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

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

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Sagartiidae Sagartiidae is a family of sea anemones. Genera Genera in the family include: * '' Actinothoe'' Fischer, 1889 * ''Anthothoe'' Carlgren, 1938 * '' Artemidactis'' Stephenson, 1918 * '' Botryon'' Carlgren & Hedgepeth, 1952 * '' Cancrisocia'' * '' ...

. 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 Fragmentation or fragmented may refer to: Computers * Fragmentation (computing), a phenomenon of computer storage * File system fragmentation, the tendency of a file system to lay out the contents of files non-continuously * Fragmented distributi ...

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 FRS (; 6 April 1810 – 23 August 1888), known to his friends as Henry, was an English naturalist and populariser of natural science, an early improver of the seawater aquarium, and a painstaking innovator in the study of ma ...

. 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 or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this ce ...

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 most 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, it r ...

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 oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

from

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...

and the

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

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 north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

. It is common round the coasts of the

British Isles The British Isles are a group of islands in the 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 and Outer Hebrides, the Northern Isles, ...

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

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

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 has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...

scavenger Scavengers are animals that consume 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 herbivorous feeding b ...

and

predator 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 ...

. Most of its nourishment comes from the ingestion of small

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

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

, 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, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

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

and the

soft coral Alcyonacea, or soft corals, are an order of corals. In addition to the fleshy soft corals, the order Alcyonacea now contains all species previously known as "gorgonian corals", that produce a more or less hard skeleton, though quite different f ...

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 (from the Greek , meaning red) 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 assoc ...

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