Hydroids, control  – 6/4/08
Hello again Crew,
<Hello>
After a hair algae explosion, I now have an explosion of hydroids (see pic below).
<No picture attached…>
They are covering all of the surfaces inside the aquarium and sump. I don't mind them because they are simply demonstrating the "fertility" of my aquarium.
<Rather the polluted state. Plague levels of a single organism are never signs of a healthy ecosystem; biodiversity is the key.>
They're very small, so should I be worried about them stinging?
<Yes. Many hydroids pack a wallop.>
Will my snails and/or hermit crabs eat them and/or the hair algae?
<No. Careful control of nutrient, overfeeding, etc. will thin the herd.>
Well, I have to catch the bus.
Thanks in Advance,
<Welcome>
Random Aquarist
<Specific Benjamin>
 

Help with Hydroid myrionema.  - 04/14/08 Hello Again. I believer you are correct on what i have (hydroid myrionema). We have a hard time getting rid of it. <Yes... can be a real bugger> I have searched on line for remedies. With my tank being 200 gal. reef safe with the following (blue tang/unicorn tang/clown tang/2 yellow tangs/cleaner wrasse/Lunare wrasse/blue damsel/Banggai cardinal/pajama cardinal/blood red Hawkfish and a mated pair of green mandarin gobies) a clean up crew and we have feather dusters/tube anemones/polyps/frogspawn/leather corral and mushrooms. We do water changes for nitrate levels, and have decided to move to the Zeo system. However i wanted to know what this Panacur is all about. On line people have used it to get rid of the hydroids, but does it work, and will it help me. Thanks MC <Mmmm, what are the active ingredients in this product? Bob Fenner. Re: Help with Hydroid myrionema.  4/16/08 April 15, 2008 Hi again. I'm sorry the product people are using to get rid of Hydroid Myrionema is Panacur, the main active ingredients is Fenbendazole. <Ahh!> I wanted to know if i could use it? <Mmm, well... it may well kill off a good deal of the "wormy" life in the system... is an anthelmintic... and most all marine systems, natural and aquarium have substantial worm faunas... So, at the least I'd have a good deal of pre-made water ready, be aware that changes may need to be made... successively, along with the use of chemical filtrants, change of mechanical media, cleaning of skimmer/s...> But I wanted to make sure i don't kill off my tank. <You are wise here> What do you suggest? I'm at my wits end with this hydroid, (working on it for over 9 months) and if it weren't for my mated pair of green mandarin gobies, which are doing very well, i would kill of my rock and start over. <Mmm... I would try some biological controls first myself... or move all the "desired" livestock elsewhere for a few weeks, while using the "de-wormer". BobF>

Hydroid jellyfish -01/29/2008
Hi,
I have a lot of these in my tank glass. I try to use the magnet cleaner to scrape these off, but their number never seems to reduce. Is there a
way to remove these from the tank? Thanks in advance.
<Patience and time work best. These things typically have population boom and bust cycles. You can help things along by scraping them off with a razor blade (if a glass tank), and suck them up with a water change.>
Regards,
Kash
<Best,
Sara M.>
 

Hydro ID and help – 1/04/08 Hi guys, Thanks for maintaining such a wonderful site. I have been visiting this site for over 4 years now and have always found to be a great source of information. I need a little help though, and would appreciate it if you guys could give me a hand. <Will gladly render my input> I'm looking for a positive ID on this little critter (see attached). After exhausting all resources here at WWM on Hydrozoans, I went looking for better classifications of these guys and I found a great site for identification: http://www.ville-ge.ch/mhng/hydrozoa/hydrozoa-directory.htm. I think I've come to the conclusion that this is probably Class Hydrozoa, Order leptomedusae Family Malagazziidae <Appears so to me as well> I only see them in the Hydroid colony stage. Hopefully I'll never see the medusa stage ;) <Is, will be there in time... likely being removed by your mechanical filtration> Anyhow, looking through the articles at WWM I'm trying to find out how to really get rid of these guys. Everything I've seen at WWM says starve them out and remove the nutrient rich environment. My question then becomes "what nutrients?" <In boldest statement of what can be easily measured, soluble nitrate, phosphate...> What do these guys depend on to grow? <Mmm... some chemical base, micro-fauna... a dearth of predators, competitors> Although, the appearance of these things seem to correlate with my use of Koralle-VM from Brightwell Aquatics. I have since changed to Coral-Vital from Marc Weiss Companies, Inc to see if it will have a different effect. <I would drop this Weiss product... and most all of its ilk> They also seem to be accompanied by this brown looking mush on the live rock. I have an 11 Gal Aqua-via tank, with an Aqua C remora Protein skimmer with Maxi Jet 1200, 25lbs LR and a 3in sand bed. I only have a couple of zoo's and a single clown fish. Not really much of a bio-load here. The Aqua C should be more than enough of a protein skimmer for this tank/load. Any ideas on how to starve these guys out? Any specifics would be greatly appreciated. Thanks, Jas <Mmm... well... I might try a small shrimp (or two)... perhaps Lysmata wurdemanni... in the hopes of them eating up the hydroids. Bob Fenner>

