FAQs about Xeniid Pests, Predators, Social Disease FAQs on Xeniid Disease: Xeniid Disease 1, Xeniid Health 2, Xeniid Health 3, Xeniid Hlth./Pests 4, Xeniid Hlth./Pests 5, Xeniid Hlth./Pests 6, Xeniid Hlth./Pests FAQs on Xeniid Disease by Category: Diagnosis, Environment, Nutritional, Pathogenic (Infectious, parasitic), Trauma, Genetic, Treatments Related Articles: Pulsing Soft Corals, Family Xeniidae,  Related FAQs: Xeniid FAQs 1, Xeniid FAQs 2, Xeniid FAQs 3, Xeniid FAQs 4, Xeniid ID, Xeniid Behavior, Xeniid Selection, Xeniid Compatibility, Xeniid Systems, Xeniid Feeding, Xeniid Reproduction, Soft Coral Propagation, Soft Coral Health,  Alcyoniids, Nephtheids, Dendronephthya, Paralcyoniids, Nidaliids,

Xeniids generally lose to more aggressive Cnidarian groups in allelopathogenic interactions

Pulsing Xenia "hands" missing   6/14/10 Hi there. I have a Pulsing Xenia that I got from a LFS. It was thin and tiny when I first got it. I noticed that around a few of the "hands" there is a white spot and there are a few missing. <Mmm, you may want to remove the white spot... or take a large, well-resolved photograph... "blow it up" on your computer and look... This could be a pest, likely a Nudibranch predator> The tips where the hands are missing are white. It is still pulsing and little hands are still growing out. I was wondering what is causing this. <Use the search tool, http://wetwebmedia.com/Googlesearch.htm with the string: xeniid+predator read the cached views with the highlighted string> Do they propagate this way or is there a predator that I have not found? <Likely the latter> It still looks healthy though. I have it on a frag shelf up in the upper part of the tank. So I am not sure what could be bothering it. I have 2 clowns, 2 orange lined cardinals, snail, hermits, <Could be these> and some corals. Corals are mushrooms, toadstool, star polyp, frog spawn, and some Zoas. I have another question. My Pom Pom xenia is not pulsing. I have had it only 2 weeks. What causes them not to pulse. <... see WWM re> I got it from LiveAquaria. If you need anymore information let me know. I would appreciate any help. Thanks you guys are the best. Patty <Bob Fenner> Pulsing Xenia "hands" missing with picture   6/14/10 I have a Pulsing Xenia that I got from a LFS about 3 months ago. It was thin and tiny when I first got it. Now it is much fuller. I noticed that around a few of the "hands" there is a white spot and there are a few missing. <I see in the pic... maybe the Acanthurus leucosternon here nibbling...> I know Bob said to cut out the white spots but as the picture shows it is right below the hands and there would be little left. It is as if the hands are slowly constricting and then falling off. <Oh... then could be a chemical anomaly... as alluded to previously. Did you read where you were referred?> I have looked for a Nudi and have not seen any. I also have been looking for any movement around the rock. My hermits can't reach the rock on the shelf. The one inhabitant I forgot to mention is a pincushion urchin. Could this be nibbling? <Nah> But wouldn't it just bite them off? I am willing to cut but am afraid there would be no hands left ;). Again any help would be great. I hope the pic helps. It shows the xenia on the shelf and you can see the white areas before the hands and even some where the hands are missing. This is why I thought maybe it was a reproduction thing. I am at a loss. Thanks a million. The website rocks Patty <Read. B>

Re: Pulsing Xenia "hands" missing with picture  6/14/10 I don't have tangs. <Ahh! The pic you sent has something suggesting this> I only have 2 clown and put in 2 cardinal after quarantine (This started before I added the cardinal) I was told it might have been a predatory Nudi. <... as I originally stated...> I have been reading about predators and xenia. I have been looking. But have not seen anything yet. What chemical anomaly do you think? <... please stop writing, and read> I have been reading other xenia info as well. Thanks for getting back so quickly. Sorry I am being a pain but just a little confused. I don't want to have my xenia have problems. I love it. Patty <... B>

Re: Hungry Shag Rug Nudibranch? What?  2/23/2010 I had to throw the rock out it was rotting the tank and made the tank smell rotten. <What? No; should have been cured elsewhere. Read: http://wetwebmedia.com/lrcurefaqs.htm> I'm still trying to get my nitrates down <... see WWM re> from it <What is "it?"> looked like a flower with petals but after closer examination I saw antlers or whatever and when touched the "petals" fell off. what really sucked was the LFS said "too bad we cant catch every thing" and to toss it before it spread so I was just SOL Thanks for your response though. Kris <... Fish out of luck? Kris, please proof your writing before sending. I can't make out what you're trying to state here, nor what you're trying to get at with the too-large images you've attached. BobF>

Re: Hungry Shag Rug Nudibranch  2/24/10 Sorry about my writing I was never good in English. <Please... take your time. Re-read over what you write... perhaps show it to someone else before sending> Anyways the pics were to show the Xenia when I purchased the rock or colony within 2 weeks this creature had destroyed the whole thing and I had to throw the rock out. <Wow!> It was the Xenia that smelled rotten not the rock. I'm just hoping the Nudibranch didn't lay eggs. <I do too> Thanks for your responses Kris <Thank you for this clarification. BobF>

Hungry Shag Rug Nudibranch, Xeniid pred.    2/8/10
Hi Crew:
I hope you can help. Two weeks ago I purchased a Xenia rock with approximately ten or so stalks, the next day they started to die off. I went into the store and they told me that the Xenia is temperamental
<Can be; esp. when moved... to "differing circumstances">
and to try an Iodine cleanse which I did. I examined the rock and found what I thought was an Anemone but not sure what kind and it was eating the Xenia . Through internet research I found it to be a shag rug Nudibranch.
<Aeolidia papillosa? I doubt this is the species here... This is a cold-water animal. Could well be something very similar however that is tropical>
how can I destroy it I before it goes on to something else?
<Yes... I would siphon it/them out, or use a pair of long tongs to extract>
I do like the Xenia and it has destroyed about 90% of the rock.
Thank you for any help and answers you can give it is much appreciated
Kris
<Could you send along a few close-up pix Kris? Bob Fenner>

Completely stumped - soft coral problems, allelopathy, Ozone option  06/02/09
Hello,
<Hi there Ken>
I need some help as I'm completely stumped, I have been running a 90 G tank for over 10 years now. Some good years some bad.
Currently I have for the last year been able to keep the system running with 0 Nitrate's as I had major nitrate problems.
I had been running with CC substrate and trickle filter with a small skimmer (old school! ) with 275W of PC lighting So I had changed up the system over a year ago upgraded to a Euro Reef RS135 running in a 30G sump with a 15G fug. and CaribSea reef floor sand. Also upgraded to 8x54W T5's
So currently I have 140 Lbs of rock (been in use 10 years)
<Mmm, I'd be adding a bit new to this. Please see here:
http://wetwebmedia.com/substrepl2.htm>
with a total of 125g of water in the system.
I do a 20G water change every 2-3 weeks (just timing issue) and dose BRS two part daily.
Current parameters - that I test
1.025 Salinity - Refractometer (checked and tested at LFS)
80 F Temp - digital
8.4 (night) - 8.5 PH (day) - using Vital Sign handheld calibrated last week
8 DKH- using API
430 Cal - using Seachem
1300 Mag - using Seachem
0 Ammonia - using API
0 Nitrite - using API
0 Nitrate - using API
0.01 Phos- Using Elos
0.06 Iodine - using Seachem
Here is my problem all of my pulsing Xenia for the last few weeks have all stopped pulsing, their white body's have gone from white to dark brown/pink (best I can come up with LOL) I had a frag in the
tank 6 months ago that got stung by my Ritteri anemone ( I know small tank for a Ritteri but love them so much) so I moved it and it started to grow back and kind of stopped growing. I got a another frag and it grew to three times it's size and picked up another frag for my small tank that was cycling and it to grew to three times it's size quickly. then the first frag has started to shrink and turn dark and now the second frag
is tuning dark and not coming out fully. At the same time (about 6 months ago) I had picked up a green orange clove polyp frag and it too started off strong went from 5 polyps to 25 and now it too has stopped growing. Some of the polyps will not open fully and they look burned (the edges are white)
My mushrooms are not expanding fully but look OK, my Leather is OK, my Zoo's are OK, All my LSP and one SPS are doing good (still growing) even my Acans are fine, so what gives?? What I'm I missing??
<Mmm... perhaps... some general aspect of water quality that would "save" your "losing" Cnidarians from apparent allelopathy... A bunch to speculate here... But let's start by having you review:
http://wetwebmedia.com/cnidcompppt.htm
and the linked files of this ppt. condensation, and then a bit re RedOx...
which, better than "stooping" to more expensive chemical filtrant use...
I'd look into... Ozone use... perhaps with a desiccator:
http://wetwebmedia.com/redox.htm
and http://wetwebmedia.com/SystemPIX/RedOx/RedoxPPTpres1.htm
and the linked files...>
Thanks' for any help or direction you can offer.
If I left out any needed info please let me know.
Ken
<Again, Ken, there are a few avenues you might consider, go here... For me, a cursory reading/understanding of the negative interactions of the life you list and a short/sure method of "curing" these processes is likely to be satisfying. Bob Fenner>
Re: Completely stumped - soft coral problems  6/2/09
Hello Bob,
Thanks for the insight, It is not the first time I have thought or have it been suggested to replace some rock. I had almost at one point the intention adding some new rock and cooking the rest on a rotation bases. My still end up going that way, but after I managed to get the nitrates under control did not think it was necessary.
<Does really help>
As for the latter ORP, this also came up in the past when fighting nitrates I tried vodka dosing for organic carbon to help consume the nitrates but found no positive effect, when dosing my star polyps stopped coming out and my leather did not seam to like it either, as well the nitrates held steady. It was suggest to check ORP at that time, but I played with my fug slowing down the flow from ~300g/hr to ~100g/hr and this helped knock the nitrates down. This seamed to me to prove I have a lot of oxygen and by slowing down the flow helped the 6" deep sand bed and Chaeto do its thing.
But I'm just a hobbyist taking my best guess from over information and not enough understanding.
<We share this trait>
I believe my next best hope is to check ORP and see if the problem is there.
<Do see my bits on WWM re... you really want high, consistent readings (375-400 micro Siemens/cm)>
The one thing I have learned in this hobby is when you think you know what your doing and your reef is doing great, it just pure dumb ass luck!
<Mmm, not entirely in my experience>
and the next adventure is just around the corner.
Again thanks' for the input.
Ken
<Glad to share. BobF>

