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The Alcyonacea, or soft corals, are an order of corals which do not produce calcium carbonate skeletons. Soft corals contain minute, spiny skeletal elements called sclerites, useful in species identification. Sclerites give these corals some degree of support and give their flesh a spiky, grainy texture that deters predators. In the past soft corals were thought to be unable to lay new foundations for future corals, but recent findings suggest that colonies of the leather-coral genus ''Sinularia'' are able to cement sclerites and consolidate them at their base into alcyonarian spiculite,〔Kenji Konishi, "Alcyonarian spiculite: the limestone of soft corals", 1981; M.-S. Jeng, H.-D. Huang, C.-F. Dai, Y.-C. Hsiao and Y. Benayahu. (15 May 2011), "Sclerite calcification and reef-building in the fleshy octocoral genus Sinularia (Octocorallia: Alcyonacea)", ''Earth and Environmental Science'', Coral Reefs .〕 thus making them reef builders. Unlike stony corals, most soft corals thrive in nutrient-rich waters with less intense light. Almost all utilize symbiotic photosynthesizing zooxanthella as a major energy source. However, most will readily eat any free floating food, such as zooplankton, out of the water column. They are integral members of the reef ecosystem and provide habitat for fish, snails, algae and a diversity of other marine species. Many soft corals are easily collected in the wild for the reef aquarium hobby, as small cuttings are less prone to infection or damage during shipping than stony corals. Nevertheless, home-grown specimens tend to be more adaptable to aquarium life and help conserve wild reefs. Soft corals grow quickly in captivity and are easily divided into new individuals, and so those grown via aquaculture are often hardier and less expensive than imported corals from the wild. The most common examples of this are various species of ''Actinodiscus'', especially common red mushroom coral. ==Suborders and families== The World Register of Marine Species lists the following suborders and families:〔 *Suborder Alcyoniina * *Family Alcyoniidae * *Family Nephtheidae * *Family Nidaliidae * *Family Paralcyoniidae * *Family Xeniidae *Suborder Calcaxonia * *Family Chrysogorgiidae * *Family Dendrobrachiidae * *Family Ellisellidae * *Family Ifalukellidae * *Family Isididae * *Family Primnoidae *Suborder Holaxonia * *Family Acanthogorgiidae * *Family Gorgoniidae * *Family Keroeididae * *Family Plexauridae *Suborder Protoalcyonaria * *Family Taiaroidae *Suborder Scleraxonia * *Family Anthothelidae * *Family Briareidae * *Family Coralliidae * *Family Melithaeidae * *Family Paragorgiidae * *Family Parisididae * *Family Subergorgiidae *Suborder Stolonifera * *Family Acrossotidae * *Family Clavulariidae * *Family Coelogorgiidae * *Family Cornulariidae * *Family Pseudogorgiidae * *Family Tubiporidae *Unassigned * *Family Acanthoaxiidae * *Family Haimeidae * *Family Viguieriotidae File: 1898_aquaimages.jpg |A close-up of an alcyonacean showing individual polyps File:soft2.jpg|''Dendronephthya klunzingeri'' File:Expl2319 - Flickr - NOAA Photo Library.jpg|Field of Callogorgia sp. with ophiuroid symbiont 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alcyonacea」の詳細全文を読む スポンサード リンク
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