Scolymia
Scolymia, commonly called scoly coral, is a genus of large-polyp stony corals (Scleractinia). These animals are believed date back to the Miocene with three extant species present in the eastern Atlantic Ocean. Description. Unlike most other Scleractinia, "Scolymia" are solitary corals. Polyps can grow up to 10 cm in diameter. Morphology is diverse with both interspecific and intraspecific variation in shape. Polyps may be concave, convex, or flat depending on the species and environmental conditions. Species are generally distinguished based on differences in septa number, thickness, and orientation. Scoly corals range from brown to bright fluorescent greens, reds , and purples. Members of this genus are commonly found in reef aquariums because of their slow growth, however separation from other corals is necessary due to intense competition. The slow growth rate of these corals is not well understood, but researchers have proposed that cyanobacterial mats may inhibit their growth or even cause shrinkage. Ecology. Energy. "Scolymia" harness their energy mainly through a symbiotic relationship with zooxanthellate, a group of photosynthetic dinoflagellates. To a lesser degree, these corals can also feed heterotrophically using their tentacles to catch plankton drifting through the water at night. Habitat & Geographic Distribution. All "Scolymia" species  are located in the Atlantic Ocean along the east coast of the Americas between Florida, through the Caribbean sea and Gulf of Mexico, and as far south as Brazil. At higher latitudes, "Scolymia" tends to grow faster compared to at lower latitudes, likely as a result of annual mean temperature differences. Scoly corals are typically found at the base of a reef between 10-80 m deep where there are turbid waters with low-light conditions. "Scolymia" anchor in soft substrates where sediment continuously accumulates. They have adapted sediment-shifting abilities by growing upward on nearly-vertical surfaces in addition  to a mucus exterior that prevents sedimentation from above. This adaptation has allowed "Scolymia" to fill an ecological niche in which other corals are not able to survive. Predation. Scoly corals have a unique ability to avoid both disease and predation from coralivorous fishes. The reasons for this are still largely unknown, however, it is believed that their bold colors may deter predators. Conservation Status. According to the ICUN Red List, the conservation status of "Scolymia cubensis" and "Scolymia lacera" is Least Concern, and "Scolymia wellsii" is data deficient. While there are no specific known threats to "Scolymia", corals in  general are sensitive to rising temperatures brought on by climate change, resulting in coral bleaching. It is possible that "Scolymia", relatively deep habitat preference helps protect it from temperature-related damage. Behavior. Interspecific Competition. Some scoly corals are known to exhibit interspecific aggression by attacking both congeneric species and other corals, causing them to expel their zooxanthellates. Generally, "S. lacera" defeats and kills "S. cubensis". Reproduction. "Scolymia" reproduce sexually through broadcast spawning. Because of their lack of immune-recognition, it is possible for gametes from the same individual to fertilize each other, resulting in less genetic diversity. Fertilized planktonic larvae  drift through the current before settling on a reef bed. Intraspecific Fusion. When two or more "Scolymia cubensis" larvae settle near one another, they usually fuse together to form one complex coral with distinct genotypes. Taxonomy. Species. The World Register of Marine Species includes the following species in the genus: Other species were previously classified under "Scolymia" but have since been reclassified to distinct genera: