Hydroids! - Please help!

[Psychedelic Mandarin]

Hello all!

We have had a bunch of digitate hydroids in our tank for the past 3-4 months but they seem to be multiplying rather quickly of late.

http://www.rshimek.com/images/scott%20curry%20hydroid.jpg


They are only visible at night when they extend out into the water. So far, they don't seem to bother anything, but Dr. Ron says that they pack a potent sting to corals. I have been using kalk paste to kill them (which is difficult at night) but many are difficult to reach since their base is often located under rocks, etc.

Here is a link to some info on Dr. Ron's site:

http://www.rshimek.com/odd_critters.htm#Regular%20Hydroid%20Jellyfish

Does anyone know of any natural predators for this type of hydroid? Does anyone have any information on what types of corals can be stung (our tank is mostly Acros)? Do they crash out on their own? These things are driving me crazy!

Any help would be greatly appreciated.

Thanks!

[kpebbles]

BUMP

[Psychedelic Mandarin]

^^

Am I the only one with these things?

You have to check for them at night, mine don't come out during the day at all.

[Sylock]

I had about 45 in my 10 gallon nano. I had to start pulling them out with twizzers.

[Psychedelic Mandarin]

Thanks for the reply Sylock!

If you didn't get the hydroid at the base, did it grow back?

Also, did you notice the "babies" at the base of some of them?

Thanks!

[Sylock]

You want to get as close to the base as you can. If you got say 2/3rd of the critter, it would come back. The 'babies' seem to get pulled up with the main. Be ready when you start though because if you don't pull it up, and just knock it around, it will retreat for the night (at least mine did). It also seemed that by the time I pulled 4 or 5, all the other ones retreated, almost like they were communicating some how.

[Psychedelic Mandarin]

Thanks again Sylock!

I've been doing a combination of kalking and manual removal. Unfortunately there are a few I can't get to.

Does anyone know of any natural controls? I added a few peppermint shrimps but I don't know yet if they touch them.

Also, what about hermits? When I used to keep hermits in the tank, they would just pick anything near them. Any chance they pick off these lousy things (or would that just spread them around)?

These must be more of us with these things. Any help would be GREATLY appreciated.

TIA

[jms]

Same problem bump

[Psychedelic Mandarin]

jms:

I've been meaning to post an update. I experimented with a bunch of things since my last post.

Here are a few things I have noticed. They are in my tank only in places that are not accessible to grazers. I have watched one of my turbo snails eat one. It was just grazing on some algae and then sucked one of the digitate hydroids right up. So I added the following to the tank:

- Some more snails (varied size, I figure some are more effective at getting to tight places)
- Peppermint Shrimp
- Blue Leg Hermits

So after lots of careful viewing, I have come to the conclusion that the peppermints were the most effective. In fact, my refugium was loaded with digitates so I put a peppermint down there. After 3 days, I could no longer find any! I will have to get him out of there eventually so he doesn't kill all the pods and worms. In terms of the Turbos, they only get the exposed ones....and most are usually tucked into some nook.

HTH

[TiGs]

peppermint shrimps did the trick, I have to remember that for next time. I took care of my finger hydroid infection by smoothering them in Kalk paste. Took me a week to hunt them all down. Peppermint shrimp would of saved me a lot of time.

[Leviathan]

Psychedelic Mandarin

I posted a thread a month or so ago, asking about theses little guys. I have done some reading on them and in most cases they are refered to as pests. I have at least 100 of them ( which only come out at night ) and have had them for some time. I have yet to see ANY negative effects at all from them.

In the thread I posted I asked if ANYONE could give me some factual data on them being an actuall problem and have yet to find any proof of them damaging anything.

Im not saying they are safe by any means, but I am starting to consider the idea that they might not be as harmfull as most think.

Have you noticed any actuall damage done to corals etc. by them?

Who knows they may end up being like bristle worms, and become perfectly acceptable in a reef system.

Or my theory may be totally off and it will be time to go on a seek & destroy mission.