Stinging Hydroids HELP w/ pred. control   - 4/7/07
Once again I'm back for expert advice..
<Okay>
I've done some extensive reading on stinging hydroids on your site.
In fact, I've found my pests picture here http://www.wetwebmedia.com/hyzoanidfaq.htm
Article: Bad boyz- hydroids 12/30/03
You've mentioned in other articles that these have few reef safe predators.
<Yes... though these are often quite "species specific">
What would the predators be of the "tube like coiled at the base" string hydroids ?  
Nudibranch is one critter that keeps coming up.
<Some species... definitely not many/all>
I have sooo many at this point, scraping them off would take forever.
Thanks,
Chris
<Well... the path may be long here... and not one I would take... experimenting blindly... If you want to go this predator route, FIRST (dang, that's bright), you should determine as closely as practical, which species of Hydroid you have... will require the use of reference works, a microscope likely... I'd try writing some folks on the Net who work in the field of taxonomy, biology of the Hydrozoans for suggestions here... Bob Fenner>

Re: Starfish and Hydroids?  Blue Linckia (Linckia laevigata) Better Left in the Sea.  2/9/07
<Hello again Travis!>
Thanks for the great info, Mich!  I'll avoid the blue Linckia star!
<Very good!>
Follow-up question:
<Sure.>
Would any/all starfish be damaged/irritated by crawling over rocks covered in hydroids?
<Yes, it is possible.>
i.e. If my rocks are mostly covered in hydroids, do I have to rid my tank of them before I could add any (non-sand-dwelling) starfish?
<Mmm, no, but again not for the reasons you state.  I am hesitant to recommend any starfish that are of the "rock scrubbing" type which I believe you are considering.  Most just don't do well.  Serpent and brittle stars should be fine.  I wouldn't recommend the sand sifting star either, as it will take out much of the beneficial fauna in the sand bed and then starve.  Hope that helps!  -Mich>   
Travis.

Hydroid control? 1/27/07
Hello...this is Stephanie.
<Hi, Stephanie! GrahamT here.>
I am new to nano reefing.
<Welcome to the world of micro.>
I have been reading about hydroid problems with zooanthids, unfortunately, we were too late in saving it. It smelled pretty bad and didn't look to good.
<Unfortunate... sorry for that.>
But, my question....could this problem have spread to our hairy mushroom?
<If you mean, can it spread nearby and sting, yep. If you mean can it infest the mushroom, then I have to say I'm not familiar with them moving about. I am somewhat inexperienced in the hydroid "field" but in my research ( http://www.wetwebmedia.com/hydrozoans.htm and all links...)I learned that they need somewhat higher concentrations of nutrient to thrive. Also, they are usually "fixed" to the rock.>
It looks good but has a few areas that look similar to the zoanthid.
<Am I missing a past email? What did the Zoo look like?>
  Please help.....
<Trying...
-GrahamT>

Hydroid control? <follow-up> 1/28/07
Thank you for the quick response, Graham T.
<Welcome, though not immensely helpful, I suppose.>
I made an error when I put Zoanthid, I should have put hydroid.
The patch on the mushroom, or I should say on the rock is grayish and looks velvety. The other spot on the Zoo was actually "moving" little things you could barely see. So, somewhat different but I am worried I will miss this and then it will be too late.
<I want to be sure not to mis-diagnose. Is there a chance you could send a pic (under 400K) so I can get a look at the critter?>
OR.....could this be fungus? The rest of my life rock doesn't show any areas like this one.
Overreacting or playing it safe?
<Always playing it safe...
-GrahamT.>
Thanks
Steph

