''Sagartia elegans'', the elegant anemone, is a species of

sea anemone Sea anemones ( ) are a group of predation, predatory marine invertebrates constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

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 ...

Sagartiidae. It is found in coastal areas of northwest Europe at depths down to 50 metres.

Description

The base of ''S. elegans'' is wider than the column and may reach in diameter. The base is usually anchored to the substrate but can be used as a foot for locomotion. It often has a ragged outline due to fragmentation having occurred. The column is soft and fleshy and varies in shape, even in one individual, from squat to cylindrical or trumpet shaped, and can grow up to tall. The lower part of the column is somewhat corrugated and there are a number of pale coloured suckers on the upper part to which grit or shell fragments may adhere occasionally. The disc is saucer-shaped with an undulating margin and there are up to 200

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s arranged irregularly, often arching over the edge. These are mostly about the same length but occasionally there is a much longer one among them. This may be used, as it is in some other sea anemone species, to prevent competing organisms from settling and occupying space nearby. When it is disturbed, a large number of white threads known as

acontia ''Acontia'' is a genus of moths of the family Noctuidae. The genus was named by Ferdinand Ochsenheimer in 1816. ''Eusceptis'', ''Pseudalypia'' and ''Spragueia'' are sometimes included in the present genus, but here they are tentatively treated ...

are discharged from cells on the column Family Sagartiadie

Philip Henry Gosse Philip Henry Gosse (; 6 April 1810 – 23 August 1888), known to his friends as Henry, was an English natural history, naturalist and populariser of natural science, prolific author, "Father of the Aquarium", scientific illustrator, lecturer, e ...

. A history of the British sea-anemones and corals. Retrieved 2011-09-06. and from the mouth.The occurrence of ''Sagartia elegans'' (Dalyell, 1848) (Anthozoa: Actiniaria) in the Netherlands
Retrieved 2011-09-06. These are for defensive purposes and are armed with

nematocyst A cnidocyte (also known as a cnidoblast) is a type of cell containing a large secretory organelle called a ''cnidocyst'', that can deliver a sting to other organisms as a way to capture prey and defend against predators. A cnidocyte explosively ...

s. When not submerged, ''S. elegans'' hangs in a limp fashion. It sometimes partially protrudes the lining of its

coelom The coelom (or celom) is the main body cavity in many animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, i ...

through its mouth. If disturbed it will retract more completely, disappearing from view if it is lodged in a crevice.''Sagartia elegans''
Marine Species Identification Portal. Retrieved 2011-09-06. There are a number of differently coloured varieties: * ''Var. miniata'': Disc variously coloured and patterned with similar coloured tentacles, often banded. * ''Var. rosea'': Disc variously coloured and patterned and tentacles rose red. * ''Var. aurantiaca'': Disc grey and tentacles dull orange. * ''Var. nivea'': Disc and tentacles translucent white. * ''Var. venusta'': Disc orange or buff and tentacles white.

Distribution

''S. elegans'' is found in coastal areas of the northeast

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

from

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

and the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

south to 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 ...

. It is common round the coasts of the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

where the form ''var. miniata'' is the most abundant. In the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

the population fluctuates widely, with decreases occurring after severe winters with cold sea temperatures.

Habitat

''S. elegans'' is found from the mid-shore down to a depth of about 50 metres. Its base is often in holes and cracks in the rock and it is also found under stones, beneath overhangs, in rock pools and caves. It also favours brightly lit rock walls with fast moving currents.''Sagartia elegans''
British Marine Life. Retrieved 2011-09-06.

Biology

''S. elegans'' is an

omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

scavenger Scavengers are animals that consume Corpse decomposition, dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a he ...

and

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

. Most of its nourishment comes from the ingestion of small

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s which are caught by the tentacles and thrust into the mouth. The undigested fragments are later expelled through the mouth. ''S. elegans'' often reproduces asexually by fragmentation, also known as basal laceration. As it crawls across a rock surface, pieces of its base become detached and grow into new individuals. This gives rise to groups of sea anemones in close proximity to each other which have identical colourations.

Ecology

Other organisms found in the same habitat include the breadcrumb

sponge Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...

Halichondria panicea ''Halichondria panicea'', commonly known as the breadcrumb sponge, is a species of sea sponge belonging to the family Halichondriidae. It is an abundant sponge of coastal areas of the North Atlantic and the Mediterranean Sea ranging from the inte ...

and the

soft coral Alcyonacea is the old scientific order name for the informal group known as "soft corals". It is now an unaccepted name for class Octocorallia. It became deprecated . The following text should be considered a historical, outdated way of treatin ...

Alcyonium digitatum ''Alcyonium digitatum'' or dead man's fingers is a species of soft coral in the family Alcyoniidae. It is found around the coasts of the northern Atlantic Ocean and other temperate waters such as the South Pacific. Description Dead man's fingers ...

Venom

Sponge gatherers in the Mediterranean Sea come in contact with these sea anemones as they collect sponges. This causes a burning and itching sensation followed by

erythema Erythema (, ) is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology inc ...

and blisters, the symptoms of "sponge fishermen's disease". Individuals may also experience nausea, vomiting, fever, muscle spasms and collapse.

References

External links

* {{Taxonbar, from=Q2318033 Sagartiidae Cnidarians of the Atlantic Ocean Fauna of the Mediterranean Sea Animals described in 1848