Chris

[jms]

I've got a ton of them too and some that contantly touch various corals including montis and acros and have seen no damage.

BUT, from a search here and elswhere, there is a pervasive view that they pack a "serious sting".

ANY other views would be very helpful.

[jms]

Mine also only come out at night.

[Leviathan]

I've got a ton of them too and some that contantly touch various corals including montis and acros and have seen no damage.


This is exactly what I am saying, I have plenty that are touching and even growing near many sps/lps/softies & clams and they are all growing well and no recessions at all. In fact I had 2 that were growing near the base of a Monti. Dig. and it encrusted over them.


I just havent witnessed this "serious sting" that everyone keeps saying will happen.

[Psychedelic Mandarin]

You might be totally correct about this one. My corals retract when they are touched by the hydroids but I didn't see any damage to the tissue (that I could see by the naked eye). I was just trying to be safe, but who knows, I could have been stressed for no reason.

My info what based on what Dr. Ron said in some older posts. When my outbreak really got going, Dr. Ron was on vacation. Perhaps someone should start a thread on his forum now that he is back?


Originally posted by Leviathan
Psychedelic Mandarin

I posted a thread a month or so ago, asking about theses little guys. I have done some reading on them and in most cases they are refered to as pests. I have at least 100 of them ( which only come out at night ) and have had them for some time. I have yet to see ANY negative effects at all from them.

In the thread I posted I asked if ANYONE could give me some factual data on them being an actuall problem and have yet to find any proof of them damaging anything.

Im not saying they are safe by any means, but I am starting to consider the idea that they might not be as harmfull as most think.

Have you noticed any actuall damage done to corals etc. by them?

Who knows they may end up being like bristle worms, and become perfectly acceptable in a reef system.

Or my theory may be totally off and it will be time to go on a seek & destroy mission.

Chris

[Sylock]

Thanks for the update!

[Mad Scientist]

the name of the reef safe chemical used to kill these guys?

These guys are a major problem for seahorse keepers and some company used to have a product out there, but, I can't think of the name.

[jms]

I posted a reference in the good Doctor's forum, lets see whether there are additional comments.

[Leviathan]

Originally posted by jms
I posted a reference in the good Doctor's forum, lets see whether there are additional comments.

Though I take his comments into consideration, mostly all I have read by him on these creatures states they are dangerous. However as with most articles I have read on them stating this, there is little or no factual proof. Just data on their stinging abilities, I have yet to see a visible rep. of them damaging another inhabitant.

If its ture I would love to see the evidence.

[JHardman]

Originally posted by Leviathan
Though I take his comments into consideration, mostly all I have read by him on these creatures states they are dangerous. However as with most articles I have read on them stating this, there is little or no factual proof. Just data on their stinging abilities, I have yet to see a visible rep. of them damaging another inhabitant.

If its ture I would love to see the evidence.

Well it's not a scientific study... But recently I got a medusa form in one of my grow out tanks with some ~45 day old A. Ocellaris fry in it. I spotted the medusa because a couple of the fry "jumped" about an inch straight up and sped off. I siphoned out the medusa. That night I had three dead fry. These three are the only losses since day 7 of that hatch and no more since that day. I can only assume that they were stung to death. I do water changes from the brood stock system and normally filter the water with a 53µm sieve, but I was in a hurry that day... :rolleyes:

I can also tell you that the medusa interfere with at least one of my adult pairs during feedings. The medusa "smell" food in the water and come to the same area where the fish are being fed, and wham the fish get stung. They learn pretty quickly that the food floating in the water is painful and tend to eat only off the bottom now. Which is less than optimal for saturation feeding of spawning clownfish.

Short of pulling all the LR from my system and boiling it I haven't found a good way to kill these things. I wish I knew of something that ate them that I could put in with my clownfish pairs. But in all of the searches/posts I have made I haven't found a solid answer yet.

[Leviathan]

JHardman,

Thanks for the info on your personal experience with them.


