Description: This caprellid reaches around 12 mm in length, although is more commonly up to 8 mm. There are some dorsal tubercles on the body, but there are no spines or acute projections. The first body segment (pereonite 1) is not elongate. There are dense swimming setae (hairs) on the second pair of antennae. Pereopods 3 and 4 are poorly developed.

Habitat: Intertidal rocky areas, often on red algae (e.g. Polysiphonia sp.) or on algae, sponges, hydroids, bryozoans etc. down to depths of over 1000 m.

Distribution: Scattered records from around Britain, so far only recorded on SW/W coast on the island of Ireland.

Similar Species: Could be confused with other caprellids, especially Caprella linearis but it has an elongated pereonite 1.

Key Identification Features:

• Dorsal tubercles, but no spines/acute projections.
• Pereonite 1 not elongate.
• Dense setae on antenna 2.

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

iNaturalist: Caprella septentrionalis at iNaturalist World Species Observations database.

GBIF data for Caprella septentrionalis

WoRMS: Caprella septentrionalis at World Register of Marine Species. Accepted name: Caprella septentrionalis Krøyer, 1838. AphiaID: 101851.

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