How to defeat hydroids??

[jlinzmaier]

Hello.

I've recently noticed some tiny, brown, anemone/zoanthid-looking little critters. The are growing in thick little mats in what is now several areas. I've done some research and I'm pretty sure they're Brown Hydroid Myrionema's.

In a reef tank, are there any great ways of ridding the tank of them other than manual removal?? Unfortunately they are located quite close to several corals and attached to rocks that I cannot remove to scrape them off. Will scraping at them simply split them and encourage the growth of their numbers like it does with mojano's and aptasia??

Thanks.

Jeremy

[bubbly]

Hydroids are quite the scourge -- I have two types that are not myrionemas but are still very annoying . Some people say that putting aquamend putty over them for a while is effective, b/c even if you scrape them off, they burrow into the rock and can grow back.

Others have said that an emerald crab has been helpful in controlling them. Can you post a pic of your hydroids?

[jlinzmaier]

<a href=showthread.php?s=&postid=15587289#post15587289 target=_blank>Originally posted</a> by bubbly
Can you post a pic of your hydroids?

I'll get a pic posted tomorrow. No time tonight.

Thanks.

Jeremy

[jlinzmaier]

Here are a few pics. The second pic shows some with their tentacles retracted into their little tubes. Until I took these pics I didn't realize they had such distinguished little tubes. Maybe scraping them off won't be so bad. I've got a forecepts that should work well for this little endeavor. They're so small that I'm sure it'll take several rounds of scraping and crushing before their truly gone.

http://img139.imageshack.us/img139/6343/1005437.jpg

http://img139.imageshack.us/img139/3093/1005438.jpg



Jeremy

[CLINTOS]

I had those in my tank they have a some what of a soft tube I used a paring knife and carved them off digging into the L.R carving a batch at a time I also used a hard bristle brush

best to use a seperate pail of tank water when brushing/carving/rinsing

[perrl]

Emerald crabs took care of mine.

[jlinzmaier]

As you can see I'm also battling bubble algea so I'm going to try another round of emerald crabs. They didn't help last time but I've been manually removing the larger bubble and hopefully they'll be interested in eating the small bubbles since there is no other algea growing. Maybe I'll get lucky and they'll keep the hydroids in check also. I do plan to take some time to scrape some off before they get too bad. They are already limiting some polyp ext on some of the zoas and palys.

Thanks for the replies everyone.

Jeremy

[jlinzmaier]

<a href=showthread.php?s=&postid=15592848#post15592848 target=_blank>Originally posted</a> by CLINTOS
I had those in my tank they have a some what of a soft tube I used a paring knife and carved them off digging into the L.R carving a batch at a time I also used a hard bristle brush

best to use a seperate pail of tank water when brushing/carving/rinsing

I just spent about 20 minutes scraping off what I could. Your exactly right about their soft flexible tube. By looking at them I assumed they would be similar to vermetid snails and I would easily be able to crush them - not the case at all. They have a stalk very much like a tube worm and they seem to be embedded into the rock making it a bit more difficult. They can't just be plucked off. I gouged out what I could in an attempt to get every last bit. It wasn't as bad as I thought and the areas where I have noticed them I was able to pull out the rock to scrape and swish in a separate container.

We'll see if they come right back or if I did an OK job at really getting them scraped out. An interesting experience so far. They have yet to take over my tank anyway.

This seems like the type of critter a CBB would love to pick at. Wish I had one to find out!! I guess if I had one and it was eating the hydroids, I probably wouldn't have even noticed I had the hydroids. For the longest time I just thought they were some sort of very small brown little polyp growing until I noticed polyp retraction of the corals they were touching.

Jeremy

[Agu]

Covering them with epoxy putty has worked for me. Looks kinda ugly until the coraline over grows the putty but it beats the alternative of letting them spread.

[CLINTOS]

I look at them like aiptasia you want to always pick up your rocks and investigate to be sure occasionally every month to be on the safe side

it took me 3 years to fully get rid of aiptasia because it spread for a year and I didn't know about it

If u have time keep looking up coral pests and irritants along with planning a quarantine tank if u have a large tank/system

[unbreakable]

do they hurt corals? i have some on a small rock right next to an SPS frag thats already encrusting and finally branching out. if i try epoxy next to the frag im afraid it might damage it some how

[Nereaga]

Added an atlantic pygmy angel and he wiped them out in a week, never have they returned... good argi! :)

Brad

[jlinzmaier]

<a href=showthread.php?s=&postid=15594749#post15594749 target=_blank>Originally posted</a> by unbreakable
do they hurt corals? i have some on a small rock right next to an SPS frag thats already encrusting and finally branching out. if i try epoxy next to the frag im afraid it might damage it some how

Yes, they'll irritate/harm corals. In the areas where they are touching, the corals will show polyp retraction, lack of tissue expansion (LPS), and likely eventually tissue loss (mine killed a few zoanthid polyps). They do have a potent sting.

Jeremy