''Eulalia viridis'' is a species of bright-green

polychaete 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 ...

worm in the family

Phyllodocidae Phyllodocidae is a 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 dorsal cirri. The head ...

. It can range from in length and is usually found in shallow north Atlantic water under rocks or in

mussel 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 ...

beds.Hayward, P.J.; Ryland, J.S. (1995). Handbook of the Marine Fauna of North-West Europe. Oxford University Press. New York.

Description

''E. viridis'' is a dorsally flattened, slender worm with up to 200 segments. It grows to a length of and is mid-green or bright green in colour. The head bears five antennae, two eyes and four pairs of tentacular cirri; the eversible proboscis is cylindrical and dotted with rounded papillae. Each body segment has a pair of

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

, and the

cirri Giovanni Battista Cirri (1 October 1724 – 11 June 1808) was an Italian cellist and composer in the 18th century. Biography Cirri was born in Forlì in the Emilia-Romagna Region of Italy. He had his first musical training with his brother ...

on these are long, thin and pointed. They project outwards, forming a fringe down each side of the body.

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 ''

Eulalia clavigera ''Eulalia clavigera'' is a species of polychaete worm in the family Phyllodocidae, native to the coasts around Britain, through Western France, and to the Iberian Peninsula. It closely resembles ''Eulalia viridis'', and there has been confusion ...

'', part of a species complex with ''E. viridis''. As now recognised, ''E. viridis'' is native to the northeastern Atlantic Ocean where it is found in the waters off Norway, Sweden, Denmark and Germany, as well as the

Faroe Islands The Faroe Islands ( ), or simply the Faroes ( fo, Føroyar ; da, Færøerne ), are a North Atlantic archipelago, island group and an autonomous territory of the Danish Realm, Kingdom of Denmark. They are located north-northwest of Scotlan ...

, Iceland and

Disko Island Disko Island ( kl, Qeqertarsuaq, da, Diskoøen) is a large island in Baffin Bay, off the west coast of Greenland. It has an area of ,mussel 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 ...

beds.

Biology

Although many worms in this family are

predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

and actively hunt prey, ''E. viridis'' seems to be more selective in its diet, and researchers found that it only consumed moribund or dead animal tissue. Breeding does not take place until the worms are at least two years old, and they are not thought to form swarms as do some other related species. The greenish gelatinous egg mass is attached to

brown algae Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate an ...

, but some populations seem not to have egg masses. The larvae pass through one or two

trochophore A trochophore (; also spelled trocophore) is a type of free-swimming planktonic marine larva with several bands of cilia. By moving their cilia rapidly, they make a water eddy, to control their movement, and to bring their food closer, to captur ...

stages and two other stages before settling on the sea bed as a five- to nine-segmented larva, after up to nine weeks.

References

{{Taxonbar, from=Q224605 Phyllodocida Animals described in 1767 Taxa named by Carl Linnaeus