Stowaway Nudibranch, Xeniid pred.  04/20/09 Hi crew :D I recently bought a lovely colony of red sea xenia which was home to a Phyllodesmium hyalinum - the little Nudibranch fell off the colony when it was knocked off the rock work. While this may sound a bit sad I know, the little guy is rather lovely and although I have no wish for it to snaffle my xenia I'd like to know if I can help it to survive, short of putting it back on the xenia colony... <If it is indeed a Xenia eating Nudibranch, chances are that it needs to eat Xenia in order to survive. However, you might be able to feed it any kind of Xenia. Thus, you might be able to set up a little biotope for it and just feed it xenia frags (if you can find such for cheap). The other option, you could ask your fellow reef aquarists if they have excess Xenia (many reef keepers do-- some even consider the coral a pest at some point).> after all, I did purchase the animal albeit accidentally! <I do sympathize, appreciate your sentiment here. I recall a friend of mine who fell so much in love with two beautiful Nudibranchs that hitchhiked on his sun corals, that he forgot about the sun coral and did everything he could to keep the slugs alive by buying dying sun corals from LFSs, just to feed them. Of course, I don't recommend this per se, but I do sympathize with any such love for Nudibranchs. I've also had them as hitch-hikers and always wished I could keep them. However, do know that these animals don't usually live that long (even in the wild).> Will the Nudibranch ultimately cause the death of the xenia, or will its feeding habits do little more than limit the size of the colony? <Well, firstly, please do send in a pic so that we can confirm that this is a Xenia eating Nudibranch. Secondly, *one* Nudibranch on a large, fast-growing Xenia colony, might not destroy the colony, but as you say, just keep it "mowed" a bit. The trouble is that the Nudibranch could likely reproduce. Within a short time, you might not just be dealing with one Nudibranch, but many many Nudibranchs... who would likely destroy the colony eventually.> Many thanks, Carolyn <De nada, Sara M.> Re: stowaway Nudibranch 04/21/09 Hi Sara, Many thanks for the reply - have attached a picture of the little guy. <Wow, great pic! May I ask, what camera did you use? The slug does look like a Phyllodesmium hyalinum. Please see here: http://www.seaslugforum.net/display.cfm?id=13207 You might even want to write in to this site with your story/pics, since it is noted to be very difficult to find/see in the wild. Thus, maybe Bill Rudman would get a kick out of seeing yours (or at least confirm the ID).> Carolyn <Cheers, Sara M.>

Xenia (pest?) and worm (ID, comp.)    2/20/09 Hi. I'd like to thank you for all your help. Today I noticed that one xenia colony has brown/black specks crawling all over it. <Mmmm> Just a few days ago a crab reproduced, so I wonder if it could be crabs eating away at the xenias. I say eating because some of the branches look like tiny parts are missing. If it is not tiny crabs, what else could they be? <Small crustaceans... or Nudibranchs... or... Need a much higher resolved image or two to tell. There are treatments for all... see here: http://wetwebmedia.com/LR,LS/HH%20PPT%20Pitch%20Cells/HHProsConsart.htm> Is there anything I need to worry about? We have two xenia colonies and only one shows the spots. I have attached a few pictures. <If it is convenient, easy to do, I would move the one showing these moving zots to another system... carefully lift it and place it in a container underwater... so that if this is a pest, predator it doesn't fall off...> When I was checking on the xenias, this yellow worm was stuck to the glass. I did some research and it looks like it could be a spaghetti or medusa worm. Can you confirm which one it is. Is it harmless in my tank? <Should be... it is almost assuredly a species of Errantiate Polychaete, see the Net re... Perhaps a member of the family Cirratulidae> I have removed it from the tank temporarily until I learn more about it. Thanks for all your wonderful help. Cindy salinity 1.025 nitrite 0 ammonia < .25 nitrate 2.5 ph 8.4 Alk 1.7 - 2.8 <Bob Fenner>

Xenia Trouble...? - 05/31/08 Hello Crew, <Michael> I have a question about my (Regular) Pulsing Xenia. I have had my tank up and running for about 2 1/2 months and I have had my Xenia in there pretty much since my take was established. The Xenia has been doing great, I have propagated it several times with successful results. The other week, I moved the rock because it was too close to the glass. Since then one of the stalks was rubbing against another piece of live rock (I thought nothing of it). Now, that same stalk looks like it is dying all the polyp types have turned white, many have disintegrated and it seems like it is spreading to the other stalks that are near-by. Any ideas what has caused this? <Mmm, yes...> Have you folks heard of this situation before? <Quite often> Will the rest of my live stock be harmed? <Only if the water becomes polluted. Likely only the Xenia will perish> I have about $3,000 in other coral specimens in my tank, including Blue Xenia. <!? In 2.5 mo.s!?> The blue Xenia doesn't really pulse very much, but I have the smaller white color Xenia and it is still pulsing like crazy, as are the other specimens of (regular xenia). I just completed a 10g water change, have not checked the levels yet, I know that Xenia is pretty finicky when it comes to the water conditions. But all my other corals are thriving, so I am not sure why the (regular) Xenia is going downhill, but it seems like every other coral is doing well. That would lead me to believe that the water may not be the problem? <Sometimes pulsing corals do "crash" population wise... can be triggered by part of a colony's distress, dying... There's not much to do to stop this... other than moving parts of the colonies elsewhere> Please Let me know if you have any ideas or what actions I should take.. A little about my tank, it is a Custom built 75 gallon (L36"xH24"xW20") <With 3k in livestock?> fully built reef system with built in refugium, I have 4 blue/green Chromis, 6-line wrasse, Dragon Goby, Coral Beauty, Hermit Crabs/snails, Yellow Stripe maroon Clown, Rose BTA, <... trouble with other Cnidarians in such a new system of small volume> Lighting is provided by a Current Orbit Series (150w MH, 2x 96w Actinic, 4 LEDs) Best Regards, Mike, So-Cali <... read here: http://wetwebmedia.com/cnidcompppt.htm Bob Fenner>

G'day, Sudden Xenia crash... Cnid. incomp.    2/8/08 Good morning to all at WWM, I have had several Salt tanks for a few years now. All of them have always had pulsing Xenia in them. The tank in question is a 72g BF with a 30 gallon sump, 2x250 MH, 4x54 T5 actinic, Mainly Softies and LPS. <Mmmm> This tank has been setup for a little over 2 years and has had pulsing Xenia in it from the start of adding corals. I haven't added anything new in quite some time I don't even remember when it was but it's been a while. I do however frag/trim stuff fairly often to keep from overgrowing. Tank Parameters SG 1.025-26 Temp 79.8 - 81.1 Nitrate 20 Ammonia 0Nitrite 0Ca 350Mg 13202% - 5% water change every couple of days (I'm a stay at home dad so I like to work on the tank). Okay all that said I woke up yesterday morning, looked at the tank and saw that the pulsing Xenia Had shriveled up drastically more than I'd ever seen it. The tops were turning a light white/green color, also if you moved them at all they let off a dark brown stuff into the water and They smell really bad. I have always kept them isolated to one rock in the tank and trim them down when it gets to big. I usually keep what I trim off in the sump or give them away. The odd thing is that all the Xenia in the sump are doing the same thing! <Mmm, not strange> But no other corals seem to be effected by this. I have attached some pictures of the Xenia in question, <Good ones too> as well as some shots I took just two days ago. I guess my questions are, Is there any hope for them still or are they gone? <Gone> Is it bad to leave them in the tank to see if they make it? <Likely no trouble... are being dissolved, filtered out...> What could do this to them so suddenly, could it have been some kind of chemical warfare, <Yes> the only thing near the rock is a Torch coral, GSP, Toadstool leather? Thanks again, Never could have made it this far into the hobby without everyone's help at this site! Lucas <There was some sort of "cascade effect" by one, two of the above Cnidarians... Likely the Euphyllia... and...? The Xeniid lost. Bob Fenner>