Hydroids infesting my Zoanthids?
Dear Crew,
<Russell>
Here's a new one for me...maybe you also?
<Could be>
Over the holidays my Zoa's (four frags, about six months old and previously healthy) closed up and became infested with little critters. My Ca and dKH dipped mildly when I was out of town for three days, but otherwise the tank was stable.. (need to get a calcium reactor, my 2-part dosing pump is temperamental).
These parasite-like things attach to the closed polyps and are too small to photograph accurately. They look like a small (1-3mm) hydroid-ish creatures, having a clear stalk with small white-brown tentacles. They start like white little dots and grow pretty fast, spreading to all colonies and show tiny tentacles. I had hydroids on my tank walls last year, but they went away after a month or so.
<Typical>
Last week I removed the frags (some had already grown on to surrounding rocks) and did a 15 minute dip in a gallon of tank water with a salinity of 1.015 and over a tablespoon of Lugol's... at the same time blasting the frags with a turkey baster. This seemed to do the trick upon reintroduction... most polyps re-opening and looking good.
<Good>
Then, over the last two days, the little critters came back so last night I re-dipped the frags- same as above except for 30 minutes AND I followed this with a flash RO/DI water dip. I also pruned and discarded the remaining small amount of new growth- polyps left behind on my LR (figuring these small stragglers were still infected and causing the problem).
<Mmm... much more likely to be residual animals in your system... really need to dip, move the Zoanthids to another setting>
This morning the frags, for the most part, are open with no obvious critters.
Could these be hydroids??
<Oh yes>
I've searched this site (and others) and am confident it is not "reef pox" which is more pustular, ulcerative in nature. If these apparent parasites come back, any other ideas????
<Mmm, plenty>
Interestingly, I also recently picked three Nudibranchs off the Zoa frags. I don't think the infestation is from Nudi eggs. Also, they are not Zoa spiders.
Thanks, Russell in KY
<Hopefully gone for good this time. Bob Fenner>

- Choerodon fasciata & little stinging hydroids -
Dear WWM Crew, I have a 240 Gallon with approximately 70 pounds live rock.   On 11-22-02 I added a Harlequin Tuskfish "Tigger" that had been quarantined for two weeks with no signs of parasites or other.  I have noticed tiny Hydroid jellyfish (polyps) on the glass (dots with legs). At first I thought this was a really cool find from the live rock, but a few days ago I noticed spots on the pectoral and tail fin of Tigger, on closer inspection these spots really appear to be the Hydroid polyps.  Can these polyps attack the fish and be a parasite of sorts? <Not attack, per se... but if the fish bumps up against them... sure. But I will just add, as I also have a harlequin tusk, that spots on the tail are not uncommon. They come and go pretty regularly.> Tigger's color is bright and is eating well, and does not appear to be scratching or have any abnormal breathing. <Good deal.> There are not any other fish in the tank.  I am concerned about Tigger's health, the health of the tank, and about adding any new fish until I am sure these hydroid polyps are not going to cause a problem. <No fun... you may want to consider creating a scraper/siphon combination that would allow you to scape off a hydroid and immediately suck it out of the tank. You definitely don't want these floating around the tank. You may need to take more drastic action, I'm sorry to say. Hydroids are a pain - quite literally.> Your help is greatly appreciated!!   
Thank You.  Jen Marshall
<Cheers, J -- >

Removing finger-like hydroids
Stinging hydroids have few natural predators that we can regard as reef-safe. If you have corals in the tank, it may be difficult to avoid manual extraction. In the meantime, you could try a stiff bristled toothbrush tied to the end of a siphon tube so that you could siphon slowly and scrub at the same time. We need to avoid fragmenting and spreading them. Bets regards, Anthony>

- Hydroid Problems -
Hello. <Hello, JasonC here.> How are you today? <Well, thanks for asking.> I have a 55gal. tank set-up for a little over a year with a sebae, two clown perculas, Zoanthid, a hairy mushroom, Sarcophyton, electric star polyps, various sponges (blue, red candy cane, and yellow), a green hard coral, 3 crabs, 8 snails, and a velvet damsel. I have PC lighting 6-65watts, new bulbs every six months whether they need it or not, CPR Bak Pak II protein skimmer and a calcium reactor. All have lived happy and healthy in this environment. About three months ago a friend bought me a sun coral. I quarantined it for three weeks to ensure it was eating correctly and content. I added the coral and three to four weeks later I noticed a lot of "feathers" in the tank on all of the live rock. I am positive it has been identified on your site... hydroids. <Egads.> I tried the siphoning technique but the base is so far into the crevices it reproduced 10 fold. My question is how bad can these things affect my tank? <Well... for their size, they are pretty potent stingers.> I am afraid they are affecting my Sebae. <Quite possible.> He is sitting up but he is not taking the food the perculas bring him. His mouth is open slightly. I feel that if the anemone dies, the perculas will die also. <Not so, they will be fine.> I have to save them! <No worries.> I assume the problem is the hydroids because the sun coral is non toxic. <All corals have the ability to wage chemical warfare.> I have not used any chemicals in the tank since it was formed. I tested the water: 440 ppm calcium, NH 0, pH 8.1 alk Normal, NO3 0, NO2 .05. I am sure the NO2 are just a cycle. What can I do to get rid of the hydroids short of finding a sea dragon, Pteraeolidia ianthina. <Not really that east due to their size - you may have to extract the rocks they are on and remove the hydroids with tweezers.> I have not found a single supplier of them. <The sea dragon? Heavens no... these typically do very poorly in captivity.> If you can think of a single other reason for the eating habits of the Sebae please I am open for suggestions. <Consider more lighting.> My Sebae was a tank split and my tank mimics the conditions it was raised under. <Lighting as well? Most all anemones need intense lighting, and yours is likely not intense enough.> Please help.
--Hydroid Hater-Tonia
<Cheers, J -- >

