FAQs about Zoanthids 1 Related Articles: Zoanthids, Sea Mat: An Ocean Of Color For The Aquarium by Blane Perun, Related FAQs: Zoanthids 2,  Zoanthids 3,  Zoanthid ID, Zoanthid Behavior, Zoanthid Compatibility, Zoanthid Selection, Zoanthid System, Zoanthid Lighting, Zoanthid Feeding, Zoanthid Health, Zoanthid Reproduction,

Vanishing Polyps Hey guys <Scott F. is the guy tonight> Thanks for all your help over the years. I have another question. My yellow polyps seem to be disappearing. The ones that are there look ok, but their numbers are decreasing.  I also have several other corals including xenia (my h20 quality indicator) all growing quite well.  All tests are where they should be: ph 8.3, sal 1.0025, ca 420, alk 10dkh etc...  I have 2 theories.  1st- they are low in the tank. Maybe not enough light?  I have 5w/gal VHO in a shallow 50g breeder w/DSB, so they're about 10" deep, but slightly shaded from another rock outcrop. <These colonial anemones are usually quite durable, and adapt to a variety of lighting schemes and environmental parameters. Your lighting seems fine> 2nd- The other night, I saw a couple of these bugs about 8-10mm looked like a cross between a camel cricket and a roly-poly. Brown in color. Occasionally I'll see an exoskeleton floating around the tank.  Anyway, they looked like they were eating at the base of the polyps. Maybe they were eating something around it, I'm not sure, but something's causing these things to disappear one by one while the ones remaining look ok. Ideas? If its the bugs, what can I do to keep the population in check? Thanks for the help. Neil <Well, Neil, I doubt it was the "bugs". These are actually amphipods, most likely, and are highly desirable creatures to have in your system for a variety of reasons, not the least of which is that many species of fish (wrasses, dragonets, etc) love to eat 'em! Aquarists often go to great lengths to "cultivate" "pods" in their systems, so consider yourself "blessed"! It's hard to say from here what is causing the polyp population to dwindle. Your environmental parameters and lighting sound acceptable. I am assuming that no other corals are in contact with the polyps? Do you have any fish in this system, or perhaps crabs or shrimp of some type? I had an arrow crab once that absolutely snacked on my yellow polyp population-ate 'em one by one! Now, that is probably not a typical occurrence, but it goes to show that you need to look at things beyond the obvious. Do review your livestock and see if there are any "suspects" among them, such as angelfish, butterflies, or other fishes that are known to eat coral polyps. In the absence of poor environmental conditions or obvious disease, I'd operate on the assumption that there may be a predator in the mix somewhere-but not the "pods"! Good luck! Scott F.>  

Red Stick Polyps... Hi... <howdy!> I've pored over the WetWebMedia site and haven't found the answer to this question, so I was hoping you could help. The LFS has a livestock I haven't seen before (a rather rare occurrence for me). It's a long, hollow tube about 0.5 inches in diameter, maybe 6 inches long. The tube has many of what look like pink polyps (or red), although they are rather tall (maybe 0.5-0.75 inches long each); they are all along the tube, all around it (maybe 50 crammed into this small area).  <yep... an aposymbiotic zoanthid symbiotic with the tube/sponge upon which it rests> The store says they are actually a form of anemone, and I suppose they could be,  <eh... sort of. The are commonly called "colonial anemones"> but they apparently don't propagate off of the base tube.  <separate creatures but dependant upon each other> For placement, they mount it on a chopstick, which they stick into the rocks and have it hang into the middle of the tank.  <it makes little difference how they mount them... they will starve to death within months like most. The advent of refugium strategies and the culture of natural nanoplankton someday will help us to keep this filter-feeder. Till then... save a life and don't buy it (spare the re-ordering of another by your sale, that is)> It's rather pretty, and the LFS calls it "reef safe".  <and "reef starving" too in aquaria> I'm curious what it actually is, and if you have any experience with it. Thanks a ton...:) Arthur <a beautiful creature that needs a species specific tank and possibly live plankton drips (daily) to survive. Not for any mixed reef aquarium likely. Very difficult to keep. Best regards, Anthony>

