Being able to identify Zoanthid Corals is both fun and impressive! With over 100 species and hundreds of color morphs to choose from, zoanthid identification can be difficult.
Zoanthids (Zoas) are characterized by a cylindrical structure called a polyp. At the base of the polyp is a mouth, surrounded by finger-like tentacles, resembling sea anemones which is why they are classified into the order “cnidarians”. Zoanthids however, are much smaller and coat themselves in mucus, unlike their anemone relatives.
But, what makes a Zoa a Zoa is no piece of cake… Zoanthids are known for their chaotic taxonomy and complicated morphological identification, as they look so similar to Palythoas (Palys), often confusing newbie hobbyists.
Zoanthid Identification & Taxonomy
Coral identification and taxonomy are tricky and a little all over the place. Most identification of Zoanthids was carried out 50 years before the invention of the light bulb in the early 1800s.
Now, you are probably thinking the same as me when I found that out – “but now we have lightbulbs and even newer technology like blue LEDs, so why is Zoanthid identification and taxonomy still a gray area?”
Well, it all comes down to lack of research.
Phylogenetic trees, that mark evolutionary descents, are developed over a long period and require scientific debates (which can take a while!) to solidify findings. As scientists have spent many years studying primates, the identification and taxonomy of humans can be agreed upon, however, marine biologists still are working with taxonomists to differentiate different coral genomes.
So, Is It Possible To Identify A Zoanthid At All?
Scientifically yes. Scientists identify the internal parts of corals to identify the species. This includes observing the septa (radiating vertical plates within the corallite wall), mesentery (abdominal membrane), and microscopic details including the size and shapes of nematocysts inside the coral. However, there are some differences that hobbyists may notice to identify them that don’t require a microscope and a scientific degree!
Key Features Of Zoanthids:
- Brightly colored, and not “earthy” looking – those are more likely to be Palythoas.
- Small polyps.
- Contrasting oral discs.
- Small tentacles.
- Marginal tentacles.
- Round sphincter (mouth) muscle in the middle of their base.
Even if you were a marine biologist, coral expert, and taxonomist with a home aquarium, you would be unable to publish research. I know, how crazy is that?! This is because phylogenetic research has to include a wild colony in their natural habitat, as coral polyps can adapt and change when they are exposed to different environments.
Genetic testing of coral is still in its early stages, small segments of DNA and RNA are being tested to complete the full genome of Zoanthids and other corals. If you still think Zoanthid taxonomy is not challenging yet, take a read of James Reimer’s paper on genetic testing here!
So, this is why we only identify corals to the genus level. Zoanthus is the genus that Zoanthids (and Palythoa) corals belong to. Scientists have now whittled down coral species by their different morphs to make it easier to tell them apart. Hopefully, these coral experts continue to expand genetic testing to make classification much easier for hobbyists!
Frederic Sinniger, James D. Reimer, and Jan Pawlowski may have discovered a new way to identify Zoanthids. Could this be the answer to our prayers? I hope so!
The use of DNA barcoding may be the future to coral ID, identifying new taxa, and creating more accurate methods of Zoanthid identification, all of which is super exciting!
Have Aquariums Affected Zoanthid Identification?
Your zoanthid does not just appear from thin air, they have to be collected from different parts of the world. Over the years they have started morphing in aquariums, which have made identification even more complicated.
As the morphing continues, each Zoanthid morph has a specific name. Some morphs have been named multiple times which makes the identification process much more difficult, which is why there are many debates online over Zoanthid ID.
Another issue is that one hobbyist may call the same Zoanthid a different name to yours, even though they are exactly the same. This also makes it difficult when people try to sell them on. The whole Zoanthid identification fiasco isn’t helped by the crazy and confusing names Zoanthids are given. However, there are a few names that almost every hobbyist will recognize, and those are the Zoanthid classics – for example, Rasta Zoas and Dragon Eyes Zoas.
Resources For Zoanthid Identification
So now we know that identification and taxonomy may be simple for a taxonomist or coral marine biologist, but when it comes down to the average hobbyist, identifying a Zoanthid can be difficult when we do not have the skills or equipment.
Without the extensive knowledge marine biologists and taxonomists have, when it comes to identifying your coral, there is no guarantee you will be 100% correct (even if you were to follow our simple Paly vs Zoa identification article).
Luckily, there are some amazing identification resources to help you out!
Zoabrary is great! You can select base color, lash (tentacle) color, ring color, and mouth color from a drop-down menu to help you identify your Zoanthid Coral, or if you already know the name of your coral, you can double-check it matches and learn more about your coral by searching it at the top.
Zoanthids.com has 17 pages of popular Zoanthids, including some of our favorites, Utter Chaos and Purple Monster Zoas! Like the “sort by” drop-down menu when looking at clothes online, at Zoanthids.com you can sort by featured, best-selling, alphabetically (A-Z and Z-A), price (low to high, and high to low), and date (old to new, and new to old). If you are after a new Zoa to add to your collection you can also select “filter by avail” to see what they have on offer!
For a quick photo comparison ID guide, ZOAHABIT.ID has tons of beautiful Zoa and Paly photos to identify your Zoanthid.
For easy access, why not use the new Reefs app which includes some awesome photos and information on a range of corals, including Zoanthids! The Reefs app by Manhattan Reefs LLC is not only great for coral ID, you can also identify fish, invertebrates, and those nasty unwanted pests.
Zoanthids are one of the most stunning corals that come in every color combination you can imagine. Identifying Zoanthids is still a “gray area” because of a lack of scientific research, however, there are ways you can identify these popular corals at a hobbyist level. This includes their famous bright colors, contrasting oral discs, and small tentacles.
As hobbyists, we are lucky because of the large community we belong to. There are many identification websites and even phone applications to help us understand more about one of the most popular corals in the reefing world.