Hydroids! - Please help!

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.

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 Hydroid Jellyfish

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!
 
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!
 
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.
 
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:

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
 
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.
 
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
 
Hydroids

Hydroids

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.
 
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.
 
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?


Leviathan said:
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
 
Does anyone know....

Does anyone know....

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.
 
I posted a reference in the good Doctor's forum, lets see whether there are additional comments.
 
jms said:
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.
 
Leviathan said:
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 53Ã"šÃ‚µm 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.
 
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