Emplectonema neesii
Encyclopedia
Emplectonema neesii is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of ribbon worm in the phylum
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....

 Nemertea
Nemertea
Nemertea is a phylum of invertebrate animals also known as "ribbon worms" or "proboscis worms". Alternative names for the phylum have included Nemertini, Nemertinea and Rhynchocoela. Although most are less than long, one specimen has been estimated at , which would make it the longest animal ever...

. It is found on the middle and lower regions of the shore, under stones and in shingle and is common round the coasts of Britain and Ireland.

Description

Like other ribbon worms, this species is not divided into segments but is long, thin and contractile. It is usually ten to fifteen centimetres long but can extend to thirty centimetres. The head is bluntly pointed and has a slit at the front. It bears many eyes, usually in two groups, but these are hard to see because of the worm’s colouring and texture. There is an extensible proboscis above the mouth. The head is delineated by a pale streak where it joins the body. The dorsal surface of the body is rounded and brown with longitudinal streaks and a faint iridescence. The ventral surface is off white and flattened.

Distribution and habitat

E. neesii is restricted to the Atlantic, Irish Sea
Irish Sea
The Irish Sea separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel. Anglesey is the largest island within the Irish Sea, followed by the Isle of Man...

 and North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 coasts of Europe. It occurs from Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

 to the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...

. It is found in the littoral zone and at a depth of up to thirty metres. It is usually beneath stones and boulders, in rock crevices and fissures, among the holdfasts of Laminaria
Laminaria
Laminaria is a genus of 31 species of brown algae , all sharing the common name "kelp". This economically important genus is characterized by long, leathery laminae and relatively large size. Some species are referred to by the common name Devil's apron, due to their shape, or sea colander, due to...

, among the byssus threads of Mytilus colonies or on a variety of soft substrates including sand, silty-sand, shelly-gravel and shingle.

Biology

When disturbed, this worm tends to curl up, writhe and wriggle. Movement is performed by small waves of muscular contraction that flow along the body from tail to head. Several waves may occur simultaneously and the worm glides forward slowly and smoothly, the swellings running evenly along the body. It is carnivorous, being both a predator
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...

 and a scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...

.
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