Xenia shriveling  1/16/08 Hi crew! It's been awhile since I've had any problems but now my xenias are dying. They've been in the tank for 5 months and were doing great. They were spreading and still are. I had 3 large stalks. The first one shriveled but is not completely dead. Then the 2nd within 2 days went from straight up and strong to shrinking, twisting and falling over but it is still trying to pulse. <A good sign> The 3rd one is going strong. I moved the powerhead so they are not getting as much current as they were. I scoured the website and checked the ph and alkalinity as advised. <Yes> Both were low (ph 8.2 and 8 dKH). <This is not low...> I corrected that and now the ph is 8.3 and the alkalinity is 10. However that has not changed their status. I thought I had read that other corals could affect them as well. <Yes> I also have green Zoanthids and green Ricordea mushrooms. <Have these been "upset" or challenged recently... they/either could malaffect pulsing soft corals> Where in relation to the xenia should those be placed? <Away... and more... chemically... and...> I originally had both lower than the xenia in the tank but moved the Zoanthids for lighting purposes. Could this be the problem? <Ah, yes> What else could be affecting the xenia? <A myriad of possibilities... Do you dose with an iodine/ate compound?> I have a 55 gal with 130 watts of lighting. Thank you for your help! Jennifer <Please peruse here: http://wetwebmedia.com/cnidcompppt.htm and here: http://wetwebmedia.com/xeniiddisfaq3.htm and the linked files above. Bob Fenner> Re: Xenia shriveling 1/17/08 Hi Mr. Fenner! I just started adding iodine at 1/2 strength until the testing kit comes in. Also, I moved the Zoanthids farther away and lower. Thank you for your response, also I'll look at the referred links. Thanks again Bob! Jennifer <Welcome Jen! BobF> Re: Xenia shriveling, and FOWLR stkg.  1/17/08 Bob, xenias seem to be doing better since I moved the Zoanthids. I do have another question. I've been researching obtaining another fish and want to make the best choice for my current inhabitants, whom I very fond of, and for the fish I purchase. Currently in my 55 gal I have a tank raised clown (he's the boss-2 years old), 1 Firefish, 1 coral beauty, 1 royal Gramma, 1 Chromis, 1 sleeper goby, 1 coral banded shrimp (4"), 1 Echinaster spinosa (sp?) starfish, 5 hermit crabs, 3 limpets and 2 conchs. I researched on WWM Butterflyfish, which seem to be the most compatible, Hawkfish (could be problem with shrimp) and a yellow tang. Some of the research on yellow tangs said 55 gal is too small and some says it's ok. What is your opinion? <It's borderline...> I do not want an unhappy fish. Or do you think I've hit the bioload for this tank? Thank you again, Mr. Fenner! Jennifer <Jen... I do think you are "about there" re psychological limit with the fish species you list. Bob Fenner>

Xenia Tube-Pest  9/26/07 Hey All, <Hi Ted> I have an unidentified pest eating my xenia elongata and occasionally my pom-pom xenia. It seems to live inside the rock on which the xenia have attached. I have not seen the pest itself but it forms almost translucent fibrous tube with bits of sand leading to where it has eaten. If I destroy the tube or block up the hole, it will return within a day to a few weeks. It has appeared only on one other rock but quickly disappeared without xenia nearby to munch on. I have not tried to chemically treat the holes (similar to Aiptasia treatments) because I don't know with what I am dealing and do not want any collateral damage to the xenia. <Very strange... any chance you can get a picture?> Thanks for All of Your Help Ted <Best, Sara M.>

Xeniid Help RESEND 4/12/07 Hi all! I am sending this again via webmail to see if it makes it this time. No response first time around (Those web gods!!) <Thank you for this. Your first go "kind of" made it... but "trayless"... the short expl.: we'd have to re-send it through our system to respond...> I am an avid reader of your site and have been known to spend hours upon hours researching for the answers to many of my questions, most of the time with success; however, this one has me stumped. First the tank specs: TANK SPECS: 29 Gal BC with additional "baby powerhead" and external skimmer Salinity 1.26 pH Stable at 8.4 (taken consistently at 4:30 AM with pH monitor) Temp 79.4 day / 78.6 night Salifert test kit results: Calcium 460 Alk 13 dKH Ammonia 0 Nitrite 0 Nitrate > 5 Phosphate 0 I am currently using a PolyFilter and Chemi-Pure in case of chemical warfare <Okay... though these are more useful for inorganics...> RESIDENTS: 2 cleaner shrimp 1 fire shrimp One 1.5 inch maroon clown and one 2 inch yellow tang <Mmm...> (until they are big enough not to be eaten by V lion in the 240 gal) Presumed mantis shrimp due to skinned/diced Mandarin <Also mis-placed in such a small volume> (which was trained to eat frozen as well as flake food and was FAT), another story entirely¦ CORAL: Open brain Candy cane Torch Leather toadstool Finger leather Mushrooms Xenia which are at the top of the tank by water return and far away from any of my LPS and softies (which are still thriving) <A clue here> PROBLEM: My Xenia had been thriving for about four months now growing from three stalks to approximately 20 in this same time period; that is until five days ago, at which point they have been only bulbs which are now slowly deteriorating. I have been doing consistent 5 gal water changes every other day upon discovering this until two days ago when I upped it to 5 gal every day. I have even taken an 8 oz glass with tank water and added 1 drop Lugol's and gently poured it on the Xenia with no success (only once). I am wondering if there is some macroalgae growing within the Xenia stalks which may be the culprit. <Mmm, likely "after the fact"... but... are you sure this is an algae? Might be a Hydroid pictured here...> I have enclosed a picture which I hope you get. If not let me attempt to describe these things. They are long rigid stalks with a feather tip only, dark green in color and approximately 1 to 2 inches in length) They are very stubborn as I tried to tweeze one out thinking it was a human hair entangled within the Xenia and it did not break or budge!?!?!?!? <Bingo> I have no idea what these things are but if this is in fact macroalgae then do I just tweeze these pieces, or cut them with scissors? <May take more drastic action here... the cleaving of the Xeniid colony, scrubbing around the bases of the salvaged polyps...> Once again I have no idea what I am seeing or dealing with or if it is even a problem and the real problem lies elsewhere. Any insight would be greatly appreciated <Is something other than algae... a look through a microscope would help here... I'd remove the colony, clean out these pests, try to restore the pulsing corals health in isolation. Bob Fenner>

Re: Xeniid Help RESEND, hydroid ID 4/13/07 Mr. Fenner, <Kim!> I am honored to have you reply to my email; thank you. <Welcome... Geez, I must be getting old/er...> I would have never even thought hydroid as I always associated this with a very minute "thing with tentacles", but after doing more research and comparing pictures with what I have, I am in complete agreement. Looks a lot like Antennellopsis sp. <Possibly> I promptly removed the Xenia and scrubbed the areas that I could and took needle nose pliers to those buggers since the tweezers proved to be of no help. I managed to remove all that I could see plus the dead and dying Xenia stalks and now I will wait and see what happens. <Good> I feel bad that I was thinking environmental cause (reason for overkill with the PolyFilter, Chemi-pure, and extensive water changes) and my poor Xenia were being stung the whole time (I visualize myself being locked in a car with bees for a week). One more lesson learned to lock away in my head. <Mmm, not locked... but shared, released to other possibilities> As an aside, I would never even think of keeping my clown and tang in an environment this small for any extended length of time; however, the last attempt to add juvenile fish with the lion proved to be an expensive meal for the lion and a month to retrain him to eat prepared food again. These two fish are still smaller than my cleaner shrimp and I am sure would be consumed within one day by the lion if given the chance (lion is a good 6-8 inches). <Yikes> I do have a spare 55 gallon lying around that I could set up to "grow out these toddlers" if you feel this would be more appropriate. I really respect your opinion and thank you again for your keen insight. Have a Great Day! Kimberly <Ah, from the tenor and apparent intelligence of your writing, I fully suspect you are more than capable of "making the call" here re the observable behavior of these two and their need to be re-situated. Bob Fenner>

Re: Xeniid Help....HYDROIDS HAPPY UPDATE -- 4/28/07 Hello to all and thank you again for being there!! I have placed a copy of our previous correspondence below for reference. <Thank you for this> I wanted to let you know that because of your (Mr. Fenner's) ability to teach me something new my Xenia are back on track with new babies everywhere!! I am certain they would have died without your 100% accurate assessment, diagnosis, and treatment recommendations (which I followed to the letter) as I was treating for everything BUT hydroids and they kept going downhill. I have enclosed pictures of their incredible recovery!! (It has only been two weeks since their near death experience). Thank you again SO much for being there, you saved another life! If there is anything I can do to help you out in return, it would be my pleasure!! Kimberly <Thank you for sharing the news of your success. Bob Fenner>