I am not completely convinced either way at the moment. But I am with you on finding a natural predation way of ridding them, if they turn out to actually be a dangerous creature.

[kpebbles]

JHardman & Leviathan,

Have you guys tried using peppermint shrimps for the hydroids? Myself & Psych Mandarin were able to rid ourselves of almost all the digitate hydroids that way. It's definitely worth a try if these hydroids are harmful pests.

Good luck!

[JHardman]

Originally posted by kpebbles
JHardman & Leviathan,

Have you guys tried using peppermint shrimps for the hydroids? Myself & Psych Mandarin were able to rid ourselves of almost all the digitate hydroids that way. It's definitely worth a try if these hydroids are harmful pests.

Good luck!

Do you have a species name for the shrimp? Common names get applied to so many different species it hard to tell for sure which one you are talking about.

I wouldn't call them harmful, at least in my brood stock system, they are just one more thing that keeps my pairs focused on something other than spawning and eating enough (critical to spawning)... I am hesitant to add shrimp to the brood stock tanks as they are notorious egg eaters, but if they would wipe out the hydroids once and for all, I would live with some wiped out nests. In the grow out tanks, yes I think they are a deadly problem, but I can filter the water so it is really not a problem unless I get stupid again.

[JPerkins]

Lymsata Wurdemanni would be the proper name for Peppermint Shrimp.

Lymsata Ambionesis are camelbacks, look like peppermints sorta, and not reef friendly.

[pperez]

I recently killed what i think were hydroids. I simply used kalk paste over them. They were spreading so fast that i needed to try something. Well kalk definately kills them. Overnight the shrimps cleaned out the dead ones so the rocks are nice and clean. The ones i got look similar to the picture in the The reef aquarium vol 2, pg 431.

I did notice that they came in direct contact with my staghorn and i saw no noticeable damage. So i don't know about that powerful sting theory. Still i wasn't about to take a chance, so death to them.

[Psychedelic Mandarin]

Lymsata Wurdemanni is correct. That is the one that I used for my digitate hydroids. I don't know if they are effective against other types of hydroids.

A bit of warning: although most call the Peppermint Shrimp reef safe, they are not that safe in my experience. They will kill feather dusters, will sometime pick at clams, will even kill a snail of two that has flipped over. So add these guys with caution. You might want to do a search on them before adding.

From what I hear (not from experience), the Camel-backs (Lymsata Ambionesis) are much worse and are totally not reef safe.

In terms of kalk paste. It works as long as you can get to it. I had a few that were either inaccessible or rooted deep in the rock that I could not get. I kalked the h** out of some of the deep rooted ones, only to have it pop out the next day. Obviously I couldn't get the paste deep enough in the rock. If you are lucky and they are attached superficially, I would think that manual removal and/or kalk paste would be the best course.

HTH

[jlserr]

Ok, i have these digitate hydroids, I have a couple of lysmata wurdemani and one lysmata amboinensis.

I had thousands of these hydroids 5 months ago (as my two lysmata wurdemani) and 4 months ago the amboinensis.

i've noticed now i have about just 50 or less d hydroids. I don't know if my wurdemanni did the job or maybe it's just a coincidence, but the hydroids, as the shrimps are in my tank 5 months ago, it's a lot of time.

so far, lysmata amboinensis is not the camel shrimp, it's the cleaner shrimp and it's more safe than the wurdemani, i saw one of my wurdemani cuting the polyps of my torch coral (euphyllia glabrescens) lasta night.

I'll take a look tonight if my wurdemani are eating the d. hydroids, they might be doing the job.

See you

[KevinM]

Originally posted by Leviathan
Im not saying they are safe by any means, but I am starting to consider the idea that they might not be as harmfull as most think.
Have you noticed any actuall damage done to corals etc. by them?
Who knows they may end up being like bristle worms, and become perfectly acceptable in a reef system.
Or my theory may be totally off and it will be time to go on a seek & destroy mission.
Chris

Since someone revived this thread today, I'll post my recent experience with them.
I mounted several SPS frags a few days ago, and last night I noticed one of the pieces of rubble had a Hydroid on it about an inch long. It's able to reach 1/2" up onto the frag. Direct contact between the hydroid and the polyps on the Acro produces no visible reaction from either. I'll snap some pics, and keep an eye on it for a couple weeks. But so far it's not been an issue.