Mushrooms and Zoanthids not faring well Hi, <cheers> I have a 100 gal diamond tank with 4-95watt VHO and 1-55watt PC lights. I have a wet/dry and skimmer.  <keep an eye on those nitrates with that wet/dry ;) > There are assorted fish plus a ritteri, bubble <Hmm... how long have you had the Ritteri and the bubble is what? anemone or coral> and golden toadstool. All my water tests are good.  <good...?> I add iodine and Kent CB parts A and B to maintain alk and ph. Here's the problem. I have never been able to keep mushrooms and polyps alive!  <a common problem is mixed garden aquaria so severely assorted as your (anemone, LPS, octocoral, etc)> The mushrooms start off great, grow for a month or so and then slowly die off. The polyps just stop opening and over several months die off. HELP! I don't understand. Dave <no worries here... it is quite natural and a sign that your tank is not as nutrient rich as most. Corallimorphs and Zoantharians usually hail from deeper, nutrient rich waters... where as your Ritteri and Toadstool hail from very shallow, lower nutrient waters. In the wild they are separated by perhaps more than 60' of water! It would be impossible to homogenize the parameters of a tank to suit the needs of both in the long run. Best regards, Anthony>

Zoanthids Good Morning Bob, Anthony and the rest of the WWM crew. <Steven pro this morning.> Let me start by saying Bob I bought your book "The Conscientious Marine Aquarist" and keep it close by. <As do I.> Now my reason for writing today is this, I have a colony of button polyps, brown and then green, under actinics. These little guys were gorgeous while in my 55. A few months ago I wrote you about transferring to my new 125 *reef one day* Still building :) anyway I did all the things you said I should and still almost 5 months into it they haven't opened all the way in sometime, now here's my dilemma. *I have many* My tank specs are as follows. 125 6ft standard tank 220 watts of compacts on each side (running day and actinic) and in the morning and evening blue moons are on. a huge sump with an AMiracle skimmer putting out a good amount of yucky stuff. I keep a log and biweekly I add essential elements and weekly sometimes every few days I add calcium, stron-mag, iodine. my tests read as follows. Amonia-0 nitrate always reads 5 or less very small trace of it nitrite-0 ph-8.2 CA- 450. <The above sounds ok> Now My LFS sucks so I have to drive an hour away to one I trust (Rehobeth beach) I went there this week to talk to them and get something new for my tank (coral) but they said maybe I should check for phosphates, so I spent the money for the test kit and for the remover in case, and guess what *0-PHOSOHATES* needless to say I was happy about it but mad as I wanted this little piece of rock with 6 different corals on it :( so after this long book to you I'm praying that maybe the best *you guys at WWM* can shed some light on the problem. I have moved this colony around all over every few weeks to darker spots then brighter spots, <There is your problem. It takes "corals" time to acclimate to different lighting conditions and every time it is just about ready, you become discouraged and more it in an attempt to encourage the polyps to open. Please, select a good place and leave it there.> I run wavemakers in the tank but they are not in the fast current of it, I feed phytoplankton 2 times a week, <These polyps do not eat phytoplankton.> now last but not least they are on a huge piece of rock (I'd say about 20 inches long and about 8 inches wide) all my mushrooms are happy, even a baby rose anemone came as a ride along on live rock has grown so much in just a few months, also coralline algae growing on glass and such I have about 75 red and blue leg crabs and the red legs crawl on that piece of rock a lot, in fact so do the others and the snails. Please help as I'm really wanting to add new corals but I am leery due to the Zoanthids. I have about 150 lb. of live rock in there, will be adding another case soon. <150 pounds in a 125 sounds about right to me.> As always thanks in advance, it's always a pleasure speaking to you all. Sincerely, Robin <Have a lovely weekend! -Steven Pro>

Re: Zoanthids Good Morning Steven, <Morning> Wow so all this time I'm just adding stress to them :( <Yes> I feed phytoplankton due to all the other filter feeders in the tank. <It can be beneficial to feather dusters, clams, and some leather corals to name a few.> So how long does it take usually for them to adjust as you say. <Depends on how well you matched their conditions (lighting, water movement, etc.). I would wait one month without any moving around.> I want to add more corals just a bit leery about it. Thanks as always your the best! Take care and have a great weekend! Robin <You do the same. -Steven Pro>

