Stylocoeniella Coral Care
Stylocoeniella are an encrusting stony coral that has features similar to small polyp stony corals such as Montipora but also bear some similarities to the small polyp varieties of Goniopora depending on how extended the polyps are. It does have a common name, that being “thorn coral” because they often host these wormlike critters whose tubes extend out from the colony making it look like a thorny ball.
In terms of taxonomy, their classification is every bit as oddball as their name. They are a member of the sub-order Astrocoeniina and the family Astrocoeniidae.
These corals are found throughout Indonesia and Australia however it isn’t frequently imported. When they initially hit the market, Stylocoeniella were quite rare, but luckily they are a very easy coral to propagate and thus became more commercially available than one would expect given their spotty rate of import. Right now there are only a handful of color morphs, but who knows? As more color variants are discovered it may become as diverse any other coral.
That’s a little bit of background on Stylocoeniella. Let’s now talk about their care requirements starting with lighting and placement.
We primarily keep Stylocoeniella in low to medium light intensity here at Tidal Gardens. That translates to around 50 to 100 PAR. I haven’t really tried keeping them in brighter light, but it might be possible to get brighter coloration under the higher intensities. The main reason we don’t have them in higher light, believe it or not, comes down to space issues here. They did well in one of our lower light systems and grew like crazy so that’s where they stayed. When in doubt, try lower lighting intensities until it is clear that the coral is stable before ramping it up. The lowest lighting we have grown this coral in was around 40 PAR.
The coral seems adaptable and if we are able to clear some space out for them in brighter aquariums we might give them a try there. If you have a colony of Stylocoeniella and want to experiment with higher light, remember that lighting that is too bright risks burning the coral and it will happen quickly so if you start to see the coral starting to turn lighter and bleach out, move it to a dimmer location sooner rather than later.Low Light
Low light translates to about 30-50 PAR
Medium Light is between 50-150 PAR
High Light is anything over 150 PAR
Lighting is a loaded topic, so for a more in-depth discussion of lighting, please see our Deep Dive article.
As for placement, I would try to find it a spot lower in the tank, possibly even under an overhang. I probably wouldn’t place it on the top of the rock structure. Assuming it could handle the light at the top of your tank, I don’t know how well that would work aesthetically because this coral will stay kind of flat to the rock work and often times hobbyists are looking for a coral that is going to extend up towards the light structurally like branching corals. One other thing about placement to consider is future growth. Stylocoeniella is a fast growing coral that will spread quickly as it encrusts. You don’t want to crowd it right away and have it grow into neighboring colonies of corals.
Stylocoeniella appreciate low to medium flow. There are two things that I am looking to accomplish with flow for this coral. The first is to give it enough flow to keep it clean. Stylocoeniella is an encrusting coral that can quickly spread onto the rocks or bottom glass. As a result, it can attract its fair share of detritus. Detritus build-up can cause the coral to die back where it collects. Providing elevated flow around the coral can prevent this accumulation. Even moderate flow can serve to keep the coral clean, but pay attention to any detritus accumulation and consider altering the flow in your tank to compensate.
Detritus issues aside, one benefit to lower flow is that it gives the coral a chance to extend its polyps. In higher flow I notice that the polyps remain tight against the body and the whole colony resembles a Montipora or a Porites.
Providing periodic low flow is also beneficial for this coral for the purposes of feeding. Spot feeding Stylocoeniella is not something that a lot of hobbyists do, but I am all for it if people want to be proactive. They are not a particularly aggressive feeder especially given its small polyp size, and if the colony only receives strong flow it won’t get a good opportunity to capture food.
If you want to feed Stylocoeniella, what should you feed? Despite not being the most aggressive feeders in the world, there are a couple types of food that work well for target feeing. These three are amino acids, small zooplankton, and simply having fish present as a nitrogen source. In other words, treat it as you would any other small polyp stony coral. Most hobbyists do not go out of their way to spot feed, say, a Montipora so directly feeding a coral like Stylocoeniella may be a little overboard. Ours have grown exceptionally fast without a lot of attention. Still, if you feel like going that extra mile with feeding your corals, we can talk about it briefly.
Starting with amino acids, they are simple organic compounds that play a major role in building proteins as well as other biological functions at the cellular level. There are a little over 20 different types of amino acids. Most of them can be synthesized by the organism but some cannot be and must be taken in by feeding. Those amino acids are termed essential amino acids and they vary from species to species. Corals regularly take in available amino acids from the water column so it is easy to provide them with adequate quantities by broadcast feeding an amino acid solution. They are available from any number of commercially available reef supplement manufacturers. This may be the easiest way to feed Stylocoeniella because as long as amino acids are bioavailable in the water column, the corals will soak them up. If you want to know more about amino acids, I made a video going into great detail about them so check that out below:
Next up, Small zooplankton include organisms such as rotifers and cyclops plankton. There are two kinds, frozen and powdered. Both varieties do a great job of eliciting a feeding response from a wide range of corals. They are small enough that many small polyp stony corals can make a meal out of them but you have to be careful because they are a very nutrient dense messy food which can elevate your nutrient levels. Last point on nutrition, having fish in and around coral colonies tends to have a positive effect. Fish provide a steady dose of nitrogen and phosphorous which in small quantities is helpful for their nutritional needs.