FWIW
Kev

[Leviathan]

KevinM

I am keeping a steady eye on the ones I have as well, especially thoses in close contact with corals. As of yet I have seen no harmfull reaction at all.

[hwyman]

well guys its been a while how are the hydriods doing around your coral? We got a small outbreak and have yet to see adverse effects on the coral. Some are right next to the coral so I dont want to kalk balst them. As for peppermint shrimp clearing them up, our peppermint shrimp wont touch them. Heard of coral beuties doing it, but no proof.

http://www.ohrberg.org/angela_web/htdocs_staging/pictures/tank/new/star2.jpg

Found this picture in ask dr ron the hydroid is right in the coral with no adverse effect.

[Peter Eichler]

I've had all types of hydroids throughout the years and have yet to see them harm anything with a sting. The photosynthetic varieties can certainly be a pest in some cases though as they can spread like wildfire in the right circumstances, and the right circumstances are usually a well setup reef.

I wouldn't worry yourselves much about hydroids stinging other inhabitants, as I'm sure many of you have witnessed by now the deadly nature of their sting seems to be highly exagerated. And I believe when authors refer to hydroids as having powerful stings, it's most often in reference to Millepora aka Fire Coral, which is a hydrozoan and does have a powerful sting. However some authors seem to have confused this <cough Sprung cough> and lump all hydrozoans together in the "powerful sting" category, when it is clear than many are pretty harmless.

[Leviathan]

I have actually seen a decress in their presence in my 75 gallon since my last post. Even now I have seen no adverse effects at all on surrounding corals.

[James56]

I had hydriods and they stung everything. It was so bad. they were all over. I just got rid of the rock and bought new ones.

[bastion666]

I have a new tank and started to see what I am sure were colonies of hydroids. All were clustered together and spread throughout the tank.

I bought a couple peppermint shrimp to deal with a few apitasia that wouldn't die via hot water, and they also cleaned out every hydriod in sight.

The good news is (so far) that they have left the fether deusters and other corals alone.

Just another data point.

[hwyman]

Got our coral Beauty. YES IT DOES EAT DIGATATE HYDROIDS!!
have seen a drastic decrease in the number of them in the tank.
I think it may have nipped at some of our xenia coral but has left the rest alone for now. Going to monitor it around the coral, if it starts to eat it we will get rid of it.But it picks at the rock and gravel all day. None of the other fish will do that. I think he was a good addition to the tank....if he leaves the coral be.

[Foster]

aaah! I have hundreds of these in my 225. I have notice that a large one (about 4") has cause 1 branch of a a.millipora to bleach from contant contact!

What seems to work best for eraticating these? I have 350+lbs of LR, so replacing it is out oif the question.

[BillnJennh]

I have a few of these type of hydroids very near an open brain with absolutely no adverse affects. The hydroids brush against the flesh of the open brain when it's fully inflated, and I haven't noticed any recession of the brain at all. They don't seem to be harming anything, so I think I'll put my vote in for the "not as harmful as thought".

[Stevan]

I'm resurecting this for further discussion.

Only thing I've noticed since my outbreak began is that I have almost no Pods these days. Coincidence maybe.

[kewliz]

This is an interesting thread. I hope people respond.

I recently noticed 2 or 3 of these in my tank. They're all on a specific rock, and it's my Gramma Basslett's fave rock, and it's pretty, so I'm not getting rid of it. I'm thinking of just sticking a small piece of epoxy over their hole to see if it kills them. Has anyone thought to try this? It would be hard to grab them with tweezers- my tank is deep, and I have a feeling if I pull the rock up, these things will withdraw.

I also wonder if a freshwater dip might get them out. It might be worth a try.

