''Melithaea ochracea'' is a

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

colonial Colonial or The Colonial may refer to: * Colonial, of, relating to, or characteristic of a colony or colony (biology) Architecture * American colonial architecture * French Colonial * Spanish Colonial architecture Automobiles * Colonial (1920 a ...

soft

coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secre ...

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 ...

Melithaeidae ''Melithaeidae'' is a family of corals in the suborder Scleraxonia. Members of the family are commonly known as sea fans and are found on reefs in the tropical regions of the Indo-Pacific.coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. C ...

s in the South China Sea. It is used in the jewellery industry under the name red spongy coral.

Description

Colonies of ''Melithaea ochracea'' are arborescent and usually grow to about long although much larger specimens can be found. They grow in one plane and have a branching, fan-shaped structure. The main skeletal stalk and branches are jointed, with swellings at the larger joints. The internodes are composed of hard, calcareous material while the joints are flexible and made of a horny material. The skeleton is covered by a flexible membrane, the

mesoglea Mesoglea refers to the extracellular matrix found in cnidarians like coral or jellyfish that functions as a hydrostatic skeleton. It is related to but distinct from mesohyl, which generally refers to extracellular material found in sponges. Desc ...

, which contains minute calcareous spicules or sclerites. The identity of these is important for distinguishing between different closely related species. In ''Melithaea ochracea'', they include capstans, double discs, disc-spindles and unilaterally spinose spindles, plain spindles, clubs and anthocodial sclerites. Three sides of the branches are densely covered in calyces, dome shaped perforated structures from which the polyps protrude. Colonies vary in colour but tend to be shades of yellow, orange, red and white, sometimes with contrasting colours for the calyces and polyps. It is an azooxanthellate coral and does not contain symbiotic unicellular algae in its tissues. In

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...

, it sometimes grows close to the low tide mark at depths of under where colonies grow larger than deeper water specimens and mostly have yellow branches and red calyces. At greater depths, down to , the colonies are smaller and have different colour combinations.

Distribution and habitat

''Melithaea ochracea'' grows on shallow reefs in the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phil ...

between

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northe ...

and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. Its range also includes Singapore and

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

. In Taiwan, it is the most widespread gorgonian coral and is found on the higher parts of reef fronts where its numerous small polyps can feed at water flow rates varying from per second.Aquarium plants
Experts Guide To Saltwater Aquariums. Retrieved 2012-02-24.

Uses

''Melithaea ochracea'' can be used in

reef aquaria A reef aquarium or reef tank is a marine aquarium that prominently displays live corals and other marine invertebrates as well as fish that play a role in maintaining the tropical coral reef environment. A reef aquarium requires appropriately ...

to add interest to fish tanks and requires a moderate flow of water to allow the polyps to feed on non-evasive zooplankton and probably also phytoplankton. ''Melithaea ochracea'' is used in the jewellery industry where it is known as sponge coral because of the porous nature of the structure. Bright orange-red specimens are considered most desirable but variegated specimens, with yellow or orange streaks, are also sought after. Most of the sponge coral on the market has been stabilised by being filled with resin or polymer and polished. It is also sometimes dyed or crushed, mixed with epoxy resin and formed into the desired shape. It can be carved and is popular because it is relatively cheap. Natural, unenhanced coral is more expensive than its treated counterpart but it is difficult to find sufficient attractive rough material on the market. The coral measures 3.5 on the

Mohs scale of mineral hardness The Mohs scale of mineral hardness () is a Qualitative property, qualitative ordinal scale, from 1 to 10, characterizing scratch hardness, scratch resistance of various minerals through the ability of harder material to scratch softer material. ...

so besides being easy to work, it is also easy to damage. It should not be worn next to the skin because it may become stained.Sponge coral
JCK. Retrieved 2012-02-22. It is harvested in the South China Sea between Taiwan and Indonesia and is sometimes farmed. It grows much more quickly than the traditional hard corals ('' Crallium spp.'') that are used in jewellery and its harvesting is believed to be sustainable.The Story of Coral
Kashgar. Retrieved 2012-02-22.

References

{{Taxonbar, from=Q2690404 Melithaeidae Animals described in 1758 Taxa named by Carl Linnaeus