''Amphianthus dohrnii'', the sea fan anemone, 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 ...

Hormathiidae. It occurs in the northeastern

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 ...

and

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 ...

and grows on sea fans.

Distribution and habitat

''Amphianthus dohrnii'' is native to the northeastern Atlantic Ocean and the western end of the Mediterranean Sea. It is scarce on the west coast of Scotland but more plentiful in southwestern Britain and in the western and southern parts of Ireland. It is present on the west coast of France and the westernmost parts of the Mediterranean at depths down to about . It tolerates both strong and weak currents and both plenty of, and little, wave action. It seems to grow exclusively on the stems of gorgonian corals, primarily the northern sea fan ('' Swiftia pallida'') in the north of its range, and the pink sea fan (''

Eunicella verrucosa ''Eunicella verrucosa'', the broad sea fan, pink sea fan or warty gorgonian, is a species of colonial Gorgonian "soft coral" in the family Gorgoniidae. It is native to the north-eastern Atlantic Ocean and the western Mediterranean Sea. Descript ...

'') in the south.

Description

''Amphianthus dohrnii'' is a small species, seldom exceeding in diameter, though the base, where it adheres to the substrate, may be up to long. It has about eighty short, tapering tentacles and is red, orange, pinkish or buff, with irregular translucent white markings.

Biology

Reproduction is mostly by basal laceration, a form of

asexual reproduction Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes. The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the fu ...

. The sea anemone crawls along a hard surface and pieces of tissue become detached and grow into new individuals. However, it is likely that

sexual reproduction Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...

sometimes takes place, as otherwise this species would be unlikely to be so widely dispersed. ''Amphianthus dohrnii'' was at one time common in both the Mediterranean and 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 ...

, but it seems now to be absent from the former and increasingly rare in the latter. In British waters, the sea fan ''

'' has declined, possibly being damaged by dredging or in association with higher sea temperatures, and the already rare ''Amphianthus dohrnii'' has become scarcer.

References

External links

* {{Taxonbar, from=Q5293991 Amphianthidae Animals described in 1878