How to feed zoanthids? Bob, Antoine, Steve and J (which means??) Greetings! I bought a little colony of zoanthids, they look like the ones you have in zoanthids section. http://www.wetwebmedia.com/Cnidarians/Anthozoans/ZoanthidPIX/ZoanthidAQ5.jpg (this photo belongs to you) So, my question is: How can I properly feed this little fellows! I read through your FAQs about feeding but I can't understand how those little things can eat a bit of shrimp! <It is all a matter of relative size. Nothing bigger than a mysis shrimp, for smaller ones the Sweetwater Zooplankton (daphnia) are an appropriate size.> They really need additional food giving by my hand or they can manage the food issue by themselves. <Better to target feed vs. dumping large amounts in and hoping they get some, in particular if you want to maximize growth.> Thanks a lot. Carlos <You are welcome. -Steven Pro>

Zoanthids BUTTON Polyps HELLO, I HAVE A TANK WITH BUTTON POLYPS AND I SEE LITTLE CREATURES THAT LOOK LIKE BUGS LIKE LITTLE COCKROACHES THAT COME OUT OF THE ROCK WHEN THE LIGHTS ARE TURNED OFF, <they are amphipods and highly beneficial detritivores for your tank. Very good zooplankton to feed fishes and corals> ALSO THEY ARE DOING SOMETHING TO MY POLYPS BECAUSE THEY WILL NOT COME OUT. <not correct my friend... they can not harm your coral. The worst they could do is scavenge decaying tissue. They are harmless and VERY desirable to have. Your coral is irritated for another reason> WHAT ARE THEY AND WHAT CAN I DO ABOUT IT BEFORE THEY DESTROY ALL MY POLYPS? THANKS TED QUERCIOLI<changes in light or water quality are the two most likely cause to the polyps not opening. If the coral is new or has been moved recently, then the polyps may be trying to adapt to the change in light at the new depth or position.>

Zoanthids? Hi guys, I have a quick identification question. We went and bought some polyps this weekend that look like giant button polyp zoanthids that are a brown and white marble sort of color. They are very large and we were told at the LFS that we bought them at that they are called cinnamon polyps.  <I know them very well. I poisoned myself three times in ten years as a coral farmer with them. They are potentially fatally toxic, but know that many corals are that you don't know about. Besides not eating your corals <smile>, you often hear that one should wear gloves in the aquarium to protect your corals from contamination on your hands and to protect your of course from these stinging animals. This is a good reason. Just do not handle them with cuts on your hands or propagate them without wearing gloves <G>. The worst that you are likely to encounter is a metallic taste in the mouth if you work in the tank without gloves. The creature is also known as the Giant Sun Polyp, Protopalythoa grandis. A beautiful creature that also occurs marbled with pink and green! as well as with radiating red and white stripes.> We have not been able to find anything on Wet Web that looks like them or on the rest of the internet, probably because we have the wrong name for them. If you could please maybe give me an idea of what these giant polyps are.  <yep...Giant Sun Polyps <G>. Always use the name (Proto)palythoa grandis or P. toxica (Pacific)> Thanks for any info. you can give. Marci = ) <best regards... and hear is a fascinating article on the toxin in such Zoantharians:

