Description: The body of this small caprellid is spinose and the back of the body is covered in acute projections or tubercles. There are two large spiny projections on the head which are especially conspicuous. The 3rd section of antenna 1 is shorter than the second section, and both sets of antennae are covered in hairs. Pereopods 3 and 4 are absent or poorly developed.

Habitat: Reportedly found both intertidally and subtidally. Some records indicate they were attached to bryozoans such as Crisia.

Distribution: Some records from the south of Britain. None for the island of Ireland so far.

Similar Species: Could be confused with other caprellids. Careful inspection required. The two large spiny projections together with the antenna section lengths should help distinguish this species from others. Could be confused with Caprella mutica but it has no projections on the head or upper thorax, it is instead covered with dense hairs.

Key Identification Features:

• Spinose body covered in acute projections or tubercles.
• Two large spiny projections on the back of head.
• 3rd section of antenna 1 shorter than 2nd section.

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

iNaturalist: Caprella erethizon at iNaturalist World Species Observations database.

GBIF data for Caprella erethizon

WoRMS: Caprella erethizon at World Register of Marine Species. Accepted name: Caprella erethizon Mayer, 1901. AphiaID: 101831.

Classification: Biota; Animalia; Arthropoda; Crustacea; Multicrustacea; Malacostraca; Eumalacostraca; Peracarida; Amphipoda; Senticaudata; Corophiida; Caprellidira; Caprelloidea; Caprellidae; Caprellinae; Caprella