Description: This medium-sized ragworm grows to a size of 120 mm, but is more commonly 60-100 mm, with 90-120 chaetigers. The antennae are much shorter than the palps, and most tentacles are around the length of the body width, aside from the last pair which may be longer. There is a prominent dorsal blood vessel visible as a dark red line down the centre of the back. The overall body colour is very variable, it could shades of green, yellow or orange. Towards the rear of the animal there is one large paddle-shaped chaeta on each neuropod. The dorsal cirri are shorter than the lappets.

Habitat: Burrows in muddy sand in the intertidal. Can tolerate brackish conditions.

Distribution: Recorded from coasts all around Britain and Ireland.

Similar Species: There are several other species of ragworm present in Britain and Ireland. Careful inspection of the dorsal cirri and tentacle length will help distinguish this worm from other species when coupled with other features.

Key Identification Features:

• Medium-sized worm 60-120 mm.
• Tentacles as long as body width.
• Dorsal blood vessel visible as red stripe/line.
• Paddle-shaped chaeta towards rear of animal.
• Dorsal cirri shorter than lappets.

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

iNaturalist: Hediste diversicolor at iNaturalist World Species Observations database.

GBIF data for Hediste diversicolor

WoRMS: Hediste diversicolor at World Register of Marine Species. Accepted name: Hediste diversicolor (O.F. Müller, 1776). AphiaID: 152302.

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