''Swiftia pallida'' 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 ...
of gorgonian-type
octocoral
Octocorallia (also known as Alcyonaria) is a class of Anthozoa comprising around 3,000 species of water-based organisms formed of colonial polyps with 8-fold symmetry. It includes the blue coral, soft corals, sea pens, and gorgonians (sea fan ...
in the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Plexauridae
Plexauridae is a family of marine colonial octocorals in the phylum Cnidaria. Members of this family are found in shallow tropical and subtropical seas. Many species contain symbiotic photosynthetic protists called zooxanthellae.
Characteristi ...
sometimes known as the northern sea fan. At one time it was considered to be a subspecies of ''
Swiftia rosea''.
[
]
Description
''Swiftia pallida'' usually has a single main stem arising from a narrow base and is sparsely branched. Its normal height is about but it can grow to . The polyps are mostly arranged alternately, but somewhat irregularly, on either side of the stem and branches. Each polyp is supported by eight spindle-shaped sclerite
A sclerite (Greek , ', meaning " hard") is a hardened body part. In various branches of biology the term is applied to various structures, but not as a rule to vertebrate anatomical features such as bones and teeth. Instead it refers most commonly ...
s, spiny skeletal elements, which run from the stem or branch to the bases of the eight tentacles. In the north of its range, this species is usually white or pale grey, but in the Mediterranean it may be pink or red.[ This sea fan resembles pale varieties of the more common ''Swiftia rosea'' but is less bushy with fewer branches.]
Distribution and habitat
''Swiftia pallida'' is native to the northeast 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 ...
, the 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 ...
,[ the Bay of Biscay, Madeira and ]Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria t ...
. In the northern part of this range its depth range is between but in the southern part it occurs in very deep water,[ This sea fan also occurs in deep water on the continental shelf off the Atlantic coast of North America.][ or on large pebbles lying on a silty or broken shell seabed.][
]
Ecology
The sea fan anemone (''Amphianthus dohrnii
''Amphianthus dohrnii'', the sea fan anemone, is a species of sea anemone in the family Hormathiidae. It occurs in the northeastern Atlantic Ocean and Mediterranean Sea and grows on sea fans.
Distribution and habitat
''Amphianthus dohrnii'' is ...
'') seems to live exclusively on sea fans. In the northern part of its range it is associated with ''Swiftia pallida'', and in the southern part with the pink sea fan ('' Eunicella verrucosa'').[
]
References
{{Taxonbar, from=Q3273672
Plexauridae
Animals described in 1970