Why Can't I Grow Xenia? -- 02/21/07 Greetings, <<Hello>> I am having a problem with pulsing xenia. <<Not uncommon...some folks can't grow it...some folks have trouble getting rid of it...and sooner or later it all seems to just 'crash'>> Located in 30-gal tall octagonal tank attached to a 75 gal reef tank.  The octagonal tank has only a mated pair of mandarins, macroalgae and I had a large colt coral. <<Mmm, this last may be part of your problem...very noxious>> The xenia all of a sudden looked awful.  It took me a week to find the time to test the water...  Tested my pH and it was low for xenia, 8.0.  I immediately did a water change and after about 24 hours got the pH back to 8.3. Xenia looked better this morning and I got home from work tonight and it looks awful again.  I also decided to move the colt coral to the main tank. <<A good decision...although, with these tanks 'attached' the noxious chemicals exuded by the colt coral are still in the system water reaching the xenia>> Salinity 1.024, <<1.025/26 (closer to NSW) would be better appreciated by your corals and may be another factor re your problems here>> Temp 78-80, the pH is usually 8.3 but I did find it close to 8.0 two days ago before lights went on. <<I wouldn't think this to be much of an issue>> I am not sure why.  I drip Kalkwasser most nights (about 1gal) and had not for a few busy nights.  Never a problem in the past but concerned me the other day. <<When using this methodology, it is best to use on a 'continuous' basis for reasons of system stability...as you can see>> Ammonia and nitrates 0.  No way to test iodine so I started putting in 2m. each morning to help them out. <<2 milliliters?  Do be careful here...be sure to follow the manufacturer's instructions closely...and get an iodine test kit>> The pulsing xenia look shriveled and almost like a chemical burn might seem to look if that does not sound too crazy. <<Not crazy...and may very well be so (remember that colt coral)>> Can you suggest some test I might perform. <<Not for allelopathy...but make no mistake, it is present in your (everyone's) system>> Why do you think I have such problems with pulsing xenia. <<Aside from the fact that these organisms seem to 'wax and wane' with the best of care,  xenia can be particularly sensitive to water chemistry/ chemical poisoning (some aquarists have stated to me they view their xenia as a kind of 'canary in the mine.'  Employing some purposeful chemical filtration will always help your system, and may make a difference with the xenia.  A dedicated canister filter with carbon 'and' Poly-Filter is highly recommended here>> I have a wonderful 75-gal reef tank with hard and soft corals.  All doing fine. <<And all 'fighting the chemical fight'...just likely more resilient mix of organisms than the xenia>> I know you are not supposed to mix but for 3 years I have been lucky I even (was afraid to admit) have a bubble anemone (3 years old) with clowns, Regal tang, Pseudochromis, Sailfin blenny, Ricordea, mushrooms, frogspawn, gorgonian, Zoanthids, dish coral, and star polyps. and Acropora. <<Mmm, indeed...I wish you continued good luck>> The hard corals are at one end and soft at another and it has worked out well so far.  Can you suggest any problem with xenia.  This is actually my third try. <<Ideally, separate the xenia system from the mixed garden reef system...else employ/add more chemical filtration to mitigate the effects of the chemical aggression.  And read here, among the associated links to get more info re others experience/opinions with this organism: http://www.wetwebmedia.com/xeniidfaqs2.htm And maybe do a Google search on our site re 'chemical aggression' and 'allelopathy.'  Regards, EricR>>

Xenia disappearance   8/11/06 Hi Crew, <Tom> Overnight, it looks like one of the main stems of my month-old Xenia disappeared, leaving only an attachment stub (that still has two very small new "sprouts" showing).  Although I see no obvious signs of a struggle, I suspect foul play. <Could be...> Other tank residents include 2 Gobies, 3 Peppermint Shrimp (who did a remarkable job eating my Aiptasia, over the 5 weeks I've had them in there), one Fire shrimp, 3 (supposedly) algae eating Hermit crabs, and one unidentified hitchhiker crab, dime-sized or smaller. <... could be any of the crustaceans... or...> For what it's worth, the tank has also had a Sarcophyton for 9 months, and it has never had any problems. Thanks for your thoughts, Tom <And there are situations in which pulsing soft corals do "just fail"... sometimes quite rapidly. Please read on WWM re the propensity (Compatibility) for each of the crustaceans listed to get along, and here: http://www.wetwebmedia.com/xeniidarts.htm and the linked files above for insight into captive Xeniid Behavior, Systems... Bob Fenner>
Re: Xenia disappearance   8/14/06 Thanks, Bob. <Welcome Tom> I removed all the Peppermint Shrimp, and two hermit crabs (one is unaccounted for, but I have not seen it since I removed the others).  I did notice one of these hermits munching on the stub of the Xenia that first disappeared, but he could have been just cleaning up. <Ah yes> As of today,  I see that I have lost at least one more Xenia stalk, and maybe two.  What seems odd is that the remaining stalks look just fine and very happy, while those that disappear do so almost completely, and at night. <Mmm... good to take a look/see with a small-beamed flashlight... perhaps a predator will be revealed...> There still may be a hitchhiker crab in there, and my next step will be to try to trap him. <Good> Is there any chance the Fire shrimp is the culprit? <Very small, but yes> Do you still think there is a significant probability that these stalks are "melting away" overnight? <Not likely... would all go... and during the day as well as night> In case it matters, the tank is a 30 gallon,  live rock, 192 watts (50/50 actinic/10000K), skimmer, 3 powerheads, bio-wheel filter, set-up for about a year. Do you think I should move this Xenia to a different tank (it's still easy, because it's only attached to the plug it came on)? <Is the easiest, surest thing to do to preserve it... is what I would do> (I'm down to two little stalks left). Thanks again, Tom <Bob Fenner>
Re: Xenia disappearance  - 08/15/06 Thanks, again, Bob. <Welcome Tom> It's 12:30 PM here, and I just came into the darkened room to look at the Xenia.  My light fixture has lunar lights, which were bright enough to just make out the shape of my hitchhiker crab right there, apparently working on the Xenia. <Ah ha!> I decided to grab him and pull him out.  I succeeded, but he took with him the rest of the Xenia stalk he'd been working on. <Arggghhh, the irony!> So now I'm down to one Xenia stalk, but presumably no predators in the tank. Thanks for what proved to be good advice! Tom <Mmm, hopefully your one Xeniid stalk will grow into many> P.S. I wonder why he had no interest in the Sarcophyton. <"Not as tasty"> P.P.S.  I wonder if all the hermits and Peppermint Shrimp can be deemed safe.  I suppose I should give the Xenia time to grow before I experiment. <Good idea. Cheers, BobF>

Xenia On The Decline?  - 06/20/2006 Hey. <Hiya! Scott F. here today!> I have been having problems with my xenias slowly dying off and not growing much lately.  They grew like weeds in my tank for about 2 years and within the last 2 months or so they have not been doing very well.  The only major change I made recently was adding metal halide lighting to my tank (yes I acclimated the corals to the lights slowly)  and I added several new corals (Fungia plate, Frogspawn, Open Brain, Zoanthids) a few months ago. <Could be a bout of allelopathy ("chemical warfare") going on, particularly from the Frogspawn- a very aggressive coral> After doing a little reading on WWM I've decided to try a Polyfilter to see if there something in the water effecting them.   <An excellent chemical filtration media, which can help in removing some of these noxious compounds.> I did a search on PolyFilters on Google and found that there are many Kinds and they vary greatly in price. <I think that you might be mistaken. Polyfilter is a patented, trademarked product manufactured by Poly Bio Marine. There is only one "formula", as far as I know. The pads are available in different sizes and shapes, however. Perhaps you were looking at "polyester filter media"?> I was wondering if you could tell me what type/brand you can recommend and maybe an internet site where I can purchase one. <Again, there is only one Polyfilter. It's available at most e-tailers.> I was also wondering what type of chemicals/water quality issues xenias are more susceptible to than other corals.  All my other corals (Zoo's, Mushrooms, Colt Coral, Frogspawn, Fungia, Gorgonia, Green Star Polyps, Open Brain) are doing well.  Thank you Jon <Well, John, there are a lot of theories about why Xenia does well for some hobbyists and not others. Theories ranging from pH to toxic metals in the water, lack of iodine, as well as water that is "too clean" (I never bought that one, myself) abound. These corals can be susceptible to the chemicals released by competitive corals (i.e.; terpenes, etc.). Be sure to provide adequate space between your corals, lots of good water flow, regular water changes with quality source water, and use of the aforementioned chemical filtration media (like Polyfilter!). The answer is out there, and I think that allelopathy may be playing a role in the apparent demise of your Xenia. Do some careful observing and a little research, and I'll bet that you'll find your answer! Good luck! Regards, Scott F.>

Xenia just vanishes overnight... Cnid. allelopathy  - 5/8/2006 I have been reading your forums for months and have really learned a lot from them!  One thing I can't seem to find is how Xenia can literally disappear in a matter of hours. <Mmm, can/does happen... not much to "pulsing corals" physically... seem to be able to "phagocytose" rapidly under dire consequences, influences> I have a 75 gallon tank with live rock and live sand. There are some hard corals like the pagoda cup, frogspawn, Alveopora and hammer. Also we have mushrooms, Sinularia, Kenya tree, yellow star polyps, green star polyps, Zoanthids and a large pipe organ. <Uh... this mix will "do it"> All of the corals are flourishing and the polyps and Zoanthids are spreading. All water readings are ideal and temperature is maintained between 79-80 degrees. Water changes done weekly. 0 phosphates. 0 nitrates and no ammonia. I add calcium daily as per instructions and Iodine weekly. Strontium as recommended. Essential elements every two weeks. PH stays consistent at 8.2. I check night time readings also. Now my dilemma. Every time I add Xenia to the tank it does fantastic for the first couple weeks pulsing away. Then it just seems to vanish by stalk overnight. There are no signs of anything getting to it and no debris or melting taking place. <Not uncommon given the circumstances of so much disparate Cnidarian life...> Water flow is good not too strong and the Xenia seems fine with it. I also have 6 fish in the tank. Two clowns, coral beauty, yellow tang, blue hippo tang and a blue damsel. We will relocate the blue hippo tang when he gets bigger. He is just a baby now. Reading the forums I can't seem to find how a Xenia would just vanish within a few hours overnight when all readings are good and does not seem to be any culprits in the tank that are damaging it?  These are fairly large stalks that are attached that vanish without any debris being left in the tank in the morning. Would appreciate any help you can give me. <Mmm, please read here: http://wetwebmedia.com/cnidcompfaqs.htm and the linked files above... It may well be that the Xeniid colonies you're getting are impugned to begin with... placing them in with established "polyps", Zoanthids... is likely too much for them to compete chemically... You might have better success quarantining, gradually exposing such to your system through gradual water changes from this garden-mixed system... Bob Fenner>

