When it comes to corals for home reef aquariums, there are few genera out there that come close to Zoanthus (plural: Zoanthids) in terms of collectibility. There are so many colors and varieties of this species (lovingly referred to as ‘Zoas’) available, it’s hard to not devolve into a frenzy of trying to have them all in your Zoanthid garden.
Best of all? Zoanthid corals can be grown by beginners, and the more basic morphs are quite affordable. Keep reading for everything you need to know about Zoanthid care and growing this fascinating coral in your own reef tank.
Zoanthid coral appearance
Their appearance is what has made these corals so immensely popular among aquarists. Zoanthids consist of a stem (stolon) with an often colorful polyp. They’re soft coral-like creatures that grow in a colonial manner, meaning they can form spectacularly dense mats. A large Zoanthid garden is quite a sight to see, with their almost fluorescent (often green) coloration and psychedelic circular patterns.
The genus Zoanthus contains a bunch of different species and even more color morphs. Just a few examples should be enough to explain why reef keepers love collecting Zoas:
- Purple and peach (Zoanthus ‘Pineapple Express’)
- Bright pink (Zoanthus ‘Pink Sakura’)
- Green, yellow and blue (Zoanthus ‘Rasta’)
- Dark red and dark purple (Zoanthus ‘Red People Eater’)
- Orange and blue (Zoanthus ‘Punk Rocket’)
Need we go on? Prices for these different Zoas obviously vary, but even for less than $30 you should be able to get a few nice polyps to start your collection.
Zoanthid natural habitat
Before we can talk about Zoas’ natural habitat, it’s important to understand what they actually are. The term ‘Zoanthid’ technically refers to a bunch of different coral genera in the scientific class of Hexacorallia, which also contains all the stony corals and sea anemones. Their specific order is called Zoantharia.
Now, when we talks about Zoanthids in the aquarium hobby, we’re usually referring to one type of Zoas in particular: the genus Zoanthus. This genus currently contains 14 different species, although not all of them are kept in home reefs.
The genus Zoanthus is considered cosmopolitan, which means it can be found pretty much across the globe. It pops up in both tropical and subtropical waters, particularly (but not always) on coral reefs.
Zoanthus species you may come across in your local aquarium store include:
- Zoanthus sociatus: from the Caribbean down to Brazil, in shallow to medium-depth coral reefs. Known as the green sea mat.
- Zoanthus sansibaricus: shallow waters in the Indo-Pacific. Varieties for sale include King Midas, Jungle Juice and more.
- Zoanthus solanderi: Caribbean coral reefs. Sometimes sold as Camouflage Zoas.
- Zoanthus gigantus: western Pacific, on shallow reefs. Varieties sold include the popular People Eater Zoas.
- Zoanthus kuroshio: found around Japan.
- Zoanthus pulchellus: Caribbean down to Brazil. Also known as the popular AOI Zoa.
- Zoanthus vietnamensis: from the western Pacific, like Vietnam and Australia. Known as pink button Zoanthids, varieties include the well-known and bright-green Radioactive Dragon Eye.
Did you know? Although Zoas are often referred to as corals to keep things simple, they’re technically more closely related to anemones.
What is a Zoanthid garden?
With the amount of different colorful species and strangely named varieties in the genus Zoanthus, it’s not surprising that these corals can become a bit addictive to collect. That’s how the concept of a Zoanthid garden came to be: the placing together of different Zoa varieties in order to create a sort of neon-colored underwater garden!
The care requirements discussed in this post apply to individual Zoa colonies, but of course, also to Zoanthid gardens. There’s really no difference between caring for a single Zoanthid or loads of them.
Zoanthid garden care
As mentioned in the introduction, Zoanthid garden care is pretty straightforward, and these corals can be grown by beginners. They do well in standard reef parameters and only require moderate flow.
As for lighting, their needs range from low to high, with the more brightly colored specimens liking things a bit lighter. Usually, 80-150 PAR should work well, meaning your Zoas can live in the bottom half of the tank.