Although coral nutrition is important, there is such a thing as too much of a good thing. Most of the nutrition Stylocoeniella needs will come from the lighting and they will be absorbing other nutrients from the water. If you are going to experiment with broadcast feeding or target feeding, start slowly with it and don’t expect explosive changes overnight. Having some phosphate and nitrate in the water is beneficial but overfeeding can cause these parameters to rise to dangerous levels that can be hard to remedy.
That brings us to Chemistry. There are three things to consider with this topic. First I’ll quickly cover the pollution parameters, phosphate and nitrate. Next, I will talk about the stony coral building parameters Calcium, Alkalinity, and Magnesium. Lastly, I will touch on some of the trace elements that might play a part in the health of Goniopora specifically.
Let’s talk a little bit more about Chemistry. Since we just talked about the potential problems associated with overfeeding, let’s talk about phosphate and nitrate. Phosphate and Nitrate are great general measurements of water cleanliness. They show up mainly in the food we provide the tank but decaying plant and animal matter in the aquarium can also elevate their levels in the water. We generally shoot for about 5-10 ppm nitrate and .05 to .1 ppm phosphate with varying degrees of success.
If Nitrate levels get too high corals may react negatively by taking on drab coloration or suddenly dying back in extreme cases. If Phosphate levels are too high, it may feed into an unwanted algae bloom or spur on the growth of other undesirable organisms that can stifle the growth of corals.
For a short period there was a push in the hobby to have near zero levels of nitrate and phosphate. This is done through techniques like carbon dosing or GFO which can aggressively bring those numbers down. Ultra low nutrient levels though come with their own sets of issues. There is such a thing as too clean and I would argue the problems caused by near zero nutrient levels are much worse than those caused by an abundance of nitrate and phosphate.
Corals require some level of nitrate and phosphate available to them. When starved out, the corals first take on a shrunken emaciated look and then they start dying off. After that there is a risk for blooms of unwanted organisms such as brown dinoflagellates that thrive in ultra low nutrient conditions.
For Stylocoeniella specifically, I would rather see Nitrate and Phosphate levels on the high side than barely detectable because we have kept them in systems with very high nutrient with little to no difficulties. In some tanks they are in 50 ppm of nitrate and 2.5 ppm of phosphate. Those figures are obviously super high but it is just to give you an idea of how tolerant Stylocoeniella are on the high nutrient side.
Moving on from the nutrient parameters, let’s consider building block parameters, Calcium, Alkalinity, and Magnesium.
Starting first with Calcium, it is one of the major ions in saltwater. In the ocean, its level hovers around 425 parts per million (ppm). As a coral grows calcium is absorbed from the water and used to forms its calcium carbonate skeleton.
Alkalinity is probably the most important parameter to pay attention to. It is not a particular ion, but rather a general figure of carbonate availability in the water. Technically it is the amount of acid required to lower the pH of saltwater to the point bicarbonate turns into carbonic acid. If you have more alkalinity, it can soak up more acid. Less alkalinity and you have less buffering capacity making the tank more susceptible to chemical changes.
In practice alkalinity tends to be the parameter that fluctuates the most, so if you can only manage one test, test for alkalinity. In natural sea water, the alkalinity of the water measures around 7 or 8 dkh though most salt mixes these days mix up closer to 8 to 9 dkh. Some aquarists like to overload this parameter a little and keep their tanks around 10 or 11 dkh with the belief that having elevated calcium and alkalinity in the water contributes to faster stony coral growth.
Raising both calcium and alkalinity together can be tricky because of how they interact. Calcium ions and carbonate want to react with one another. Addition of a calcium supplements often comes with a corresponding fall in alkalinity levels and vice versa. If you are experiencing this in your systems, it is normal, but wild swings are not. If you are experiencing dramatic swings of calcium and alkalinity every time you use an additive, you may want to look at your Magnesium levels.
So why Magnesium? Magnesium behaves chemically similar to calcium. It can bind up carbonate ions thus increasing the overall bioavailability of alkalinity compounds in the water. If you are tweaking calcium and alkalinity and getting strange results, you may want to make sure it is not your magnesium level that is low. In the ocean, Magnesium sits at about 1350 ppm.
Lastly, let’s talk about trace elements. What are trace elements? They are a catch-all descriptor of all the non-major elements in salt water. Trace elements all together make up less than 1% of the ions that make up salt water. The organisms in the ocean utilize these trace elements for various biological functions.
That should give you a little bit of background on the chemical parameters to keep an eye on.
Ok, that about does it for Stylocoeniella. So what kind of tank is Stylocoeniella best suited for? I see can see this coral being used in a couple of different ways creatively. I can see it used as a ground cover in high energy SPS dominated tanks as well as lower flow mixed reefs with other stony corals. It is a very fast growing coral and can quickly cover rock work basically acting as a much more exotic replacement for encrusting corals such as Montipora or Porites in high light situations or Pavona or Cyphastrea in lower light situations.
Either way, Stylocoeniella is an oddball coral that is a nice break from the norm. There are several monochromatic color variants but more and more multi-colored variants are popping up such as the red and yellow “burning banana variety” and we even came across one with a rainbow coloration that goes by “loony tunes” stylocoeniella online.
Check back periodically to see what varieties of Stylocoeniella we are growing here at Tidal Gardens. We are always on the lookout for new and interesting color morphs of this coral to add to our collection. Take care guys, and happy reefing!