Orbicella
| Orbicella | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Anthozoa |
| Subclass: | Hexacorallia |
| Order: | Scleractinia |
| Family: | Merulinidae |
| Genus: |
Orbicella Dana, 1846 |
| Species | |
|
|
|
Orbicella is a genus of stony corals in the Merulinidae family. The Orbicella species complex comprises three sister species, namely Orbicella faveolata, Orbicella annularis and Orbicella franksi, all of which are shallow-water, zooxanthellate species and are native to the tropical western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
These corals are ubiquitous in the Caribbean. Their similar colony morphologies misled scientists to historically lump them into a single species, Montastraea annularis, which included three morphotypes “bumpy”, “columnar” and “massive”. These growth forms were believed to arise as a response to abiotic factors (e.g., depth, light availability). This taxonomic classification was challenged by further ecological, reproductive, genetic, and morphologic evidence, which led to the re-description of three separate species, Montastraea faveolata (massive), M. annularis (columnar) and M. franksi (bumpy).
A taxonomic revision published in 2012 established that the “Montastraea annularis species complex” formed a separate clade now in the genus Orbicella with three species names (O. faveolata, O. annularis, O. franksi).O. annularis and O. faveolata are commonly called the Boulder Star coral and the Mountainous Star coral, respectively.
The colonies of these corals are massive and form dome-shaped mounds, with uneven surfaces and bulging projections. The corallites are small and closely packed. These corals are mostly some shade of light brown but sometimes have green oral discs.
Orbicella skeleton is made from CaCO3 in the crystal form of aragonite. The growth rate has been correlated with depth. In addition, the skeleton also contains Brucite [Mg(OH)2] in the interseptal spaces (microbialites). These brucite particles encrusts microbes growing inside the coral skeleton.
...
Wikipedia