Sagartia ichthystoma
Encyclopedia
Sagartia ichthystoma is a species
of sea anemone
in the family
Sagartiidae
, 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.
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.
. The two specimens first described by Philip Henry Gosse
in 1858 were found at Weymouth
and Torquay
, England
, the first one growing on an oyster
shell.
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
, armed with nematocysts, as a defence mechanism.
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...
Sagartiidae
Sagartiidae
Sagartiidae is a family of sea anemones.-Genera:Genera in the family include:* Actinothoe Fischer, 1889* Anthothoe* Bellactis* Botryon* Carcinactis* Cereus Oken, 1815* Choriactis* Gregoria* Habrosanthus...
, 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.
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 tentacleTentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
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 ChannelEnglish Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
. The two specimens first described by Philip Henry Gosse
Philip Henry Gosse
Philip Henry Gosse was an English naturalist and popularizer of natural science, virtually the inventor of the seawater aquarium, and a painstaking innovator in the study of marine biology...
in 1858 were found at Weymouth
Weymouth
Weymouth is a seaside town in Dorset, England, situated on a sheltered bay at the mouth of the River Wey on the English Channel coast. The town is south of Dorchester and north of the Isle of Portland. The town's population is 52,950 ....
and Torquay
Torquay
Torquay is a town in the unitary authority area of Torbay and ceremonial county of Devon, England. It lies south of Exeter along the A380 on the north of Torbay, north-east of Plymouth and adjoins the neighbouring town of Paignton on the west of the bay. Torquay’s population of 63,998 during the...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, the first one growing on an oyster
Oyster
The word oyster is used as a common name for a number of distinct groups of bivalve molluscs which live in marine or brackish habitats. The valves are highly calcified....
shell.
Biology
Like other sea anemones, S. ichthystoma is carnivorousCarnivore
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...
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
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...
, armed with nematocysts, as a defence mechanism.