Ivell's sea anemone (''Edwardsia ivelli'') 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

Edwardsiidae Edwardsiidae is a family of sea anemones. Edwardsiids have long thin bodies and live buried in sediments or in holes or crevices in rock. Genera The following genera are recognized within the family Edwardsiidae. * '' Drillactis'' Verrill, 1922 ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to a single location, Widewater Lagoon in

West Sussex West Sussex is a county in South East England on the English Channel coast. The ceremonial county comprises the shire districts of Adur, Arun, Chichester, Horsham, and Mid Sussex, and the boroughs of Crawley and Worthing. Covering an ar ...

, England, where it was first discovered by Richard Ivell. It has been listed as

Data Deficient A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessaril ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

since 1996.

Description

Ivell's sea anemone is a tiny, worm-like anemone up to long and diameter; the column is similar to other ''

Edwardsia ''Edwardsia'' is a genus of sea anemones, the type of the family Edwardsiidae. They have eight mesenteries and live in tubes in the sand. The name, in New Latin, commemorates the French zoologist Henri Milne-Edwards. The genus contains the fo ...

'' spp. There are twelve transparent tentacles, arranged in two cycles, nine tentacles in the outer cycle and three in the inner cycle. In life the tentacles of the outer cycle are held flat on the substrate, the three of the inner cycle more or less vertical, often curled over the mouth. Each tentacle has a few transverse bars of pale cream occasionally forming complete rings.

Distribution

It is endemic to England known from only one site, Widewater Lagoon in West Sussex, the type locality. Searches in recent years have failed to find any specimens and the species is considered

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

by some conservationists

Habitat

Burrows in soft mud in saline lagoons or sheltered creeks, it is a tiny species and easily overlooked unless deliberately sought.

Similar species

Although the type of locality inhabited by this species is not often searched by divers such places are well worth investigating. This species and '' Nematostella vectensis'' are probably the only British

Anthozoa Anthozoa is a subphylum of marine invertebrates which includes the sea anemones, Scleractinia, stony corals and Alcyonacea, soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plank ...

ns which can be considered endangered species through habitat destruction and pollution. Ivell's sea anemone was discovered by Professor Richard Ivell, hence the species' name.Manuel, R.L. (1975). A new sea anemone from a brackish lagoon in Sussex, ''Edwardsia ivelli'', sp. nov. Journal of Natural History, 9, 705-711.

References

{{Taxonbar, from=Q2124204 Edwardsia Endemic fauna of England Cnidarians of the Atlantic Ocean Anthozoa of Europe Marine fauna of Europe Environment of West Sussex Animals described in 1975 1975 in England Taxonomy articles created by Polbot