''Stylaster nobilis'', the noble coral, is a branching colonial hydroid 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 ...

Stylasteridae Stylasteridae is a family of hydrozoans. Genera According to the World Register of Marine Species, the following genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as ...

Description

Noble corals are pink or orange and tree-like with paler tips to the colony's branches. The calcareous colonies may grow to over 25 cm in total height, while individual polyps are 0.1 cm in diameter.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'' There is no free medusa stage. The polyps project from star-shaped cavities in the rigid calcareous skeleton. Growth occurs at the tips and on the outside surface, which gradually thickens and which may show concentric rings in section.

Colour and shape variation

File:Noble corals at Mushroom Pinnacle DSC06533.jpg, Two colour morphs at Oudekraal, on the Cape Peninsula File:Noble coral at Vulcan Rock DSC00860.jpg, Occasionally ''S. nobilis'' will develop a more encrusting structure File:Two colour morphs of noble coral at Middle Bank P2277208.JPG, Specimens from about 35m depth in the Tsitsikamma Marine Protected Area File:Noble coral at Klein Tafelberg DSC00353.JPG, A densely packed structure is also possible File:Stylaster nobilis P3164683.JPG, A stocky morph can be found in a few places File:Stylaster nobilis P3164685.JPG, The colouration may occasionally be mottled File:Stylaster nobilis PC132911.JPG, In some areas there is significantly less branching File:Stylaster nobilis PC132935.JPG, In some cases there may be no branching at all

Distribution

This colonial animal is found only off the South African coast from the Atlantic Coast of the Cape Peninsula to Port Elizabeth in 5-100m of water. 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 els ...

to this region.

Ecology

Noble corals feed on plankton and resemble

hard coral Scleractinia, also called stony corals or hard corals, are marine animals in the phylum Cnidaria that build themselves a hard skeleton. The individual animals are known as polyps and have a cylindrical body crowned by an oral disc in which a mo ...

s. They occur in cool temperate waters usually in caves and under overhangs. They are very slow-growing: large colonies may be over 100 years old. A permit is required to collect these animals.

Synonyms

The following species are considered synonyms of ''Stylaster nobilis'': *''Allopora explanata'' Kent, 1871 *''Allopora nobilis'' Kent, 1871 *''Allopora ochracea'' Qulech, 1884

References

{{Taxonbar, from=Q2844836 Stylasteridae Animals described in 1921