Eyestalks and eyes are distinctively coloured in Cestopagurus timidus.

Key Identification Features:

• Small hermit crab, only reaching up to 5 mm.
• Red-spotted white eyes on long, narrow eyestalks.
• Eyestalks have longitudinal red and white striping.
• Walking legs have white markings and red-brown longitudinal stripes.
• Triangular rostrum that protrudes noticeably.
• Pincers usually have blue and white markings.
• Antennules reported as having violet-blue colouration.

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

iNaturalist: Cestopagurus timidus at iNaturalist World Species Observations database.

WoRMS: Cestopagurus timidus at World Register of Marine Species. Accepted name: Cestopagurus timidus (Roux, 1830). AphiaID: 107226.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Malacostraca; Eumalacostraca; Eucarida; Decapoda; Pleocyemata; Anomura; Paguroidea; Paguridae; Cestopagurus