Threaded Hydroid? 6/12/04
No emergency here, just trying to better understand my tank.
I have a nice, healthy Devils Hand (Lobophytum) that at night
puts out one or two relatively long (up to 7 inches) thin fibers that have "off-shoots" about a quarter inch long spaced at regular intervals.  It looks like a tank sized long line fishing rig.  
<yikes... this is not actually part of the leather coral, although it looks like it. I have a strong suspicion here. One of the threaded hydroids. Does this thing look like a barely discernable wisp of a thread... and the "branches" like teeth on a sparse/coarse comb?>
The fibers come out of one of the yellow fingers.  Is it trying to feed or is it a defense mechanism.  If the latter, should I avoid placing another coral within its reach?
<yes regardless... keep all other critters away. And if its a hydroid, watch your arm too... a nasty sting is possible>
Many thanks.  Your site has made a material contribution to my 38 gallon reef's growing success.
<no worries my friend... if this is a hydroid, it can be removed (and future ones can/should be screened by running all new livestock faithfully through a proper 4 week QT). Anthony>

Threaded Hydroid? II 6/12/04
Many thank you for the id Anthony.  I am not worthy of such expert advice.
<we are all on equal footing here my friend... as aquarists we each have our specialties, and we all evolve in time>
I only found one picture on the web that looks like it, the "sparse comb" you so aptly describe.  How shall I remove it? How about cutting off the finger it emerges from?
<no need to cut the leather, just look at the base and see if you can see ho well it is anchored (often appearing like a transparent fleshy plate/base in the case of this type)>
Will it move around the tank if I leave it?  
<not too motile>
After just 8 months with the reef, I am clearly in new territory here... Dan
<its all a learning process... no worries. Enjoy the journey. Anthony>

Stinging hydroids 6/15/04
Hi Guys
<cheers>
Wonder if you can help me. Are there any species of fish or invertebrate which would feed on stinging hydroids? I'm having difficulty controlling them in my tank. Thanks and regards
Adrian
<while there are many fishes and invertebrates that will control hydroids... they are not likely to safe with your other fishes and/or invertebrates (cnidarian feeding Chaetodontids, Asteroid sea stars, etc.). And if you could ID your species of hydroid and find a nudibranch, for example, that was an obligate predator... the nudibranch would soon starve. Your real solution is to get to the root of the problem (excess nutrients) and not focus on the symptom (hydroids flaring). Focus on starving them into submission and then polishing them off with a lite bit of manual control. Improve water changes, be more aggressive about skimming, increase water flow to get excess food/particulates exported rather than lingering to feed the hydroids, etc. Best of luck! Anthony>

Digitated Hydroids
Good afternoon crew,
<Good day>
I posed a question on the forums last week, and no one really had an answer for me. The only suggestion I got, was to email you all and see if you had any good info to share with me. Thank you for any assistance you may provide. Here is the original post from the Marine Invertebrate forum: 
Here is the situation: I currently have 5 of these nasty hydroids (digitated hydroids). Two of them extend to 4in. at night, two of them extend to 3in., and one of them to about an 1 1/2 inches. Of these five, I can reach 3 of them (one large, one medium and the small sized one). The other two are nestled deep into the back of my largest live rock, and there is no way I can get to them. Even if I was able to move all other LR and creatures off of it, they are in deep crevices that are barely wide enough to stick a nail in.
Here is my question (which you could probably guess.. hehe):
Does anyone have good experience with removing these type of hydroids? If so, what was your method? Also, I have had different hydroids in the past, not many but a few, and they generally cycled out within a couple weeks to a month. If you have had them before (the digitated kind), how long did it take for them to cycle out? I wouldn't even mind letting them just do that, except a few of them are getting way to close to some of my corals at night, when they extend themselves.
Current setup:
100g
30g sump/fuge (LV, 4in. LS, macro algae)
AquaC EV180
12x turnover
Magnum 350 canister (changed weekly with carbon)
100lb LV
Test readings:
NH3/NH4, NO2, NO3 = 0
pH = 8.3
Temp = 78 to 80
Ca = 400
ALK = 9 dKH
sg = 1.024
Kent sea salt, 10 to 15% weekly water change, no additives
<Erica, if it were me, I would get a syringe from the pharmacy and make up a strong solution of Kalkwasser and when the buggers are out, inject them with that. It should do the trick. James (Salty Dog)>