Anyone else have anything to add?
Anything you've tried, whether successfully or unsuccessfully?

[jimroth]

I am experimenting with getting rid of myrionemia (sp) hydroids, my plague. They are the ones that look like dandelions, they are tan and photosynthetic. I have in the past tried to get a seaslug which would eat them (bad idea). Recently I have been reading Scott Michael's new butterfly fish book and he states that several 'flys' eat hydroids. I picked up a yellow longnose butterfly, and I'm watching him closely....

[Stevan]

Originally posted by kewliz
This is an interesting thread. I hope people respond.

I recently noticed 2 or 3 of these in my tank. They're all on a specific rock, and it's my Gramma Basslett's fave rock, and it's pretty, so I'm not getting rid of it. I'm thinking of just sticking a small piece of epoxy over their hole to see if it kills them. Has anyone thought to try this? It would be hard to grab them with tweezers- my tank is deep, and I have a feeling if I pull the rock up, these things will withdraw.

I also wonder if a freshwater dip might get them out. It might be worth a try.

Anyone else have anything to add?
Anything you've tried, whether successfully or unsuccessfully?

I just took the worst rock out and did a 3 min or so dip in RO/DI...All gone.

I think the Pepps are doing in the others.

[kewliz]

I wish I'd done a freshwater dip with mine. I just put a tiny ball of epoxy on top of the hole that it was in. Unfortunately, that specific rock is under another one, so I have yet to view the results. When we re-stack again, I will check it and freshwater dip.

[TiGs]

Originally posted by jimroth
I am experimenting with getting rid of myrionemia (sp) hydroids, my plague. They are the ones that look like dandelions, they are tan and photosynthetic. I have in the past tried to get a seaslug which would eat them (bad idea). Recently I have been reading Scott Michael's new butterfly fish book and he states that several 'flys' eat hydroids. I picked up a yellow longnose butterfly, and I'm watching him closely....

Used kalk paste to eradicate them and the digitate hydroids. To this date they never came back.

[surfy]

I have always had digitate hydroids in my tanks and have never had any problems. I have a bunch of them right now in my sps tank and have seen no bad side effects as of yet.
There is too many for me to sit there and siphon each and every single one out so I just leave them be.

I do try to keep my clams clear from them but other than that I have corals right next to or very close to them.

[impur]

Just wanted to update this a bit. I noticed 2 digitate hydroids about 5 inches long in my tank last night. I had previously rid my only known one by supergluing all around the rock. Luckily is was in a small rock with a few zoos attached. I tried a 10 min RO/iodine dip with no effect. Of the 2 i saw last night, one was brushing up against a small SPS frag that recently started growing well. Since i saw it touch the frag last night the coral has not extended polyps. I don't see any damage, but this is abnormal for that frag. I'm going to try the kalk paste this weekend.

[JollyGreen]

I too have had the digitate hydroids for the last 3-5 months, setup my tank about a year ago. Anyway, they definitely grow fast in my tank, and they do sting my corals. Xenia don't seem to be bothered by them, but I have a acropora millepora which gets stung by them and at the very least they cause it to receed when stung. I also have a torch coral that get stung by them and it also receeds when stung

Whenever I see them in the tank near a coral I immediately tweezer them out, so I'm not sure if prolonged stings kill tissue, but I don't want to find out, maybe someone with more money can do that test.

I bought a peppermint trying to get rid of these things and it appears to have not touched any of them, and I don't think it's bothered any corals either. I might try another one this weekend, some people say some peppermints eat hydroids/aiptasia and some don't.

I'll probably try the coral beauty too, but probably sometime in January.

I am definitely putting these on the harmful side!

JG

[SDguy]

I have these in my tank. They definitely irritate zoa's, making them close, and making their skirts shrink. A new tricolor A. valida frag shows tissue recession at the exact point where a digitate hydroid was touching it. Maybe coincidence, but I'm not thinking it is. I'm still weighing my options, as to how I will control these things.