''Sagartia ichthystoma'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

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'' * '' ...

, also known as the fish-mouth anemone. The species name refers to the short pointed tentacles round the edge of the disc which resemble the sharp teeth of certain fish.''Sagartia ichthystoma''

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 2011-09-04.

Description

The base of ''S. ichthystoma'' is usually found adhering to rocks or shells and is no wider than the column. This is cylindrical, purplish-red, and about as long as it is wide, covered with corrugations but without warts. It can retract into a nipple-shaped button. The disc is fawn and is slightly concave with an enlarged margin and clearly marked, black radii. The

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 are translucent white with black and grey bands. They are small and conical and set in three rows which are positioned very close to the margin. The mouth is on a raised mound and the scarlet lips are wrinkled and swollen.

Distribution and habitat

''S. ichthystoma'' is found in the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

. The two specimens first described by

in 1858 were found at Weymouth and

Torquay Torquay ( ) is a seaside town in Devon, England, part of the unitary authority area of Torbay. It lies south of the county town of Exeter and east-north-east of Plymouth, on the north of Tor Bay, adjoining the neighbouring town of Paignton ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

, the first one growing on an

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...

shell.

Biology

Like other sea anemones, ''S. ichthystoma'' is

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

and feeds on small invertebrates which it catches with its tentacles and channels into its mouth. If disturbed, it can emit sticky threads called

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 ...

, 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, as a defence mechanism.

References

{{Taxonbar, from=Q3326576 Sagartiidae Animals described in 1858 Taxa named by Philip Henry Gosse Cnidarians of the Atlantic Ocean