Phyllodesmium Munched Xenia? - 06/18/05 Greetings. <<Hello>> I have a 30 gallon saltwater tank with 10 gallon sump.  A protein skimmer (Excalibur) resides in the sump along with the heater.  I have about 30 lbs of Tonga live rock, with two cleaner shrimps, 5 hermit crabs, a toadstool leather coral, a green star polyp colony, one (individual) green Ricordea mushroom polyp and (most recent addition) a "Pom Pom" xenia colony.  The aquarium is about 2 months old.  Water parameters are:  Temp=78-80, ammonia/nitrite=0, nitrate<10, dKH=12, ph=8.0.  Lighting is by Coralife power compacts (96 watt 10K daylight and 96 watt actinic). <<OK>> My primary question is about the Xenia.  It was a beautiful specimen when purchased one week ago at the LFS.  Two days ago it started to "shrivel" and exhibit a small amount of "slime".  This condition worsened and this morning, before daylight, I observed it with a flashlight.  I saw what appeared to be a portion of the colony moving down the live rock below the main colony!  When I realized it must be a Nudibranch, I removed it. <<Good move.>> It excreted a clear, gelatinous substance when it realized it was detected.  I did a search on the internet and found something called a "Phyllodesmium", a Xenia eating Nudibranch, which matched the appearance.  The Xenias shriveled to less than 1/2 its original volume, but most of it is still pulsing.  What can I do, if anything, to save this beautiful creature? <<With the removal of the Nudibranch (though do check for more), tis likely the Xenia will recover...though a dose of iodine (follow instructions carefully) may help.>> In the case of its tank mates (other than the Nudibranch!), the LFS was aware of everything in the tank and I basically have followed their recommendations when selecting from among creatures that appeal to me, since they seemed fairly respectable.  I now know, after researching your site, that the ph should be > 8.3 for Xenia. <<Yes...and as stable as possible.>> How quickly should I increase the ph from the current 8.0? <<Over the course of a couple days will be fine.>> A secondary question concerns the coloration of the green star polyp colony and Ricordea.  Both have turned a lighter, more yellow-green since being in my tank.  The Ricordea is near the substrate, while the green star polyp is near the top of the tank.  Do you have any suggestions, or is this normal? <<You have them placed as I would suggest.  Coral coloration is as much a function of feeding as environment.  If you are providing good water flow (minimum 10x tank volume.), try feeding a bit if finely minced meaty foods to the corals.  Frozen Cyclop-eeze and Sweetwater Plankton are great foods for this.>> The size of the Ricordea is the same or slightly larger than when purchased, although the green star polyps don't seem to extend quite as far as they first did (perhaps due to crabs crawling on them?) <<More likely inadequate water flow.>> With great appreciation and respect, Lan Carter <<Warm Regards, Eric R.>>

Xenia predator Hello, <Hi there> Thank you for your site and help - I researched the FAQ's and noticed several references to my question, but no specifics except one post regarding a possible Nudibranch. I purchased a pulsating Xenia species approx. 4 months ago and fragged it immediately (it was ready). <Mmm, best generally to let cnidarians "rest up"...> My friend got half and his are growing like wildfire. Mine started having it's "fingers" disappear. Eventually, it shrunk up and died after the vast majority of the fingers were apparently eaten. About 2 months later, my friend fragged the 1/2 I had originally given him. We put it in my sump, in a "guppy breeder" for isolation as we tried for a couple of days to catch what we thought was the likely culprit (a very aggressive Domino Damsel... <Heeee! An oxymoron, like "military intelligence"...> ...that we wanted removed anyways). The xenia did well while down there for approx 2 weeks. (sump is lit on an offset cycle). We eventually caught the Domino, and moved the Xenia to the new tank. After a few days in the display, a few fingers were missing from the Xenia. I realize that chemical warfare is possible with some of my livestock - and I have dealt with that. It seems clear to me I have a predator eating the Xenia. Can you examine this list of livestock and offer at least a few maybes of who might be the hungry party? (using common names - sorry) Tank: 55g w/29g sump/refugium Yellow tang Ocellaris (false percula) clown Yellow Pseudochromis Mandarin goby approx 15 hermit crabs: blue legged, scarlet, Mexican red legged approx 25 snails: Turbos, Ceriths, Astreas, Nassarius (2), margaritas (2) Sand sifting star I also have various: mushrooms, Ricordeas, feather dusters, Zoanthids, a flower anemone (very happily ensconced by himself), and tons of live rock (unfortunately, my crocea died while I was on vacation and took out my finger leather and yellow stars with it).  Are any of my inhabitants likely to be the predator? Or would you think that it's perhaps a hidden Nudibranch or something? <Possibly> Also - on a side note - how far physically should the mushrooms and Xenia be separated (any distance required for the zoos?). <A hands-width or more> Thank you for your help. Sincerely, Mark <Of the organisms you list, perhaps some of the Hermit Crabs are to blame here... close examination, during the night as well as day, should prove if there is a predator here. Bob Fenner>

Phyllodesmium ate xenia Hello. I tried to send an e-mail yesterday by going to your website, but perhaps it did not make it through. I have a pom pom xenia, which was really a beautiful creature when purchased a week ago. Three days ago I noticed it "shriveling up". I inspected it during the night and found what appeared to be part of the colony moving down the rock away from the rest! It turned out to be a Phyllodesmium that had been eating the xenia.  <Collected and shipped with it> I removed the phyllo., which secreted a gluey, clear coating as I removed it from its hiding place. Inspecting the xenia afterwards, I could see that the damaged areas were whiter than the rest. I trimmed what I could of the damage away from the rest of the colony. Is there anything else I can do to help save this beautiful creature? <Mmm, not much that I know... perhaps a full-dose of iodine/ide will help. Will ask Anthony Calfo, an old culturist of Xeniids, for his input here> The remaining colonies are still pulsing but are also shriveled, although not discolored. Tank details follow: 30 gallon with 10 gallon sump, Excalibur protein skimmer, Coralife 192 watt power compact lights (half 10K daylight, half actinic), ammonia/nitrite=0, nitrate<10, dKH about 12-13, ph 8.0, salinity 1.024. The tank has been running about 2 months. I am slowly raising the ph using SeaChem's marine buffer 8.3 (supposedly reaches 8.3 and holds there). I am adding, daily, about 1/3 the amount of the buffer that the bottle recommends (just trying to be cautious).  Tank inhabitants are: 2 cleaner shrimps, toadstool leather, green button polyp colony, 1 Ricordea mushroom polyp, 30 lbs Tonga live rock. Any suggestions would be appreciated. Thanks, Lan <Keep your eyes open for other Nudibranch predators... Bob Fenner>

Re: White Crab Found in Xenia 5/7/05 Anthony, Thank you for the quick response.  Regarding my intent to forward a picture of the crab, let me just say that the little guy is really, really hard to spot, and when you do see it, it is for just an instant, so I was unable to get the photo.  I stared into the Xenia colony last night for about a half hour, and I did see the crab again, but sightings were very brief.  I even lifted the coral by its base rock at one point, because I knew the crab's exact location, but I could not find the little bugger once I got the coral up to the glass.  Once again I observed the same kind of behavior.  The crab raked in polyps with the inside of his claw by making a wide sweeping motion (just like you or I would do with out forearm), pulling them into his mouth area.  The individual polyps appear to respond by closing, but re-open a couple of minutes later and resume normal behavior.  Again, I could not detect any damage from the activity that I observed, and it seems amazing to me that the Xenia colony doesn't respond in whole to the crab's activities.  Any time that I move the colony, or even blow a direct stream of water from my turkey baster by accident, the whole colony reacts. <There are many complex relationships on the reef... some commensal, some matters of tolerance, etc> I can add that I am certain that this crab is completely white, and its carapace is almost translucent.  I will keep watching, and will update the crew if there is any progress in determining if my crab is a friend or foe. Regards, Lou <Ah, good... best of luck! Anthony>

Xenia stung by Frogspawn 3/14/05 Hi there! Thanks for the great help you provided me so far! I only have two simple questions. 1- Is there anything I can do to save a pulsing Xenia which was stung by a Frogspawn??? (Only one branch was stung) <strong water flow is key> 2- I'd like to know if the Coralife Aqualight Power Center is a good timer. (I'd really like to know. It's the only timer of this kind available around here and it's 75 $ CAN, so I don't want to get something that wouldn't do...) Thanks a lot!!! Ivan <I don't have personal use with the timer or know of anyone close that has. Better for you, do check the big message board "Reef Central" for a consensus on customer satisfaction. Anthony>

Xenia eating snail?  Or snail eating xenia? First off 40 gallon Temp: 78 pH: 8.5 KH: 8dKH Gravity: 1.024 Ammonia: 0 mg/L Nitrite: 0 mg/L Nitrate 5mg/L Phosphate: 0.25 mg/L Cu: 0 mg/L Ca: 400 mg/L My tank is almost 6 months old (Day 186) Thanks for the calcium help I have effectively reached 400 mg/L CA. I have a question about xenia. I have several Xenia pulsing away, I have had them for about 4 months. A couple of days ago I noticed one of the xenia kind of wilting and looking constricted as it sometimes does. Wondering I reached in to examine, on the other side of the small piece of LR in noticed a snail shell, completely covered in coralline algae (White flesh) that the xenia had attached to holding it fast. I did not purchase this snail and the xenia has been wilted on and off since I got it. I twisted the snail free and placed it a foot away from the xenia. A day past and I noticed that the wilted xenia was recovering but another stalk was withering. Looking I found that same snail right beside the withering stalk. My question is, "Are there snails that eat or attack xenia?"  < Not that I knew of. But hey, maybe you found one. In this case I'd put the snail in a trap or remove it entirely and see what happens. >  The snail's flesh is white, the shell is covered in coralline so I can't tell what it is naturally, any help is appreciated.  < Well I think it would be fun to test this out. Keep the snail in separated from the Xenia for a few weeks, then put him back by the Xenia. See what happens. But this is really strange to me, as I've never heard of this happening. >  Thank you, Troy  < Blundell >
Xenia eating snail continued Did as you said, I separated the snail for a day then released him into the tank. Within 4 hours it was right back on top with the xenia, and the xenia was withering. This is strange, I guess I will have to abandon the snail.  < Yep, I guess so. Crazy but I too would remove him. >  But I would like to positively id this little xenia stalker! Any ideas? < Nope, may want to continue searching. > Troy < Blundell > 