The Fantastic Story of the Modern Discovery of Palytoxin This article was written by Professor Bob Williams of Colorado State University, for his publication: The Nerd Street Journal. Palytoxin was discovered by Professor Paul J. Scheuer at the University of Hawaii. The story of how this toxin, and its producing organism was found is quite interesting. Prof. Scheuer has made a hobby of reading ancient Hawaiian folklore through various library collections on the islands. He came across a reference to Limu make o Hana (deadly seaweed of Hana) in his readings. This is the Hawaiian phrase for a toxic organism which Malo (Hawaiian Antiquities, 1951) described as follows: "In Muolea, in the district of Hana (Maui), grew a poisonous moss in a certain pool or pond close to the ocean. It was used to smear on the spear points to make them fatal.....The moss is said to be of a reddish color and it is still to be found. It grows nowhere else than at that one spot." According to Hawaiian legend (manuscript notes by Katherine Livermore on file at B. P. Bishop Museum, Honolulu), there lived in the Hana district a man who always seemed to be busy planting and harvesting. Whenever the people in the neighborhood went fishing, upon their return, one of the group was missing. This went on for some time without the people having any explanation about the disappearances. At last the fishermen became suspicious of the man who tended his taro patch. They grabbed him, tore off his clothes and discovered on his back the mouth of a shark. They killed and burned him and threw the ashes into the sea. At the spot where this happened, so goes the legend, the limu (moss) became toxic. The tidepool containing the poisonous limu subsequently became kapu (taboo) to the Hawaiians. They would cover the limu with stones and were very secretive about its location. They firmly believed that disaster would strike if anyone were to attempt to gather the toxic limu (later named Palythoa). Prof. Scheuer collaborated with Professors A.H. Banner and P. Helfrich of the Hawaii Institute of Marine Biology, and through a very elaborate chain of local Hawaiian informers and several cases of beer to loosen (frightened) lips, the location of the fabled tidepool was reluctantly disclosed. The tidepool was located at the end of a lava flow at Muolea (Kanewai), south of Hana, Maui. Divers collected a small sample of the toxic limu on December 31st, 1961. During the collection, local residents reminded the collection team of the kapu and the high probability of impending misfortune. Coincidentally, that same afternoon, a fire of unknown origin destroyed the main building of the Hawaii Marine Laboratory at Coconut Island, Oahu (the Institution of Drs Banner and Helfrich). Scuba divers have subsequently combed the surrounding ocean front near the tidal pool and did not find the Palythoa growing anywhere else except in the original location pointed out by local residents. The tide pool turned out to be just six feet long, two feet wide, and 20 inches deep at low tide. The crude ethanol extracts of the Palythoa toxica proved to be so toxic that an accurate LD50 was difficult to determine. More recently, the toxicity has been determined to be 50-100ng/kg i.p. in mice. The compound is an intense vasoconstrictor; in dogs, it causes death within 5 min at .06ug/kg. By extrapolation, a toxic dose in a human (obviously not determined) would be about 4 micrograms!!!. It is the most toxic organic substance known. Following the isolation of the crude toxin by Scheuer (reported in Science (1971) 172, p.495), it was nearly 11 years before the correct structure was unraveled. two research groups, one at the University of Hawaii (led by Prof. Richard Moore, a student of Scheuer's) and one at Nagoya University (led by Prof. Hirata) put together the correct chemical structure in late 1981. Following that, Prof. Yoshito Kishi at Harvard University decided to try the complete chemical synthesis of the Palytoxin molecule. This monumental task was completed in 1989. The Palytoxin molecule has the longest contiguous chain of carbon atoms known to exist in a natural product(115).The molecule has the formula C129H223N3O54 and contains 64 stereogenic centers. Adding this with the double bonds that can exhibit cis/trans isomerism means that Palytoxin can have more than one sextillion(1021) stereoisomers! This staggering molecular complexity should indicate the difficult nature of designing a stereocontrolled synthetic strategy that will produce just the one correct (natural) stereocenter out of >1021 possible stereoisomers (Kishi did). The Palythoa toxica species has more recently been found near Tahiti, but produces a slightly different compound. The Tahitian organism is not widely dispersed in the coral reefs off Tahiti, but does not appear to be as localized as it is on Maui (a single tidal pool). 

Question?, Coral ID Can you please identify this piece for me? I add calcium, iodine, strontium and molybdenum, and Phytoplex to the system through out the week. Does this piece require any thing else?  <possibly doesn't eat much or any phytoplankton. Zooplankton is much better for most coral. Phyto for clams, gorgonians and some Neptheids in gross terms> Does it need low, medium or high lighting. <it is a Zoantharian (zoanthid). Likely moderate to high light and feeding by absorption supplementally but little organismal feeding (Protopalythoa relatives are heavier feeders organismally).> Thanks <best regards, Anthony Calfo>

