The walking anemone (''Preactis millardae''), also known as the hedgehog anemone or sock 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 ...
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 ...
s in the
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
Actiniaria
Sea anemones are a group of predatory marine invertebrates of the order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, ...
.
It is the
only member of its
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
, ''Preactis.''
Description
The walking anemone is an unusual looking anemone, which may grow to up to 6 cm in diameter and 30 cm in length. It has papillae covering its whole body column. Scarlet lines radiate outwards from the mouth and can be seen on the body between papillae. The background colour of the body is pale. Juveniles are pale or white in colour and have protruding rounded swellings on their bodies instead of papillae.
[Branch, G.M., Branch, M.L, Griffiths, C.L. and Beckley, L.E. 2010. ''Two Oceans: a guide to the marine life of southern Africa'' ]
Distribution
This anemone has only been found on both sides of the Cape Peninsula in South Africa. 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 this area. It has been found from 10 to 30 m underwater.
Ecology
This anemone 'walks' rather like a leech does, by creeping. It is usually found on vertical rock walls, although it may sometimes be found on sand patches. It is a voracious predator of the
multicoloured sea fan, ''Acabaria rubra'', and is often found eating these animals, which it consumes down to the skeletal support.
[Jones, Georgina. ''A field guide to the marine animals of the Cape Peninsula.'' SURG, Cape Town, 2008. ]
References
Preactiniidae
Animals described in 1984
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