Emerald green paddle worm (Eulalia clavigera)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



A long, thin, dorsally flattened worm, between 2.7 and 9.4 cm in length, composed of ca 134 segments. It is a conspicuous worm, deep emerald green in colour, although males are lighter in colour and juveniles are light green. A few specimens may have dark brown spots may be present along the bottom of the parapodia. The head (the prostomium) is triangular (heart-shaped) but noticeably wider than it is long. The head bears five antennae and two reddish-brown eyes. The median antenna is halfway between the eyes and the front of the head.  The proboscis is long and club-shaped and covered by diffuse conical papillae that increase in size towards the open (distal) end. The opening is surrounded by a ring of larger papillae, usually 14 (but sometimes between 28 and 30). The tentacular cirri on segment one are short, spindle-shaped and reach segments two to three. Dorsal tentacular cirri on segments two and three are longer and reach segments seven and eight. The parapodial lobes (paddles) are rounded. The end of the worm (pygidium) bears two anal cirri that are 3-4 times as long as wide. 

Recorded distribution in Britain and Ireland

Recorded from the south and south-west coasts of the UK and north-west Ireland but records might have been misidentified as Eulalia viridis.  It may be widely distributed around the coasts of Britain and Ireland (see additional information).

Global distribution

Recorded from France and the UK, but probably distributed in the Iberian Peninsula and Madeira and possibly the Mediterranean (Bosne et al., 1996).


Found widely in crevices, barnacle and mussel beds and on kelp holdfasts from the intertidal to the shallow sublittoral. 

Depth range


Identifying features

  • A long, dorsally flattened polychaete, between 2.7 and 9.4 cm in length, composed of ca 134 segments.
  • It is deep emerald green in colour although juveniles and males are lighter.
  • The prostomium has two pairs of short antennae and a fifth, median antenna between the dark red eyes.
  • Dorsal tentacular cirri on segments 2 and 3 are longer and reach segments 7 and 8.
  • The ratio of the length to the thickness of the midbody dorsal cirri varies from 3 to 3.5.
  • The minimum diameter of the papillae on the proboscis is 45 µm near the head (proximal) and 65 µm near the opening (distal end). 

Additional information

Bonse et al. (1996) separated existing records of Eulalia viridis into two species based on morphological characteristics and isozyme polymorphism. They attributed the species name Eulalia viridis to northern specimens from the west coast of Sweden, Denmark, Germany, Norway, Faroe Islands, Iceland, and west Greenland to Disko Island in Baffin Bay.  They attributed the species name Eulalia clavigera to specimens from France and the UK, although they suggested it was probably distributed in the Iberian Peninsula and Madeira and possibly the Mediterranean (Bosne et al., 1996). However, Bonse et al. (1996) only examined specimens from the North East of England (Newcastle upon Tyne) so it is uncertain if only one or both species occur in the UK, at present.  The two species are difficult to distinguish without detailed examination under a microscope, therefore, existing records may confuse the species. 

Listed by

- none -


  1. Bonse, S., Schmidt, H., Eibye-Jabobsen, D. & Westheide, W., 1996. Eulalia viridis (Polychaeta: Phyllodocidae) is a complex of two species in northern Europe: Results from biochemical and morphological analyses. Cahiers de Biologie Marine, 37 (1), 33-48. DOI https://doi.org/10.21411/CBM.A.3348C329

  2. De Kluijver, M.J., van Nieuwenhuijzen, A., Ingalsuo, S. & Veldhuijzen-Van Zanten, H., 2022. Macrobenthos of the North Sea - Polychaeta. Marine Species Identification Portal. ETI Bioinformatics. [cited 2022-06-09] Available from: http://species-identification.org/species.php?species_group=macrobenthos_polychaeta&menuentry=inleiding


  1. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

  2. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-15


This review can be cited as:

Tyler-Walters, H., 2022. Eulalia clavigera Emerald green paddle worm. In Tyler-Walters H. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 15-06-2024]. Available from: https://www.marlin.ac.uk/species/detail/2355

Last Updated: 14/06/2022