Brown Button Polyps (Zoanthus sociatus) closed! Hello everyone!  <Cheers, my dear... Anthony Calfo first one back from Germany/Interzoo. My batteries are recharged, the buzz from gallons of seriously tasty beer has worn off and I am ready willing and able to relieve/assist my fellow crew members left holding up the fort!> I feel I am beginning to get back on track here on the Cape. I've been reading and testing and adding to my systems water. The numbers are beginning to look better. I do have another problem cropping up though. My Brown Button Polyps (Zoanthus sociatus hasn't been looking too good for about 2 weeks now. Lots of the trumpets are staying closed a lot of the time. I have 2 questions about this: (1) Can coralline algae encroach on them and kill them? My rock is covered with Maroon Coralline (Peyssonnelia sp.) and it is on the rock with my polyps. <not at all likely/possible. This/most cnidarians are far more aggressive> (2) I have recently been feeding the polyps black worms. I suck up the worms with a turkey baster and stuff their mouths. Is this a bad thing? <not at all a bad idea... the direct feeding route is generally the best for inverts that feed organismally/particles. However, your choice of food is a problem. Even rinsed of freshwater... there is still inevitably freshwater contained within the prey that is unnatural if nothing else. If you suck them up in a baster from a freshwater slurry it is that much worse. And more importantly it is an inferior food source alone since it is not of marine origin. Let me suggest that you feed small whole prey or finely shredded meats of marine origin like mysids, Gammarus, krill, zooplankton etc. And thaw in a solution of saltwater for baster feeding> Maybe they are digesting, hence the long period of closed polyps? <nope> Thanks guys for your work and knowledge. I'd be lost with out you!!! <that still doesn't explain how/why we are still lost ourselves...ha!> Pamela <kind regards, Anthony>

Propagating Zoanthids Hi Bob and all you other guys! Can one of you please tell me how to propagate Zoanthus sociatus ? Or any of the Zoanthus species for that matter.  <should be done with great caution! I highly recommend that this be done in a dedicated prop tank and only after much experience with other corals in propagation. The activity is actually quite easy by separating individual polyps with a scalpel or sharp chisel. The problem is that zoanthids contain Palytoxin and it is frighteningly dangerous to humans in some species. Eric Borneman and I have each written on the subject in our respective books. I have been poisoned three times in ten years of coral farming with this species. Please research more on the safety and care of these corals in propagation first> I have a rather large colony and I would love to see them around the tank rather than just one huge clump! Thanks! Pam <kind regards, Anthony Calfo>

Looking for Colonial Anemone Info. Mr Fenner: I read an article on zoanthids on your site. I was wondering if you may know of any good articles or books where I can find some additional information. My interest is in identification, and documentation of captive rearing. <The piece itself: http://www.wetwebmedia.com/zoanthid.htm has a bibliography at the end. I would look for these and other hobbyist articles, and book references further "up on the scale" of cnidarians, invertebrates posted on WetWebMedia.com and at the book reviews posted there on marine topics, and though you are fully familiar, in a computer search of pertinent literature, as detailed here: http://www.wetwebmedia.com/litsrchart.htm Bob Fenner> Thanks Blane

Yellow polyp feeding Hey Bob, So, I just started adding my first coral per say to my tank, and I've started with a colony of yellow polyps and some button polyps well I think that's what the second ones are) Anyway, I read about feeding the yellow polyps and I want to confirm a few things... Stats: I have a small colony of about 20 yellow polyps in a 25 gal min reef with a 32W power compact retrofit on an eclipse hood. All my nitrites and nitrates are 0 on account of about 10lbs of live sand mixed with about 10lbs of fine crushed coral all together with 25-30lbs of live rock. Tanks about 1 1/2 years old and has a Skunk back Pseudochromis and bicolor blenny. and a 9hr light cycle on my light timer So.... my questions are, is the lighting fine for the polyps, i.e. is 9hrs enough? <Yes> In feeding the polyps, I have some frozen mysis and brine shrimps, which I feed to the fish, and I noticed that the polyps close up and then re-open, and one actually caught a whole shrimp during the feeding. Is this an example of them catching food, or being upset by the frozen food?  <The former> (I'm assuming they are catching what they want, but I wanted to make sure) Last, how often should I feed them? Do you think they are getting enough when I feed the fish? <Likely so... with careful observation you will be able to tell if they're "getting enough"> or should I mash up some of the shrimp as squirt it at them like I've read some places? (Including your site) <Not necessarily... practice for now> Oh, and one more last question, What do you think would be better for my tank, a Rusty Pigmy Angel, or a Flame Angel if I want to get clams eventually? <About the same. Bob Fenner> Thanks!!!! David

