Description: This worm has a smooth cylindrical body, ranging from 60-210 mm in length, with 30-100 chaetigers. The overall colour is golden or bronze, usually with a metallic green sheen. There is a prominent blood vessel running down the body which is visible as a red stripe down the back. The palps are noticeably large, whilst the antennae markedly shorter than the palps, and the tentacles are only as long as the width of the body. Towards the rear of the animal the cirri are very long, coming well out past the lappets. This worm is very active.

Habitat: Amongst algae, mussels or kelp holdfasts around the low water mark.

Distribution: Recorded from all around Britain and Ireland.

Similar Species: May be confused with other nereids, although with experience this species may be identified in the field. Careful examination of proboscis, dorsal cirri and lappets may be required.

Key Identification Features:

• Medium sized worm 60-120 mm long.
• Prominent blood vessel running down body, visible as red stripe.
• Large palps.
• Antennae markedly shorter than palps.
• Dorsal cirri are 3-4 times length of lappets towards rear of animal.

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

iNaturalist: Nereis pelagica at iNaturalist World Species Observations database.

GBIF data for Nereis pelagica

WoRMS: Nereis pelagica at World Register of Marine Species. Accepted name: Nereis pelagica Linnaeus, 1758. AphiaID: 130404.

Classification: Biota; Animalia; Annelida; Polychaeta; Errantia; Phyllodocida; Nereidiformia; Nereididae; Nereidinae; Nereis