Microcrustaceans eating Xenia? Hello Again, <Hey, Mike G here.> I'm Baaaack! (Said With the "spooky" Voice) Hope the crew is doing okay. Bob, Anthony, Marina, How are you? I'm good minus the disappearing Xenia, and a couple of critters that might be eating them. Since you guys are the experts, I'll let you tell me. <I'll do my best to help you out> Man, I am going for stupid king 2005. Over the past two three weeks, my xenia started to disappear overnight (in the QT). I did some watching, the big ones disappeared, little ones started to grow, and then all gone. <FWIW, It is somewhat common for Xenia corals to "melt" when in unfavorable conditions or after drastic changes in water parameters. From the descriptions you offer, this is what I am led to believe has occurred. Check the below link for more information on Xenia and Xenia "melting" (Note topic "Xenia Health about 3/4 down the page: http://www.wetwebmedia.com/xeniidfaqs3.htm > Have one cluster left, moved into its own isolation tank after shaking off these guys. Pic1 is both of the critters I found. Pic2 and Pic3 are of the bigger one- easily ? inch in length. Is that what is eating the xenias? Bunch of the buggers in the tank! Huge! Then the top guy in Pic1 and Pic4 (Color is false image for better shape ID) are the 3/16 inch guys. Any ID help would be greatly appreciated. <I am happy to inform you that you have absolutely nothing to worry about, at least from the creatures of which you have attached pictures. Pictures two and three are of Amphipods, marine crustaceans of the genus Gammarus. Picture 4 is of a Mysid Shrimp, genus Mysis. Picture 1 is of both a Mysid Shrimp and an Amphipod. Both Microcrustaceans are welcome and benign inhabitants of nearly every marine aquarium. Check these two links for more information on Amphipods and Mysid Shrimp: http://www.wetwebmedia.com/amphipodfaqs.htm http://www.wetwebmedia.com/mysidfaqs.htm Wonderful photographs, by the way.> Thanks in Advance as always, Dan <Glad I could be of assistance. Hope your Xenia problem clears up.> P.S. I can't wait until Bob's Book Arrives - Lot's of answers I bet! He He. <<And many more questions. RMF>>

Xenia not pulsing, and hermits eating a leather? Thanks for replying.... Well, after a few 5g water changes both leathers are open, even though one of them got two laser like incisions (I think there is weird shell-less snail) - some sort of Nudibranch that I saw 2 nights ago that might be the culprit. I also see some of my blue hermit crabs climbing on top of them and harassing them at night. Could it be that the hermits are eating my leather now? << Doubtful.  They may be eating the dead tissue on them, or accumulating detritus, but I doubt they are eating the coral. >> My alkalinity is still 160mg/L down from 190mg/L so I stopped adding anything - I assume Kalkwasser is out of question too? My Xenia is still not pulsing though - some of the tentacles retract - like a closing feast but they don't pulse like before. My pH is at 8.2 - 8.3.  I have been adding only the recommended dose of iodine, but it still won't pulse. << Don't add any more Iodine, unless you test for it and know what levels you have. >>  Is it normal for Xenia tentacles/arms to extend to 7-8 inches length? I've seen some in various LFS but none were extending that much like mine. I have them under medium current. << For Xenia to pulse I think you need 1) lots of light, 2) more light, 3) proper alkalinity, 4) low nutrient levels. >> Thanks. Dimitris << When in doubt, just give it time. Blundell >>

Mystery crab I had a nice xenia piece growing rather well in my tank and overnight I lost about 2/3 of the coral. I did an exhaustive search and never found a thing other than a stowaway crab that I never purchased.  I did some research and found out that it is most likely a Eriphia smithi crab, aka: red eyed reef crab, aka: liar crab. it is about the same size as my emerald crab, but reddish brown with red eyes. I've heard from web users that it is a carnivore and that it has probably been the cause of my missing snail phenomenon as well as my disappearing xenia trick. <May well be> unfortunately no one knows anything about the animal other than "he's bad" and its "carnivorous" all I can find on the web is in Russian.  and despite all the vodka I drink, I still cannot decipher the Russian. <Heee! Maybe try Babelfish (the program, not a drink)> if you have any info or links for me to read id very much appreciate the help.  I removed the crab and placed him in my fuge just to be safe. <Good move> but id like to know before I buy any more livestock if that was probably the cause of my problem.  the only thing else in my tank is:  green Brittlestar, percula clown, blue legged hermits, yellow tang, and assorted snails. <None of these likely implicated> any help would be appreciated. Edwin <I also know very little concerning this crab... or speak/read Russian... I do hope that its removal solves your mystery. In the meanwhile, do keep your eyes open, maybe take a peek during the night with a small flashlight to see if there's something else mallurking. Bob Fenner>

Xenia troubles Mike,  <Anthony is the ultimate xenia guru in the group, but I thought I would chime is since this is fairly common.> Having a bit of a weird problem here.  Earlier today my two xenias (actually turning into 4 xenias) looked fine, pulsing like mad, etc.  I did a 1 gallon water change (I do this every two days, tank size is 40 gallons) with a bucket of water premixed (been using this water all week).  About an hour later, the xenia started closing. <I am assuming no change in salt brand, etc. and that you have checked alkalinity.  Also consider if you have changed lots of salt within the same brand (Instant Ocean doesn't seem to be the same super consistent product it used to be.)>  That didn't bother me, as it sometimes closes when something annoys it (hermit crab, etc) but then it started "shriveling" (turning a dark purple and shrinking MUCH smaller than I've seen it before).  However, 10 inches away is another xenia doing just fine.  As I write this I'm pretty sure one of my xenia bunches is just about dead, and the other is fine.  Any ideas?  All other corals fine, too...don't see anything close enough to sting it.  Don't know what's wrong :( <Sometimes this seems to be cyclical/seasonal, so any noteworthy event could be co-incidence.  I have a variety of "giant xenia" that melts down at the drop of a hat (when others continue to thrive).  It drops polyps all over the tank, and in a few weeks tiny colonies are popping up all over the tank.  Overcrowding, changes in temperature, changes in water chemistry (especially alkalinity) have all been suspected as causes or triggers.  It is always fishy (no pun intended) when some declines while others thrive.  I hate to leave things without explanation, but this type of event is fact of life with xenia, and it is xenia after all.... in six months (or less) it will be back to being a pest.  If you want to try and run down the cause, do test your newly mixed water and compare the pH and alkalinity to the tank.  If you have an ORP meter, do also compare the RedOx of the new water vs. the tank and the tank pre and post change.  Do keep an eye on it... often it will recover, sometimes growing new colonies from the tiniest undetectable little scraps of tissue left on the rocks.  Hmmmm... looking back at this reply, it is a lot of non-committal fluff.  I guess the bottom line is that nobody knows.  I am a pretty serious xenia junky and read a lot about xenia on the boards, chat a lot about xenia with other addicts, etc. and have never heard a reliable, reasonable explanation. Regards, Adam>
Re: Xenia troubles Actually I figured it out (stupid me).  There is an Aiptasia anemone hiding in a rock behind the xenia, and it must have stung it.  The xenia is looking slightly better, so hopefully it will live.  I'll have to get some Aiptasia eating Nudibranchs soon.  Thanks for the input guys.   M. Maddox<</p>