Re: Yellow polyp feeding thanks for the help! they look like the grew already!!! How often do these little guys multiply? <How much? Indefinitely... given food, space, a lack of predators, competitors... slowly though... doubling only every several months in colony size. Bob Fenner> Thanks a bunch David

Zoanthids Hi Bob, I've checked on line and in books for information regarding zoanthids, but most of what I've found has been a repetition of the fact that they are hardy and easy to grow with little actual information on their care. I was hoping you could help me out here. <Hope to> I've been keeping a saltwater tank for about 6 months and am branching into the world of the reef tank. To start, I've added a zoanthid colony. For the first two weeks, the zoanthid seemed to be doing fine. Now, it's started to shrink. It is not opening up as much as he used to, but it is having new growths. Why is it shrinking? Is there anything I can do to prevent this? My tank setup. 40gal tall 78 degrees f SG = 1.025 Ph = 8.2 - 8.4 Ammonia = 0 Nitrite = >0.3 <this should be zero> Calcium = 450ppm kH = 11 2 -- 55 watt Power compacts 10,000k 1 -- 15 watt Actinic 03 fluorescent The zoanthids are about 8 inches below the water surface (and therefore the lights) and are slightly below the power head so they are not directly in it's current. Thanks, Chad Bowser <Mmm, not much more to say that isn't posted on WWM: http://www.wetwebmedia.com/zoanthid.htm Your new colony may have just shrunk due to the moving... water seems okay, same with set-up. I would just give this grouping more time. Bob Fenner> 

PRUNING PALYTHOA AND ZOANTHUS COLONIES I have been having great success in growing Palythoa and Zoanthus polyps, to the point that they are over running the area that I would like to maintain them in. What is the best way to prune back these polyps? <Actually, to separate/isolate them on their own rocks... leaving a gap so they can't spread further... Bob Fenner> Look forward to your response. Regards, Jim

Zoanthids Hi Bob, I have a 55 gallon tank that I want to make into a pseudo-reef (pseudo because I have only 1 96-watt PC for lighting).  <There are reefs in the world with far less illumination> I have about 70 lbs. of live rock, a Purple tang, diamond goby, pacific cleaner shrimp, a large featherduster and a colony of orange zoanthids. All inhabitants are doing well. I plan on getting some mushrooms in the near future. My question is, what other types of sessile inverts can I add with this amount of light?  <Many, many... there are hundreds of ahermatypic true/scleractinian corals alone... and gorgonians/sea fans... Much more than would fit a hundred 55's.> I get conflicting reports from LFS people; some recommend star polyps, other sources say they need lots of light. LFS says zoanthids need lots of light, but mine are doing fine.  <Both groups have members that will do fine in your system> I'm afraid to buy more before I get more info, but it's hard to find specifics on the beauties I see in the store. What do you recommend? <Investing your time, money in some of the fine standard written works available: Eric Borneman, Sven Fossa, Alf Nilsen, Julian Sprung, Charles Delbeek, Ron Shimek... should all be known to you. Bob Fenner> Thanks a lot, Suzanne.

Mysterious life forms Hello, I was hoping you could help identify a couple of mysteries in my 72 gal reef tank. <I'll try> The first came with a piece of green Alcyonium leather coral that got through FFExpress. On the small piece of rock that the coral is attached to there are two identical creatures that live side by side. They both have a whitish colored 'stalk' about the diameter of a string bean and is about 1/2" long. On top of the stalk is a brownish colored slightly concave disk about the size of a dime, or maybe just a bit smaller. The edge of the disk is lined with tiny hair like projections that radiate straight out and are about 1/2 mm long. These creatures are both basically resting against the soft coral, and don't' react to much. <A zoanthid of some sort probably> The other is a mysterious set of brown tentacles that appears now and then from a small piece of live rock. The tentacles are dark brown, about 1/4" long or maybe a little more and taper to fine tips. Is this the dreaded Aiptasia?? <Maybe... but if stays in own place w/o reproducing out of control, not so dreaded/ful> Any ideas what these two things could be, and should I remove them? <I'd ignore both for now> Thank you in advance. <Be chatting. Bob Fenner>

