''Eulalia clavigera'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

polychaete worm Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ma ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Phyllodocidae Phyllodocidae is a Family (biology), family of polychaete worms. Worms in this family live on the seabed and may burrow under the sediment. Characteristics Members of the Phyllodocidae are characterised by an eversible pharynx and leaf-like dors ...

, native to the coasts around Britain, through Western France, and to the Iberian Peninsula. It closely resembles '' Eulalia viridis'', and there has been confusion in the past as to the identification of the two species.

Description

''Eulalia clavigera'' is a slender worm growing to a length of about . The prostomium (head) has a rounded triangular shape and is rather wider than it is long. It has a pair of palps and three antennae, the central one being located in front of the large eyes. The eversible proboscis is scattered with small conical papillae. There are four pairs of tentacular cirri on body segments one to four. The

parapodia In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; : parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed late ...

of the body segments bear large, paddle-shaped dorsal cirri, about twice as long as they are broad, while the ventral cirri are oval. This worm is bright green, sometimes with black spots on the underside of the base of the parapodia. ''E. clavigera'' is very similar in appearance to its close relative '' Eulalia viridis''. The chief differences between the two lie in the shape and size of the dorsal cirri.

Distribution and habitat

Before the 1990s, ''E. viridis'' was thought to have a wide range in the northeastern Atlantic including the waters around the United Kingdom, but morphological and biochemical studies led to the southern populations being recognised as a separate species ''E. clavigera'', part of a species complex with ''E. viridis''. This means that the distribution of ''E. clavigera'' is not well understood, with references in the literature referring to ''E viridis'' possibly being misapplied; however, ''E. clavigera'' is present around the coasts of Britain and southwards to France and the

Iberian Peninsula The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprisin ...

, and possibly into the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

. Its depth range is from the middle shore to the

sublittoral zone The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated ...

. It typically lives in crevices, under stones, among the holdfasts of large

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

s and among

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

s and

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

Biology

''Eulalia clavigera'' is predominantly a scavenger and feeds on dead or damaged invertebrates such as

barnacles Barnacles are arthropods of the subclass Cirripedia in the subphylum Crustacea. They are related to crabs and lobsters, with similar nauplius larvae. Barnacles are exclusively marine invertebrates; many species live in shallow and tidal water ...

and

mussels Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, whic ...

. Sexually mature individuals have been observed during July and August, while sexually mature ''E. viridis'' are generally seen between February and May.

References

{{Taxonbar, from=Q3650764 Phyllodocida Animals described in 1833 Taxa named by Henri Milne-Edwards Taxa named by Jean Victoire Audouin