Easy Stony (Hard) Corals
I would like to mention some of the stony (hard) corals that are among the easiest to keep for those starting their first reef aquarium.
J. Charles Delbeek, M.Sc.
In the last issue, we looked at some of the hardier soft corals that can be kept by someone who is just getting started in the reef aquarium hobby. In this column, I would like to mention some of the stony (hard) corals that are among the easiest to keep for those starting their first reef aquarium.
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It is not difficult to find high-quality coral frags. Look for events in your area, such as frag swaps, where coral frags such as these may be available.
Before I go any further, I do want to point out one important element. Many of the corals I mentioned last month and this month are available as propagated specimens. These could be from a coral farm in the southern or western Pacific, from commercial operations in your home country or from local hobbyists. In fact, one of the best sources is the numerous frag swaps that occur around the country each year. Here you can find a wide range of quality coral fragments, including many of the easier ones. I attended the Bay Area Reefers Club’s annual coral frag swap last year. They were offering several high-demand specimens and literally giving away cuttings of easy-to-keep corals to people who were just getting into the hobby. I suggest searching online for such events in your area. The days of only being able to get corals from wild sources are over, and the sooner this becomes common knowledge to the general public, the less likely we will have laws that will prevent us from keeping certain coral species.
Stony corals are usually divided into two rather broad categories by hobbyists today. The first are the so-called small-polyped stony corals (SPS). These corals tend to have numerous small polyps covering the surface of a coral, and they usually contain branching or plate-forming species of corals. These include species in genera such as Acropora, Montipora, Stylophora, Seriatopora and Pocillopora.
Of these five genera, two species are almost bullet-proof. Stylophora pistillata is a relatively common branching SPS coral that can have brown, brilliant blue, pink or iridescent green polyps. The branches tend to be somewhat thick and stubby, which makes them extra sturdy.
The second coral is Pocillopora damicornis. It has finer, more numerous branches than Stylophora, and its polyps can be brown, green, blue, pink or even yellow in some cases. This species is the “white rat” of the coral research world and is found throughout the tropical Pacific. It is easily propagated via fragmentation, but it also produces its own planulae asexually and thus can easily populate a bare aquarium in a few years.
The second group of corals is loosely referred to as large-polyped stony (LPS) corals. These corals tend to have much larger polyps, or in some cases, the entire coral is a single polyp with a single mouth (e.g., Fungia spp.). These corals also have much thicker tissue, so the underlying skeleton is not readily visible, and the shape of the coral is much different when the polyps are fully expanded. Large-polyped stony corals are often mistaken for soft corals since the hard coral skeleton is not readily visible.
Several genera of LPS corals have spectacularly colored polyps. They have iridescent colors that fluoresce brilliantly in a multitude of patterns and color combinations. In the last five years, these corals have exploded in popularity and can command outrageous prices. Many of the LPS corals can also be fragmented and propagated; some can grow very quickly, while others will grow more slowly.
Four Coral Families
The first family of LPS corals I’ll look at are the Fungiidae. There are two genera that are among the easiest to keep: Fungia and Polyphyllia. These corals are free-living, meaning that they are not attached to a hard surface and live on the bottom on sand, gravel or among coral rocks. Mushroom corals (Fungia spp.) have very thin tissue, numerous short stubby tentacles over their surface and a large single mouth on the upper surface. Mushroom corals can be brown, green, purple, yellow or even orange.
Slipper or tongue coral (Polyphyllia talpina) has many more slightly longer tentacles that wave rhythmically in the current. These corals tend to be brown with lightly colored tentacle tips; some can exhibit a weak green fluorescence.
The family Pectiniidae contains two popular plate-forming circular-shaped coral genera, Oxypora and Mycedium, which are both commonly called plate, cup and chalice coral. These genera are similar in appearance, though Oxypora tends to have a slightly thicker, denser skeleton. Both genera are noteworthy, in that their polyps are relatively large and widely spaced, and they often exhibit vivid iridescent green, orange, blue or pink colors, contrasting with more muted coloration on the rest of the coral.
Another family for the reef aquarium is the Mussidae. These corals tend to have meaty tissue that is often brightly colored with strong contrasts in color and patterns. Acanthastrea have become the darlings of the aquarium hobby, especially with their increased availability from Australia. They have a low-growing encrusting growth form with the surface divided into dozens of brightly colored polyps.
Blastomussa is similar to Acanthastrea, but the skeletons look much different underneath the tissue. Blastomussa often have strikingly contrasted colors between the polyp mouth and the rest of the polyp tissue, though some species have a solid color. Other noteworthy genera are Acanthophyllia, Cynarina, Lobophyllia and Symphyllia.
The family Faviidae contains several “easy” genera, such as Caulastrea, Favia, Favites, Leptastrea, Platygyra and Diploastrea. These genera form mounds of colonies made of hundreds of polyps, though some forms can form plates in low-light conditions, as well. Again, the polyp mouth colors often contrast with the rest of the polyp but not as spectacularly as in the mussids.
Hopefully, you will now have a starting point that will increase your chances for success before you try your hand with more challenging soft corals and hard corals.