Zoanthid-eating snail? To Mr. Fenner, I have a question that no one else seems to be able to answer. I am sure your are familiar with the snail that is parasitic to zoanthids. I believe it sucks them dry. I have had these snails before come on colony rocks of zoanthids so I am familiar with what they look like. I have a nocturnal snail in my tank which I believe to multiplying at a very fast rate. I originally saw 3 or 4 now I can easily count over a hundred. It has been several months since I have been trying to find out what they are. They only come out at night. The largest one being about a quarter inch long. They look extremely similar to the snail that attacks the zoanthids except there have brown markings on their shell. I have been told that the zoanthid snail will not multiply in the aquarium and I am almost certain this one is at a fairly fast rate. I also have many zoanthids in my tank and theses snails only seem to forage amongst the rock and the glass. I even put several on my zoanthid colonies only to watch the snail wonder away. Any help would be appreciated. In my tank I also have red footed snails, Turbos, some chiton that have since multiplied, burrowing snails which have also multiplied. Thank you , Ryan Alexaki <Hmm, I do know that there are several species of snails that predate zoanthids... and am way past due on updating, identifying and putting images to these parts of books in/to be in print and the www.WetWebMedia.com website. Don't know what species you may have here at this point... and in the updating process I'll hope to find out. Please keep reminding me if I don't get to this job in the next few weeks. Bob Fenner>

Zoanthids hi bob, it me again. sorry to consult you again. it not that I ask too much question. it because previously I got no one to consult until I got to know you. <Hopefully also reference works, listservs, other sites on the web...> I had brought some button polyped and yellow polyped. According to what you say zoanthids are consider hardy species. <Most> but the button polyped that I previously brought is consider quite big in size. 3-4 week later, the size decreases. <Typical, not to worry> The water condition is ok. and I do not know the reason why it decrease in size. same apply to my yellow polyped. the number of yellow polyped had decrease. Q1. I had placed the button polyped on the aquarium floor and with light. the current is consider medium low. Is the placement correct ? Q2. Is the feeding the same as mushroom. If water condition is good, the it is not necessary to feed the polyped ? Q3. What is the cause of the reducing of size ? <Likely just adjusting to the conditions, newness of their new home... I would feed the polyps... as detailed on the site: www.WetWebMedia.com> * Anyway do you have book which talk about the detail about corals (environment it is found, lighting requirement, water current and more details) If have what is the name of the book. As I am staying in Singapore and marine aquarium is not so common here. It hardy to find lot of marine aquarium book here. Do you have any web site to recommend if I want to know more about the coral ? Thank again. Danny C. <Will be visiting SG in May and June... And yes to helping you help yourself with a suggested book or two. For sure you want to devour "The Modern Coral Reef Aquarium" by Fossa and Nielsen (their link is on the WWM links page) especially volume 1, and v.1 of the Baensch "Marine Atlas". You will greatly enjoy these books, and benefit from them. Bob Fenner>

Zoanthids in Japan  Dear Mr. Fenner, Hello - my name is Jamie Reimer and I am a Canadian graduate student at Kagoshima University studying Zoanthids in southern Kyushu, Japan. I have been working with a Zoanthid species for 2 years now, and I am still having problems identifying it down to the species. I picked up your e-mail address from the wetwebmedia.com site as I was trying (unsuccessfully) to ID my species. Anyways, I wanted to ask if you or anyone you know could point me in the right direction as to IDing this species.... as you can imagine, access to English books over here is a bit limited... Thanks for your time, sincerely, Jamie Reimer <Will send your query along to the ever-so astute stony coral (though I know that these are not of that Order...) taxonomists Douglas Fenner and J. Veron for their in turn referring you to up-to-date help. Am surprised that you have not (or don't mention) finding current researchers names, whereabouts that might be able to help you through a literature search... Do you have BIOSIS, Zoological Abstracts online there? Hmm, be chatting. Bob Fenner>