When it comes to water parameters, one of the great things about these cnidarians is that they’re not overly fussy. Even if you’re a beginner and the water values in your aquarium aren’t always perfect yet, they should be fine. In general, as long as things are stable and you keep up regular aquarium maintenance, your Zoanthid garden will be happy!
Zoas are not known for being particularly aggressive towards other corals. In fact, they can often be the victim of other species’ defensive sweeper corals. Combined with the fact that their colonizing nature does mean they can overgrow their neighbors, it’s a good idea to give your Zoanthid garden at least a little bit of space.
|Name (Common, Scientific)||Zoanthus, Zoa, button coral, Zoo, colony polyp, button polyp, Zoanthus|
Zoanthid corals have two ways of feeding, just like many other coral species. They host Zooxanthellate algae, which provide them with nutrients through their own ability to photosynthesize. In addition to the nutrients provided by these symbionts, Zoanthids can actually feed by hunting. Their tentacles catch and kill small creatures with ease.
The problem is that the small creatures in question are not always present in sufficient numbers in our overly ‘clean’ home aquariums. As such, for the best growth, your Zoas will usually benefit from supplemental feedings of small frozen foods.
Feeding your Zoanthid garden isn’t difficult. Just get some mysis, copepods or other coral foods and turn off the aquarium flow. Apply the food in such a way that it will fall on the Zoas (like with a turkey baster), and they’ll take care of the rest themselves. You can turn the flow pumps back on after 15-30 minutes to blow the excess bits off the colony.
How to frag Zoanthids
Fragging (dividing) Zoanthid corals is technically a breeze, which is part of what has allowed them to become so popular in the aquarium hobby. Before attempting to frag yours, though, please refer to the paragraph below!
Once you’re all caught up on Zoanthids’ dark side, go ahead and whip out your protective equipment (goggles, sturdy gloves and preferably a face mask).
Make sure you have your plan ready to avoid mistakes! Lay out out the razors and coral cutters you’ll need, as well as rock, frag plugs and glue. For more details, check out this extensive reef2reef post.
Zoanthid garden troubleshooting
Although Zoas are considered beginner-proof, it’s always possible to run into issues. The polyps can refuse to open, the colony can catch Zoanthid pox (of course that’s a thing…) or the Zoas can even start falling apart.
Usually, these problems aren’t too difficult to fix. If you just got your Zoas, the most important thing is to give them some time. It can take a while before they settle in enough to start opening! If you’re still having trouble after that, start by checking the light levels. Your colony will appreciate a bright environment, but if things are too bright, the polyps can start dying off.
Thirdly, do a full water test, as low water quality can cause stress and less than stellar looks in your Zoanthid garden. And lastly… cast a suspicious eye on the colony’s tankmates. Might anyone be nipping at them when you turn your back on your tank?
Before you even consider adding Zoanthid corals (or their cousins, Palythoas) to your aquarium, think for a second about the fact that they contain a potentially DEADLY neurotoxin: Palytoxin.
No, not all Zoa’s can kill you, nor will they attack you while you sleep. However, it’s incredibly important to know that this toxin is released as an aerosol. That means you should be wearing protective equipment while handling Zoas.
You should never let Zoas be exposed to heat (like from trying to kill them with boiling water or letting them come close to hot aquarium lights). Handling colonies should be done underwater only and if you’d like to try your hand at fragging, you should do so with the utmost caution as well as a solid plan of action.
Need help with your Zoanthid garden?
An aquarium with a colorful, healthy Zoanthid garden is an absolute joy to see. Setting up and maintaining a reef is no small task, though. Especially if your corals contain neurotoxin!
Short on time or feel like you lack the specialist knowledge? Contact FantaSEA Aquariums with your fish tank ideas or struggles so we can help you out.
Sources & further reading
Karlson, R. H. (1988). Growth and survivorship of clonal fragments in Zoanthus solanderi Lesueur. Journal of experimental marine biology and ecology, 123(1), 31-39.
Reimer, J. D., Ono, S., Fujiwara, Y., Takishita, K., & Tsukahara, J. (2004). Reconsidering Zoanthus spp. diversity: molecular evidence of conspecifity within four previously presumed species. Zoological science, 21(5), 517-525.