ANTHELIA DIE OFF I was hoping you might have some experience with an anthelia die off.  << I actually do.>> I have a 120 gal tank that has been running for two years.  I have not made much in the way of changes to the bioload since I set it up and stocked it over the first six months.  Over the last four months I have had a patch of anthelia just slowly wither away.  Also, I lost a lawnmower blenny that just seemed to waste away after a year of being fat and happy.  A great looking Tubipora grew like crazy, the started looking raggedy and wasted away (I think my yellow tang may have decided was tasty) and a Trachyphyllia that used to be inflated beyond anything I have seen (feeder tentacles were out 24/7) now just looks like ones I seen in the stores.   On the other hand, I've had Ritteri that is growing and thriving for well over a year (I don't feed it very often, is that bad?), a Euphyllia that has tripled its branches, xenia that is growing like weeds (any ideas on controlling it) a Pavona and two Pectinia that are growing, a Sarcophyton that I have trimmed drastically twice, and a Pocillopora that must have reproduced because there are now a dozen small colonies all over the tank.  The mixed bag of results has me worried that I am missing something.  On the other hand, some stuff is going gangbusters and I reluctant to change my routine, which isn't much except reef builder for alkalinity and calcium.  None of the shops has much in the way of advice.  Am I heading for disaster? << I don't believe so.>> Are there other additives I should be using?  << I don't believe Anthelia needs additives.>> Should I try another lawnmower (my wife's favorite fish).  Can you tell my how to I go back in time and decide pass on the small colony of pulsing xenia?  << Ah yes, the million dollar question.>> << Okay here is the first thing I would suspect.  Do you have any Peppermint Shrimp?  I didn't think they would eat Anthelia, until my peppermints ate all my Aiptasia.  Then sure enough, as my friend warned me, I saw them eating Anthelia at night.  If that isn't the case for you, my second guess it temperature.  For some reason when tanks get warm (I'll say above 80 F) I've seen cases where the Anthelia declined.  If that too isn't the case, please write back.>> << Adam Blundell>>
Re: ANTHELIA DIE OFF Adam, Thanks for the reply. I put some peppermint shrimp in when I started the tank.  I don't see them often and it's been several months since I've seen one.  The anthelia thrived for a very long time before it started to disappear.  << My anthelia did well forever, until my peppermints had eaten all my Aiptasia, and then all my yellow polyps.  Just something to keep an eye on. >> Most of the tank is fine with the exception of the anthelia, the Tubipora that suddenly crashed after doubling in size (maybe eaten by yellow tang?) << Very very doubtful that a yellow tang ate it. More likely some invert. >>a Lobophyton that looks good, just not nearly as good as it did a couple months ago.  Everything has been very consistent but a little low for the past eight months (I test weekly).  Alkalinity has ranged from 2.8 to 3.5, calcium between 300 and 200, and pH steadily fluctuates between 7.9 in the morning to 8.3 at lights out (meter calibrated every couple months).  My temp is consistently between 78 and 80 and the nitrates have never been above 10.  Like I said in my original email, my Ritteri is growing and hasn't moved an inch in four months, SPS and clams are all pretty happy, and I can's stop the pulsing xenia hordes,  so I've been reluctant to add a lot of stuff.  I just wonder if the there is something else I should be looking out for in terms of long term water condition.  << Many people like adding Iodine for their anthelia.  Are you dosing Iodine?  Be careful if you do, because it is easy to overdose. >> On another note, I am on the verge of committing to plumping through my floor and creating a first class sump system in my basement next to my RODI.  I am not the best at routine tasks except feeding and replacing top off water (hence my low numbers).  I am very good with weekly testing and scheduled things like replacing bulbs, prefilters, etc.  The purpose of going in to the basement is to give me more room to facilitate easy skimmer cleaning, water changes, top off, etc.  I am looking for a little advice on what is the most dependable, least crashable, set up.  << Yes I do have some advice.  First, you will need a very large pump to pump that far up to your tank.  And your plumbing lines will contain a lot of water, so to avoid a flood you need a lot of extra volume space in your sump.  For a lesser chance of crashes, and the best pH stability, I highly recommend a reverse daylight photosynthesis type of refugium.  Keep it half way filled with different algae species. >> I have pretty much decided on a chiller for peace of mind (if the A/C goes in my house it's all over, or at least no lights until it's fixed). I am looking for the best way to dependably maintain pH, alk, calc, trace elements without having to mess with stuff daily.  Ideally, I'd test the tank weekly (except for pH and temp which I have displayed near the tank), go down every night to check the sumps and equipment, but not have things running that, if they get stuck will crash my tank.  Any advice on dosing pumps, calcium reactors, Kalk reactors, pH controllers, UV, etc.<< I don't have any specific recommendations. Just take a look at other set ups and see what is working for others, and will work for what you are hoping to accomplish. >> <<  Adam Blundell  >>

UFO on Xenia & Lobophyton 5/21/04 Last night I separated the Xenia from its base rock. It came off in 3 sections, including one that looks healthy, a tiny bit left from the branch that had previously had the most necrotic tissue, and a large double branched stalk, one of which has a weird porthole on its side with a pregnant bulge just below it. From the bottom, it looks as if one or more strands of the parasite have wormed their way up into the left, bulging side of the Xenia. http://www.culturedaquaria.com/xenia/xenia4.jpg  http://www.culturedaquaria.com/xenia/xenia5.jpg  I'm considering splitting that piece in half vertically to isolate the bulging side from the healthier side. <OK... seems like a sustainable move> Whether or not I do that, I'm unsure what to do afterwards. <the frags can be sewn to the next rock rubble with plastic sewing thread or thin fishing line, or they can be speared and impaled by a cocktail toothpick (the plastic jobs with the ornate ends that prevent an olive/coral from sliding back off)> This Xenia was in my large display tank positioned near 3 other prized Xenias which, like the one under alien attack, I'd raised from tiny frags. I have several other brightly lit tanks that contain corals but no Xenia. Do you think that would be a safe place to put them? <I cannot say, since the photos do not clearly reveal anything at all that could be parasitic. The pics simply show some necrotic areas. It could be stinging hydroids making their way up and through... could be another predator... or could simply be anomalies on a Xenia that is not being attacked at all, but rather is suffering from aggression from other corals in the tank, or low pH (below 8.3 at night)> Should I try to mount them to rocks now or wait awhile? <mount them immediately after fragging, and keep them away from other Xenia> My coral tanks have powerheads and hang-on filters, so they would be at risk of getting sucked into or up against an intake. (I've grown several Sinularia frags out of disgusting blobs that I pulled out of filters, but I doubt the Xenia would be that accommodating.) Thanks, Suzanne <beat regards, Anthony Calfo> 
UFO on Xenia & Lobophyton II 5/24/04 For awhile, I thought the mysterious roots growing at the base of my Xenia might have something to do with reproduction (though I'd never read of anything like that). Today, however, there are patches of necrotic tissue and sponge or sponge-like gunk around the base rock. <I see... agreed. Sponge-like indeed> The root-like strands appear to be coming in and out of the coral tissue. <irritating the Xenia and causing the necrosis> My impulse is to either start trying to remove the strands and sponge, or to cut off and try to salvage the healthy areas of the Xenia. What do you think? <the first at first, and the latter if necessary> http://www.culturedaquaria.com/xenia/xenia.jpg  http://www.culturedaquaria.com/xenia/xenia0.jpg  http://www.culturedaquaria.com/xenia/xenia1.jpg  http://www.culturedaquaria.com/xenia/xenia2.jpg  http://www.culturedaquaria.com/xenia/xenia3.jpg  Also, some of my Sarcophyton and Sinularia sp. corals have long strands similar to spider web silk streaming off of them. I've read of a small jellyfish relative with tentacles similar to this. Is that what I'm seeing? Will they do any harm to the corals? <looks like a Hydrozoan of some sort... some such Hydroids are extremely (!) painful for you to touch. Remove carefully!> http://www.culturedaquaria.com/xenia/lobophyton.jpg  thanks, Suzanne Hathcock <best regards, Anthony> 

2 questions... (Small reef system, Xenia) Hi there everyone, First off, I really enjoy the website and have gained much valuable insight from your responses.  <thanks kindly> Now to add my own query to the growing pile of information... I have a 25 gallon reef tank which has been up and running for about seven months now. I have a great colony of pulsing Xenia which has been rapidly spreading and dividing. Recently one of the stalks basically fell apart (shed polyps and disintegrated) over a matter of a few days. All the others look great and still appear to be growing/pulsing like mad. My setup and water quality is the following. 25 g tank with custom skimmer (some daily product) and 2x55w pc lights. 35lb live rock with 2 in bed of live sand. Ammonia 0 Nitrite 0 Nitrate 0-2 ppm pH 8.3 Alk 2.8 ml eq/l Temp 78 SG 1.027 <nothing stands out conspicuously here> I don't add anything to the tank other than RO water, and 1-2g water changes each week. Other than the Xenia, the other inhabitants of the tank are: 2 small Sarcophyton leather corals 2 Ricordea mushrooms 1 feather duster 5 Xmas tree worms 1 (spreading like mad) colony of Pachyclavularia polyps 1 True Percula Clown 4 Turbo Snails ~10 Blue Leg Hermits All the tank inhabitants have never looked better (even the rest of the Xenia). I was wondering if you had any ideas on why the one Xenia stalk would have crashed so suddenly (and why the others still look so good). <depressed pH is a common cause... is 8.3 your daytime reading? If so... test after extended darkness (first thing in the AM)... see if you are much below 8.3... quite stressful for some Xenia. Else... are there mushrooms or Starpolyps nearby? Xenia is quite passive and this colony may have succumbed to coral aggression> My second question concerns the Pachyclavularia polyps. On the corner of the rock on which they reside, there are several small holes (~1 mm diameter) from which periodically throughout the day a very small translucent tentacle whips out and nettles the stolon mat that is close to the holes.  <yep... barnacles if iridescent like fiberglass... else a worm of some sort... very cool either way.>  Since I've gotten this coral, the polyps near these holes never extend any more and even the stolon mat has receded a bit from this corner of the rock. Any idea what the heck is living in that rock that is nettling the coral? And further, how should I deal with it? The rest of the coral is doing great and spreading in other directions to other rocks. Thanks so much for your time, I look forward to reading your responses. Jeremy <best regards, Anthony>

Xenia elongata Help Please!!! Ok I have a 180 reef tank. All kinds of corals, frog spawn, bubbles (brown and white), Fox, clams, etc. Everything is doing GREAT .The problem is I can't keep Xenia. It got real small and died. Tried some more and same thing.  Water is in GREAT shape. Cal.450  KH 10, PH 8.2 every thing is good. Give the tank Iodine, DTs. It's on an ecosystem with 40watt.Uv, 440 VHO lights white and blue. (it's up top high) ANY IDEAS on why I can't keep this stuff ???? Thanks so much for your time, Chip <the strong presence of LPS corals is quite aggressive. Placement of the Xenia within 10 inches of many LPS species is a kiss of death for some Xenia (not all... some are quite durable). If the tank also is not skimmed aggressively to dilute the chemical toxins, or is water changes are modest (less than weekly)... then we may have your problem. Try keeping them in a refugium inline instead. A nice feature for the tank. best regards, Anthony>