Polyps not opening and snail development The polyps in my tank have stopped opening up all the way. But the two anemones in the tank are opening up fine. My specific gravity is 1.025, my ammonia is 0, nitrite is 0 and nitrate is low. Temp is 80. the lighting comes from a pair of power compacts, one day and one blue.  Could it be that the lighting is too strong?  <No> Or is it the pH?  <I doubt it> My pH test had expired, is it still good to use? <Probably> The fish seem to be doing fine.  <No doubt> One more question? How long does it take turbo snails to develop?  <Develop? You mean to get bigger? Should be continuous, linear with time> My tank is covered in mini snails, but they don't seem to be moving? <Probably not what they appear to be> >> There is likely a negative interaction between your Anemones and polyps... I would institute monthly use of a chemical filtrant (like activated carbon) in the filter flow path... and do a large (25%) water change in the meanwhile. Bob Fenner

Green Button Polyp Problem I know green button polyps are supposed to be some of the hardiest polyps  around, but I am having some trouble with mine even though I have gorgonians  which are supposed to be difficult but are doing well. I have a 400W MH over  a 2ft deep 90gal tank the button polyps are on the bottom. The polyps are  multiplying and their are very healthy ones next to some that appear to be  burned with some white spots and signs of dissolving. What could this be  from? I do frequent water changes 20% every other week. Chemical tests are  normal no ammonia, nitrite or nitrate. I also have some green star polyps  that are not faring well the mat has receded a lot. Could their be hydrogen  sulfide pockets in my tank and how do you test for this? >> May be a biochemical reaction/competition with some other life form in your system... too much light... some sort of additive/supplement poisoning.... If there were sufficient H2S in your system, you'd smell it, see the blackening in your substrate, see bubbles coming out of it from anaerobic glycolysis... What I would do with the button polyps (zoanthids), is move some of the colonies off to the sides (out of the direct blast of the MH(s)... and add a unit of Polyfilter, and Chemipure to your filter flow path... and take a long look at your supplement habits. Bob Fenner 

Star Polyps I have a 55 gallon tank that has been up for about 11/2 months. Everything  in the tank is doing great (polyps, mushrooms, clownfish, Firefish, &  different kinds of shrimp) except for one rock of star polyps. I've tried  moving it around the tank and it doesn't seem to be helping. They used to  come out. There are still about four stray polyps on the lower side of the  rock that come out, but that's it. Do you know what could have happened  and how to fix it? Nicki Kubes >> Hmm, might be a case of biochemical fighting between the polypoid species... or maybe an iodine deficiency (do you add this as a supplement?)... If it were me, I'd keep them in a well lit, well circulated area away from the mushrooms, and add a unit of activated carbon in your filter flow path... to help in reducing metabolite poisoning. Otherwise... wait and watch... Bob Fenner

Question: Thanks for the info. on bristle worms and green brittle stars. Just a question about a colony of brown star polyps I have in my tank. I have 55g. system w/ 4 fish.( two yellow tangs, a regal tang and a blue damsel.) I also have various crabs, snails , etc. The tank is lit by 160 W of fluorescent light and the bulbs are all new within the last six months. I have a colony of green and red mushrooms in there also which is doing great, it expands well and new mushrooms are sprouting. The brown polyps on the other hand are going the other direction. When I placed them in the tank about 3 months ago they did great. They opened up well and even appeared to be spreading. In the last two weeks, fewer and fewer polyps are coming out and as of today they are little more than bumps with hardly anything showing. I have done some water changes and have even started to run a Magnum filter with carbon. Nothing appears to be working. My next thought was to change the position of the colony in the tank. I don't overfeed and my nitrates are at about 20ppm NO3. What gets me is how the mushrooms, which I understand have similar requirements, are thriving while the polyps are dying. Any help you can offer would be appreciated. Bob's Answer: Hey Roman. Well you're right on target with moving the Polyps. Very likely they're under-circulated and very very likely involved in chemical warfare with the seemingly acquiescent mushrooms. Those corallimorpharians are actually quite virulent in their campaign to take over all available hard space, and you'd do well to arrange "breaks" or demilitarized zones to prevent their spread/proximity to other stinging celled organisms. Place the brown polyps above, away from the corallimorphs my friend.