Metridium farcimen
Encyclopedia
Metridium farcimen is a species
of sea anemone
in the family
Metridiidae
. It is commonly known as the giant plumose anemone or white-plumed anemone. It is found on the western seaboard of the United States and Canada and in deep water sites especially where the water is slow moving.
s of Metridium giganteum. Of these, Actinia farcimen was the name first published. It is, however, a junior homonym so the valid name for the species is Metridium farcimen; (Brandt, 1835). The World Register of Marine Species attributes the name Metridium farcimen to (Tilesius, 1809) and gives Isometridium rickettsi; Carlgren, 1949, as the only synonym.
. These are openings through which thread-like nematocysts from inside the body wall can protrude. There are no tubercles and the column is topped by a parapet. The oral disc is lobed and deeply convoluted at the edge and bears well over 100 fine, short, tapering tentacles. The colour is generally opaque white, but orange, salmon and brown specimens sometimes occur. Large specimens have been seen to have long, thick, fighting tentacles, used to drive away other anemones trying to settle too close. In large colonies
that all emanate from one individual by cloning
, individuals on the edge of the colony may have several of these fighting tentacles on their lips which they use to repel other, non-clonal anemones. Metridium farcimen might be confused with Metridium senile
which occupies the same habitat and has a similar colour and form, but that species seldom exceeds 10 cm (4 in) in height, has fewer than 100 tentacles and has an unlobed oral disc.
southwards to California
. It is at its most common in Puget Sound
and around Vancouver Island
. It is found in the sublittoral zone
on rocks, mollusc shell
s, pilings, docks and other man-made structures and even in polluted waters. It is also found at great depths, near hydrothermal vent
s, cold water seeps
and decomposing whale carcases on the seabed
.
. It captures small invertebrates, zooplankton
and other food particles with the nematocysts on its tentacles and thrusts them into the mouth in the centre of its oral disc. Large anemones have few predators but smaller specimens are eaten by the starfish, Pisaster
spp., and by various nudibranch
s. The starfish, Dermasterias imbricata
, has been observed feeding on larger anemones in Puget Sound.
Reproduction takes place with the liberation of eggs and sperm from the gonads embedded in the body wall which are then ejected through the mouth. Fertilised eggs develop into planula
larva
e. After several moults, these settle and metamorphose
into polyp
s. Asexual reproduction
can also take place by laceration. When the anemone crawls around it may leave bits of tissue behind which can develop into new individuals.
Metridium farcimen is a long lived species. A plumose anemone in this genus is reported to have lived for nearly 100 years in an aquarium
, and even after that time, the cause of death was equipment failure rather than old age.
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 sea anemone
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Metridiidae
Metridiidae
Metridiidae is a family of sea anemones in the order Actiniaria.-Characteristics:Members of the family Metridiidae are characterised by having a mesogloeal sphincter muscle and by the mesenterial arrangement, with the mesenteries not being divided into macronemes and microcnemes...
. It is commonly known as the giant plumose anemone or white-plumed anemone. It is found on the western seaboard of the United States and Canada and in deep water sites especially where the water is slow moving.
Taxonomy
In 1990, Fautin et al. examined the validity of the name Metridium giganteum. A further study in 2000 concluded that Actinia pripaus; Tilesius, 1809, Actinia farcimen; Brandt, 1835, and Isometridium rickettsi; Carlgren, 1949 were all synonymSynonym
Synonyms are different words with almost identical or similar meanings. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy. The word comes from Ancient Greek syn and onoma . The words car and automobile are synonyms...
s of Metridium giganteum. Of these, Actinia farcimen was the name first published. It is, however, a junior homonym so the valid name for the species is Metridium farcimen; (Brandt, 1835). The World Register of Marine Species attributes the name Metridium farcimen to (Tilesius, 1809) and gives Isometridium rickettsi; Carlgren, 1949, as the only synonym.
