Scolymia is a genus of usually solitary corals that are known for having single large polyps of highly fluorescent or beautifully marbled coloration. They are, however, prone to two major mistakes by reefkeepers. The first is with their pronunciation. They are pronounced Skah'-lee-MY'-ah. Most hobbyists and even vendors pronounce them Skoe-LEE-mee-ah. It sounds unusual, especially when one has been pronouncing it the wrong way for years, and may even sound odd after years of pronouncing it correctly. It still does to me!
The second major mistake with the genus is misidentification. They are easily confused with Cynarina lacrymalis or the deepwater Indophyllia macassarensis. The reason misidentification is so common is that in aquariums, the tissue of all these genera tend to be highly expanded and obscure the skeleton below. They can all be free-living, or appear to be free-living after collection, and with aquarium-sized specimens they can all be approximately the same size. In fact, many of the photos in this ReefSlides section are certainly Cynarina and with many of the other photos it is impossible to tell. Many hobbyists use coloration patterns to discern on their own that they have Scolymia rather than Cynarina. There is, however, an easy way to tell them apart. Cynarina have very large pointed teeth along their septa and these can be clearly seen in a specimen taken out of the water with the colony's tissue retracted. Alternately, one can carefully run one's finger along the septa and feel the large teeth below the tissue, even when expanded in the water. If the large teeth are present, the coral is almost certainly Cynarina. If rows of smaller ridge-like teeth are felt or seen, the specimen is probably Scolymia. The coloration of the corals is not a valid indicator for identification. The upper size limit may be an imperfect indicator, as can the shape under certain circumstances. Scolymia can occasionally be polycentric (having more than one mouth); their maximum size is generally larger (though most specimens may not be at their maximum size or ever reach their maximum size), and the shape of Scolymia is flattened to saucer-like but may tend to flatten near the margins or have a slightly contorted saucer shape. Scolymia are almost always attached to the reef but are occasionally free-living. Most specimens, therefore, should have an attachment scar on their underside where they were removed from the reef. Cynarina can be free-living or attached and are often free-living on soft bottoms. Indophyllia are almost always free-living and have very different septa, almost as though the sharp teeth of Cynarina were snipped off to make flat-topped teeth or filed to make them more rounded, and they are rarely colorful.
Scolymia occur in many reef environments but tend to be found in crevices or facing upwards under overhangs or sideways on vertical reef framework. This location would indicate that strong lighting environments are not preferred by the species. Although they occur in many reef habitats and though at least one of the two Indo-Pacific species is relatively common, they are common only because of their range of habitats. It is unusual to find "patches" or large areas dominated by this genus. They are typically found sporadically around the reef, occasionally clustered nearby to each other. In the aquarium, they make beautiful additions to a display with vividly colored tissue and dramatic tissue expansion. This is rather contrary to their field appearance as their tissues do not expand so dramatically as they do in captivity. Cynarina, on the other hand, expands greatly in the field and in aquariums. At night, healthy Scolymia are almost scary in the degree to which they extend feeding tentacles. They appear to almost invert their polyp, exposing a mass of short, fat, tapered feeding tentacles with extraordinary prey capture abilities. They are almost unrecognizable from their appearance during the day.
In general, Scolymia are easy to keep alive in captivity as they do not have requirements for strong light or water flow, and may be adverse to it. This is fortunate since they are not abundant on reefs and may be prone to local overcollection. Propagation of the species is relatively easy using a wet saw (tile saw) to cut the polyps in halves or quarters and flushing the cut fragments well before returning them to the tank. Cynarina can be propagated by simply nipping off bits of the septa (Toonen, pers. comm.), and Scolymia may be similarly possible to propagate using small snips of tissue and skeleton, but to my knowledge this has not been tried or utilized as a form of regular propagation to date.
Text by Eric Borneman.
to Gary Majchrzak for his assistance with this project.
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