Genus Tubastraea - Amazing Dendrophyllids
Hardy and Beautiful if You Follow the Cardinal Rules
The Family Dendrophylliidae is made up of corals which mostly lack zooxanthellae, the symbiotic algae that lives in mutualistic symbiosis with many corals. What does this mean for the marine aquarist? Well it means that these animals do not have the same lighting needs as most corals with which the reef aquarist is accustomed. Good news? Maybe. But just because these corals don’t require the power of reef-ready lighting that many so-called SPS corals require, doesn’t mean that they are easier to keep. Here’s what you need to know if you want to keep them.
Many species of coral that don’t require light in order to support photosynthetic, symbiotic algae (zooxanthellae) within their tissue come from deep water where light does not penetrate. While providing reef-ready lighting is therefore not necessary, the challenge of successfully keeping these animals is far from over. Keep in mind that the deeper one goes in the ocean, the more stable the water parameters become. As such, Dendrophyllids, while not requiring intense, reef-ready lighting, do, more often than not, require absolute stability in all parameters—something that, as yet, has eluded many reef aquarists. This is rule number one: absolute stability in the aquarium’s water parameters.
Not all Dendrophyllids hail exclusively from the deep, but even those aposymbiotic genera commonly found in shallower water still have very specific husbandry needs. Take the genus Tubastraea for example. These corals, commonly called cup corals or sun corals, are beautiful animals that do not host zooxanthellae but which are frequently found at depths of less than five meters. Remarkably, these corals are relatively hardy animals if the aquarist understands their husbandry needs.
Species from the genus Tubastraea do not host symbiotic zooxanthellae, and so they must feed on what they can capture in the water column. The animal feeds by way of colorful polyps that emerge from tubular corallites. As such, the reef aquarist that target feeds his or her Tubastraea species will be rewarded with a hardy coral that spreads to adjacent substrate and throughout the aquarium. Rule number two: target feed these Dendrophyllids.
So, as long as you feed them, keeping cup corals or sun corals is easy, right? Not so fast. While target feeding this animal will yield positive results, one must keep in mind the downside to these frequent target feedings of large meaty morsels such as brine shrimp and mysid shrimp: excessive nutrients. It’s not a coincidence that these corals are found in high nutrient locations in the wild, but high nutrients in a closed system, like an aquarium, can spell trouble. This brings us to rule number three: when it comes to successfully keeping these corals, beefy filtration and frequent water changes are a must.
The fourth cardinal rule for successfully keeping most Tubastraea species is flow. At Blue Zoo, we often harp on the fact that, all things being equal, flow is more important than light when it comes to reefkeeping. This is especially true with these corals. Too many aquarists assume that, as a coral without symbiotic zooxanthellae, cup corals and sun corals need to be shaded from light. Placing one of these corals in a shaded spot, however, also often means placing it in a lower flow area of the aquarium, and this can lead to the animal’s demise. Rule number four: place them in high flow areas of the aquarium, even if this means exposure to bright light (but be sure to light acclimate them).
In short, Dendrophyllids from the genus Tubastraea can make excellent aquarium animals if the aquarist understands the cardinal rules to successfully keeping these animals. While not “starter” corals, the more experienced aquarist will find many of these corals both beautiful and hardy if he or she consistently meets their needs.