Deep-water corals: An overview with special reference to diversity and distribution of deep-water scleractinian corals
2007; Rosenstiel School of Marine and Atmospheric Science; Volume: 81; Issue: 3 Linguagem: Inglês
ISSN
1553-6955
Autores Tópico(s)Marine Biology and Ecology Research
ResumoThe polyphyletic term coral is defined as those Cnidaria having continuous or discontinuous calcium carbonate or horn-like skeletal elements. So defined, the group consists of seven taxa (Scleractinia, Antipatharia, Octocorallia, Stylasteridae, and Milleporidae, two zoanthids, and three calcified hydractiniids) constituting about 5080 species, 66% of which occur in water deeper than 50 m, i.e., deep water as defined in this paper. Although the number of newly described species of deep-water scleractinian corals appears to be increasing at an exponential rate, it is suggested that this rate will plateau in the near future. The majority of azooxanthellate Scleractinia is solitary in form, firmly attached to a substrate, most abundant at 200-1000 m, and consist of caryophylliids. Literature helpful for the identification of deep-water Scleractinia is listed according to 16 geographic regions of the world. A species diversity contour map is presented for the azooxanthellate scleractinian species, showing centers of high diversity in the philippine region, the western Atlantic Antilles, and the northwest Indian Ocean, and is remarkably similar to high diversity regions for shallow-water zooxanthellate Scleractinia. As suggested for shallow-water corals, the cause for the high diversity of deep-water scleractinian diversity is thought to be the result of the availability of large contiguous stable substrate, in the case of deep-water corals at depths of 200-1000 m (the area effect), whereas regions of low biodiversity appear to be correlated with a shallow depth of the aragonite saturation horizon.
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