Description
Metridium farcimen is a large sea anemone, occasionally reaching a height of one metre (39 in) when fully extended. More usually it is 50 cm (20 in) or less in height but is very variable in shape. It can retract its tentacles and form a ball up to 25 cm (10 in) in diameter. The column is slender, smooth and studded with acontiaAcontia
Acontia is a genus of moths of the Noctuidae family.-Species:* Acontia albida * Acontia albinigra Warren, 1913* Acontia antecedens Walker, 1869* Acontia antica Walker, 1862* Acontia apatelia Swinhoe, 1907...
. These are openings through which thread-like nematocysts from inside the body wall can protrude. There are no tubercles and the column is topped by a parapet. The oral disc is lobed and deeply convoluted at the edge and bears well over 100 fine, short, tapering tentacles. The colour is generally opaque white, but orange, salmon and brown specimens sometimes occur. Large specimens have been seen to have long, thick, fighting tentacles, used to drive away other anemones trying to settle too close. In large colonies
Colony (biology)
In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies...
that all emanate from one individual by cloning
Clone
-Biological:* Clone—In biology and agriculture, any organism whose genetic information is identical to that of a parent organism from which it was created; natural reproductive processes producing clones include parthenogenesis and apomixis...
, individuals on the edge of the colony may have several of these fighting tentacles on their lips which they use to repel other, non-clonal anemones. Metridium farcimen might be confused with Metridium senile
Metridium senile
Metridium senile, common name the plumose anemone or frilled anemone, is a species of sea anemone in the family Metridiidae. It is found in the seas off northwest Europe and the east and west coasts of North America.-Description:...
which occupies the same habitat and has a similar colour and form, but that species seldom exceeds 10 cm (4 in) in height, has fewer than 100 tentacles and has an unlobed oral disc.
Distribution
Metridium farcimen is found on the western seaboard of the United States and Canada. Its range extends from AlaskaAlaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
southwards to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. It is at its most common in Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...
and around Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
. It is found in the sublittoral zone
Neritic zone
The neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone, is the part of the ocean extending from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters...
on rocks, mollusc shell
Mollusc shell
The mollusc shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which includes snails, clams, tusk shells, and several other classes...
s, pilings, docks and other man-made structures and even in polluted waters. It is also found at great depths, near hydrothermal vent
Hydrothermal vent
A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both...
s, cold water seeps
Cold seep
A cold seep is an area of the ocean floor where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs, often in the form of a brine pool...
and decomposing whale carcases on the seabed
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
.
Biology
Metridium farcimen is a carnivoreCarnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
. It captures small invertebrates, zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
and other food particles with the nematocysts on its tentacles and thrusts them into the mouth in the centre of its oral disc. Large anemones have few predators but smaller specimens are eaten by the starfish, Pisaster
Pisaster
Pisaster is a genus of Pacific sea stars that includes three species, P. brevispinus, P. giganteus, and P. ochraceus. Their range extends along the Pacific coast from Alaska to southern California in the intertidal zone. Pisasters can reach up to in width and typically have five arms...
spp., and by various nudibranch
Nudibranch
A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...
s. The starfish, Dermasterias imbricata
Dermasterias imbricata
Dermasterias imbricata or the leather star is a starfish in the family Asteropseidae. It is found at depths of up to one hundred metres off the western seaboard of North America.-Description:...
, has been observed feeding on larger anemones in Puget Sound.
Reproduction takes place with the liberation of eggs and sperm from the gonads embedded in the body wall which are then ejected through the mouth. Fertilised eggs develop into planula
Planula
A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species. The planula forms from the fertilized egg of a medusa, as the case in scyphozoans and some hydrozoans, or from a polyp, as in the case of anthozoans...
larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e. After several moults, these settle and metamorphose
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
into polyp
Polyp
A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are approximately cylindrical in shape and elongated at the axis of the body...
s. Asexual reproduction
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
can also take place by laceration. When the anemone crawls around it may leave bits of tissue behind which can develop into new individuals.
Metridium farcimen is a long lived species. A plumose anemone in this genus is reported to have lived for nearly 100 years in an aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
, and even after that time, the cause of death was equipment failure rather than old age.