coral of the week { Zoanthus sp. }


Premium Member
week #15 coral of the week { Zoanthus sp }. This coral is pictured on page 302 and 303 of the book the Reef aquarium volumn #2 by Julian Sprung.

Every week I will post a new coral and I want you to post everything you know about this particular coral. Everything from common names, how hardy they are, water temp, water flow, lighting, water parameters, fraging, spawning, related corals, scientific names, feeding, best ways to ship, etc. Post your pictures for identification. Please tell us about your system so others can duplicate your success. Also email me for request on which corals you would like to see in this section.

Well I guess I will start thing out this week.
Here is a picture of mine:

There are about 5 different colored polyps on this rock. if you look close you can see orange, green with orange center, brown and there are pure green ones. My calcium is at 430 and alk is between 8 and 10. They are under 250 watt iwasaki and 2 vho actinics. The lighting is hung about 6" above the water and the rock is about a foot below the surface. The ones that are directly under the halide are more red but the polyps are smaller also.

We have 3 or 4 different types of zoanthids in our tank. We have a generic brown kind (which has pics on our website). Then we have some light green, some light blue, and a darker blue (no pics of these yet). The brown ones started as one polyp that came in on our LR. Now it is probably between 100 and 150 polyps. I've seen them called either zoanthids or button polyps.

Our tank is a 46g reef with 2X96W PC and 1 30W NO bulb. The temperature is 80-82 F. These polyps don't seem to care about the conditions. The original one lived through the entire cycle. Some of them are in the shade, some are near the lights. Some are in high flow, some are in low flow. As long as they are solidly attached to something, they seem to do fine. We top off with kalk, and we use B-Ionic every morning. The tank is fed fairly heavily.

We noticed that some of the polyps didn't do very well when they were too close to some Ricordea mushrooms, but others have been unaffected by contact with an anchor coral (Euphyllia ancora).

As for fragging, you can just cut a few polyps away from the colony and attach them somewhere else. Or, even better, you can place a small rock near a growing set of polyps, and then remove the rock after they've grown over it.

That's all I can think of off the top of my head.




I have several varieties of zoanthids in a 55 gal. bowfront corner tank.They are an excellent beginner "coral". The tank is 5 months old. Parameters are

Ca 435 ppm
Alk 12.5
Temp 76

Lighting is

175watt MH 10K temp
144watts PC mixed 50/50 daylight and actinic

Water Movement

Fluval power filter - no media
2 powerheads
wavemaker power strip


CPR Backpack

Zoanthids seem to grow readily in these conditions. They form a mat, covering most anything they can attach to. I have seen them eat misid shrimp and brine. They love light, and do much better if they get at least an 8 hour photoperiod. Mine did better after I added MH lighting.
Grainy pic, but here are mine. I've noticed that they are doing much better since I moved them from under the MH bulbs.

Heres a few of mine. The two top ones were hitch hikers on some Fiji live rock, the bottoms one I bough about four years ago form an LFS. They grow pretty fast once they are established, but still slow compared to most other soft corals. I dont directly feed them and they are all under MH and VHO lighting in medium currents.

Had these for going on three years, have tripled in number and have and arrow crab (decorator variety) that loves to use the littler ones for camouflage.

55 gal, 400w MH, 80w actinics, mod current, on the edge of the light spread, all are a brown with bright green tint that shows up very well with actinics alone on...almost alien. Add no supplements and use tap water, IO salt, no skimmer.


[Edited by nuff2000 on 03-08-2001 at 11:28 PM]
OK, is there a difference in species between the ones that are 1/2-1" tall and the ones that are only 1/8" tall? Is it a lighting issue? Do they extend like shrooms do? It also seems like the shorter ones are more expensive, how true is that?
Thank you,

I've always thought macro pics of these were awesome:)
Here are mine

These were hitch hikers from fiji rock


And these I bought, they are now more yellow

a truely amazine collection of pictures and information,
as someone who lurks in the shadow of the captive reefs,
this is really helping me to design my own tank, many, many


I noticed in your photo a single large polyp that is colorless. It is located slightly above and to the right of the arched cave, at the bottom of the rock. I recently bought a similiar rock, but I have noticed more of these "bleached" polyps. Does anyone know if this is related to light and placement or if it is disease related? Some others scattered about on the rock are starting to get a speckled, stark white center. On another adjacent rock I am seeing a distinct row of polyps that are simiiliarly bleaching or remaining tightly closed. Both rocks were purchased from the same tank a week ago. I estimate my tank has about twice the VHO light that the LFS had them in, but it is not excessive,440w on 60g. Most of the other polyps on these rocks look much better now than they did at the dealer's. The sick ones concern me and I don't know what to look for. Any advice is appreciated.
Thanks, Marty
Tank parameters are all normal and stable. Other animals and zooanthids look good.
My turn I guess!




My perspectives and/or experiences on zonathid care.

Lighting - Grow faster and look better in high light, but also do well in moderate and low light. Growth rate in low light is greatly reduced. MH, PC, VHO, NO all are fine as long as there is enough light.

Current - Moderate to high current is best as it helps keep hair algae from getting a foot hold. (As with green star polyps, it is difficult to eliminate all hair algae if it takes hold growing between the polyp stalks.) Direct current from power head discharge is a bit too much.

Feeding - Most of mine do not take food of visible size. The palythoa, some of which are posted above, usually do take large food directly. An overdose of filter feeding food such as Selcon can kill the polyps. Don't worry, an overdose generally means directing a substantial amount right on the polyps. If this happens they will close and likely rot away instead of re-opening.

Bleaching- Extremely resistent to bleaching, but it can happen. I have seen zoanthids bleached by a rapid and large change in alkalinity, very bright light especially if its a big change, and lack of light. Those losing their color due to lack of light can usually be brought back. If buried without light too long, they will eventually die.

Alkalinity - Tolerant of a high range of alkalinity but htere's no reason to get carried away and very abrupt changes can be detrimental, but this is usually the case for anything.

Reproduction and growth rate - Grow much faster in higher nutrient systems and are very easy to propagate. Pulling from the substrate with pliers, cutting near the bottom of the stalk, breaking the rock they are on and pulling apart, or jsut waiting for them to spread to another rock are methods of propagation.

Pests - Pests and/or predator are not usually a problem but inspect newly imported colonies for small black and white snails that have a cone shaped covering over their foot. These snails do eat the polyps and are common on newly imported colonies.
Marty M
That is actually a Protopalythoa which is considered a zoanthid but not a Zoanthus which is a species of zoanthid. They are ussually cream colored to brown, or sometimes have green in like the first picture in Hartman's post. Hartmans first picture is also Protopalythoa sp. by the way those are great colors. Also hartmans second picture is Parazoanthus. I am happy he posted them so people can see the difference. Also Does anyone have a picture of a Heliacus snail that prey on Zoanthids. Niven the ones that are 1-1/2" tall are probably Protopalythoas.

...some guessing on my part... :p All of these are probably from the family Zoanthidae

note the ones with pointed tentacles and thin oral disk edge..such as the top 2 pics by Hartmans. I think they might be some kind of Protopalythoa genus. KE also shows some of them, the green ones. Protopalythoa also can show sand encrusting the stalk, though it isnt always visible in captively grown ones.

The Yellow polyps in Hartmans are perhaps Parazoanthus. These too are Zoanthids, though again a different genus.

The rest are 'typical' zoos, like the ones I have. :p

random babling,


Oops! did I just repreat what shred said?! :)
Here is a picture of a heliacus snail that prey on zoanthids emailed to me by Mutagen .