Xenia Lost Their Zip! Hi Guys <Scott F. your guy tonight> I have Pulse Xenia and white star and some metallic green xenia all other corals bubbles, leathers and other polyps are quite happy. But the Xenia never seem to grow and the pulse stays contracted but still pulse? The green xenia looks like it may be dying off. Water quality is fine ,will additional strontium help? <I have not heard of strontium supplementation being beneficial to this species...> or am I missing something else? Thanks, Tim <Well, Tim- there are all sorts of theories as to what makes Xenia pulse. Some hobbyists swear that iodine supplementation is the key, others feel that light and current play a bigger role in this "behaviour". A valid theory is that Xenia tend to pulse at steady, higher pH. Xenia are thought to be autotrophic, meaning that they don't generally require supplemental feeding. What you need to do is to review your tank's parameters once again, checking that pH. Perhaps you are positioning your Xenia near other, more aggressive corals, and they are becoming victims of "allelopathy" (chemical "warfare")? You certainly could experiment with iodine- but do test for anything that you should add. Do pick up a copy of Anthony Calfo's "Book of Coral Propagation" for a thorough review of the care and propagation of Xeniids. Do a little research- you should be successful! Regards, Scott F.>

Coral Calamity (RECAP day 3 (HELP!! DYING xenia corals) Ok.. so my pulse corals (both colonies) literally deteriorated.. and I'm assuming that the decay from the dead corals probably caused a spike ammonia.. <Very possible, when you are dealing with a lot of decomposing matter in a tank> Strange thing,.. all the leathers in my tank are expanded, but their polyps aren't extended at all and that one colt coral just doesn't wanna open at all.. another thing about the colt (Sinularia sp.) is that it had black spots (2 or 3 of them) that almost looked like slime algae.. .. I used a turkey baster to try and spray off the spots and it didn't work so I had to use my fingers by gently rubbing the covered branches. <I wonder if this was something other than algae...Hard to say from here. May have been some decomposing mucous or other material that "stuck" to the coral> Underneath the stalk appeared emaciated and colorless.. we also proceeded in doing a 25 gallon water change in which we did 5 gallon water changes every 20 minutes in order to let the water mix as to not change the parameters of the tank too much.   <Good idea...Sometimes, environmental lapses can cause a temporary lapse of turgor (i.e.; they become "deflated"). Usually, all that is needed to "perk them up" again is a water change> On a lighter side.. my rose BTA is expanded really nicely :) <well, ya got to feel good about that, huh?> Another question I have is that with Euphylliids and bubbles.. can they be housed with members of the same family?  I have an octo bubble and a white bubble that are relatively close together, but they have never touched (but if either decided to grow then we might have a problem.. and as for the Euphyllias.. I have a torch, elegance, frogspawn, and hammer.. can any of these corals be housed next to each other?  Or will they sting and kill each other.. and if not then can 2 hammers or 2 frogspawns etc. be housed next to each other? <Well, in all of the examples that you give, these corals are quite capable of stinging each other. Euphyllias pack a real wallop, and can send out really L-O-N-G sweepers...I'd make sure that you keep them quite far (like 10 inches or more) apart in an aquarium...They really do "defend" their territories, so keep this in mind when placing them.> Thanks again, Jonathan <Good luck with your coral community, Jonathan! Regards, Scott F>

Declining Xenia 6/7/03 Hello, <cheers> A few weeks ago I purchased two small colonies of pulsing xenia (not sure what specific kind).  They were placed in different areas of the tank in a med. to high current and both were doing fine for several weeks.  Probably five days ago they began to shrink in size.  The pom-poms are still opening during daylight hours but the stalk and each individual arm keeps shrinking. I have a 55 gallon reef tank which includes: 1 Chromis (due to a bout with ick, tank had been fallow for a month. This          fish just added a week ago) 1 star polyp (doing fine) 1 metallic green brain (added at same time as xenia, it's doing fine) 1 brittle star 1 banded shrimp 50lbs live rock 15 gallon sump w/refugium Prizm protein skimmer removing dark liquid daily ammonia 0 nitrite 0 nitrate 0 (or very close to it) dKH 10 ph 8.3 260w compact fluorescent lighting temp 79 salinity 1.25 -1.26 (not as stable as it should be due to daily changes in humidity and evaporation) 5% water changes weekly <nothing stands out as a problem with water chemistry... unless that pH is a day time reading in which case your pH may actually be dropping to well below 8.3 at night (bad for Xenia)> Concerned that iodine might be the problem I began using Kent's Tech-I (used as directed) a couple of days ago but there has been no sign of improvement. <lack of iodine can be a problem, but only here if the iodine is old (over 2 months)> It has been suggested to me by LFS that my tank may be too clean. <I guarantee you that is not the case... in any aquarium!> Not enough nutrients for the xenia to absorb and that I should add more fish. Something obviously needs correcting but I'm not sure what it may be. I really don't want to lose them! <lack of quarantine or acclimation to light is more likely a factor. Aggression from a neighboring coral even more so (Starpolyps or other coral within 10"? Shedding chemicals/allelopathy)> Thanks so much for your help, Bryan <best regards, Anthony>

Anemone identity please 6/22/03 Anemonia cf. majano? Hello. First I want to thank everyone for the website, it's information, and the crew for their excellent knowledge. <Thanks kindly... our pleasure to do so> I have done my share of research in the books, websites, and FAQs, but I still don't know what this creature is. Can you please help me identify it and give me some instructions on what to do with it? It appeared today (four days after purchase), on a small branch with Xenia (reason for purchase). It looks somewhat different now (pictures) then when I first discovered it. It was open all the way at first, longish tentacles with small bulbs at the end. The color is brownish/pinkish. When open, you can see the oral disc and mouth (the mouth is of white color). It is a bit closed in the pictures. I have a large bubble tip anemone in the tank (purposely purchased).  Could you please identify this creature for me, and tell me if it will damage my Xenia as it grows, and should I evict it from my tank, and how? I try to remove it, but it is quite stuck to the branch, and because of its near location to the Xenia, I'm afraid that I might damage the Xenia in my attempt to remove the creature.  I would approximate the creatures size at about .5" in diameter, fully open. Thank you in advance for your time and help.  Min Windhorst <Do look at a range of pictures of the species Anemonia majano and see if you don't they might be one in the same. Some variability of color, but a common nuisance with corals like this Xenia imported from Indonesia. Best regards, Anthony>

Red crab is eating my xenia. Hi Bob, <Anthony Calfo in your service> I recently set up a 70 gal reef take to replace my existing 30 gal. I purchased about 50 lbs. of Fiji live rock from a local retailer which of course came with many pleasant surprises.  <yes...many such joys with fresh live rock> The tank has been running for about 5 months now. About 2 months ago I placed some green star polyps that are doing fantastic. Based on the success of the star polyps I figured I could start transplanting the rest of my corals into the new tank. I started with a small xenia and a Sarcophyton. This morning when I looked the xenia was gone and the Sarcophyton had a bite taken out of it. I looked with a flash light in the holes in the live rock and saw a red crab munching on the xenia.  <Arghhh> The crab is roughly the size and shape of an emerald crab but it' s bright red. Any idea what kind of crab this is and is it a notorious problem in reef systems.  <actually, most crabs including emerald crabs can be predatory in reefs. Most all are opportunistic predators. So... if hungry enough <G>> Other suspects are a 6 line and a peppermint shrimp. Any advice is appreciated. <the crab is by far the likely candidate. Do remove and resist even most "safe" crabs if you want great diversity of microorganisms in live rock and sand> Thanks John Allen <best regards, Anthony>

The one-armed Xeniid did it! <Lorenzo again, 'playing Bob'>
Question:
Just today I noticed that on my of my main stalks of pumping xenia one limb has turned a whitish-yellow and has shriveled to the base of the limb. Yet the rest of the stalk is fine, what could be wrong with it? I really don't want to lose it because it has been doing great and growing fine. Thanks for you time. <Probably somebody else 'took a taste'. Got any butterflies or angels? Xeniids of the pulsing sort are mostly hard-to-kill, unless your tank conditions are just horrible... -Lorenzo>

Pom Pom Xenia Hi Bob, I don't know if you remember, but you sent me few replies about my pom pom xenia and what I thought was a disintegration problem. I increased calc from 485 to about 540 and my PH from 8.3 to 8.4. I also increased my Iodine by about 50% and started adding it on a daily basis instead of once a week. All of this seemed to have helped as the xenia perked up a little and the "dissolved" tissue seemed to have healed up. But he was still not as open and nice looking as he was the first week, so I kept looking for something else. Well last night I found the it! About 3 hours after the lights went off I was looking at the xenia and noticed a piece that I thought was separating off, but it was a Nudibranch. It was actively eating the tissue at the base of the Xenia. It's body blended in perfectly with the xenia and the filter/hairs I forgot what they are called) on its back mimics xenia polyps very well! With its camouflage and the fact that it was living on/in the rock the xenia was attached to it almost seems like this thing is specialized to feed on xenia. I tried taking a picture of it but I don't have a dig camera and my connectix camera doesn't work for up close stuff. I have not heard of a Nudibranch attaching xenia or found any info on it. The bite marks which were quit raw last night healed up at least 50% by this morning and look smooth like the tissue has dissolved away instead of having been chewed on, so I reasonably sure that this has been my problem all along. You mentioned that you had some friend who propagate xenia commercially - do they have a web site or some way to order from them?- have they seen this before? Is it likely that there are more or that this one laid eggs? >> Have heard of Nudibranchs on pulsing corals, and do agree that this one is very likely a specialized feeder. Pretty curious as so much of the Xeniids are (appropriately) cultured at local levels around the planet. Not much chance for wild-predator introduction. May have laid eggs... you'll just have to keep your eyes open. A few propagationist friends do have sites, best for you to search them (and who knows who else) out via your search engines. Bob Fenner