Colonial Hydroids

[fatoldsun]

Ok, so last night I searched (here and elsewhere) and read until my eyes were crossed. And I'm pretty sure I'm more confused than when I started

I'm setting up a new 90g tank with a 40g sump/fuge. While that cycles I have a 55 that's been running for several months. I bought almost everything (the 55 & 90 tanks, livestock, LR, and some other dry goods) from someone who had to move for a job. I set up the 55 to keep about half the LR, a couple fish and other stuff in water that came with the tanks. I kept the 90 broken down so I could build a different stand and upgrade some of the dry goods. The remaining rock was kept in a 35g drum of sw with a powerhead and a couple heaters while I did all of this. Shortly after I took over the 55 I noticed what I thought were feather dusters. Being REALLY new to SW I thought ' cool, I must be doing something right because any new life must be good, right? WRONG! Now they're all over. Not sure I want to move them into my pristine new setup and let them spread again.

Here's what I'm talking about

Here's shot a shot of a different piece of rock.
You can make out the fake feather duster looking things.

No one seems to think there are any natural predators for the colonial hydroids. Some things will just mow off the tops but the worm retreats and builds a new tube. Ok, so if there are no good predators, are they good or bad and how do you get rid of them? To say there's disagreement on this is the understatement of the year. Ranging from: They're the spawn of the devil... to: They're not bad and will disappear in a year as the tank gets established...

How to get rid of them. This ranged from use a blow torch "“ the loss of bacteria on the good parts will be inconsequential; to "“use a hammer and chisel; use crazy glue gel to entomb the worms in their tubes; use kalk paste (or salt paste, or Joe's Juice made into paste, or lemon juice followed by a spray of boiling water [I'm still not sure how to spot spray boiling water). Someone said they pulled all the infected rock out and have it sun-tanning in the yard. Some have boiled the rock. Some have let it dry out completely.


I feel like I have a ton of these. They just pop up and in that thank there seem to be some on every rock. The 55 is probably not a great environment to control stuff "“ there's a HOB filter and that's it. Like I said this is a temporary set up. So I have this unique opportunity to try and do something about these before the rocks get moved into their new home. Should I bother? Should I bake and or boil the rocks? Spot hit them with a torch and assume if I miss a couple the new tank will be less hospitable to them? Should I put them in a drum with water and a heater and a powerhead and let them sit with no light or food for a couple months (try to starve them) Or should I completely dry and then re-cycle the rocks. I know these are pests that many have dealt with so should I take advantage of the idea that I have to take the rock out of the 55 anyway and can choose how/when it goes back into a tank?

 

[Daimyo68]

Hard to tell with your pics, but I only see one possible colony of Hydroids, in the second picture, a little in and up from the bottom right. The long tubes look more like spaghetti worms/feather dusters. They will help clean the water, as they extend what looks like spider webs at random times, and they catch debris flowing in the water. I have several of these in my tank, and they have never harmed anything.

Here's an article (no need to read the entire thing), about 1/3 of the way down the page are pictures of actual hydriods.
http://reefkeeping.com/issues/2004-10/sp/feature/index.php

Its weird that you posted this also, because just yesterday, I was removing hydriods from a rock in my tank. Hydriods burrow down into the rock, and the way I try to get rid of them is to use my fraggin kit and actually chip away at the area they are on.

They seem to come back, so obviously i'm not getting them all, but they don't grow fast, and the last time I had to do anything with them was a year ago. I've thought about pulling the rock out and "cooking" it, but I have a couple acro's that are well established on the rock.

 

[disc1]

Those look like vermetid snails. Most likely if you leave them alone they will subside. If they keep going everywhere you can try superglue over the end of the tubes or manually breaking them off. Neither is 100%, but having a few vermetids isn't really bad. I've also heard that a yellow coris wrasse will eat them, but I haven't seen this for myself.

 

[sczlars]

+1 on vermetid snails. I've found that if I crack them open with a sharp pointy knife, my cleaner shrimp will come and munch the innards.

Personally I think they are cool; another odd critter in the tank with interesting behavior. I just don't want too many of them.

 

[fatoldsun]

+1 on vermetid snails. I've found that if I crack them open with a sharp pointy knife, my cleaner shrimp will come and munch the innards.

FUNNY!

Ok, thanks guys I'm kind of relieved, the more I read and research (and I posted on my local club’s board as well) it seems that I'm not even sure what these are - others are also saying they are vermetid snails - I thought I had one of those too
here's a shot

they are different looking, what I thought was the snail has more of a snail's shell in appearance - texture, color, sheen, etc...and it's coiled as opposed to these other things which are white and chalky looking and shooting straight up. At least one looks like a little feather duster so not the web that I thought the snails had but they do seem to have the “coil” base and I guess hydroids burrow straight down into the rock and open to look more like a duster and most importantly, seem to colonize in clumps – so I’m really not sure what I have.
Nothing like the big gamble – do I put them in the new tank and chance it or do I waste all that good bacteria and other associated like and nuke ‘em….. I guess that decision is still up in the air but I think I will take a small rock and torch it to see how it reacts and how they react when I put it back in the 55 – one rock at a time b/c I don’t want any ammonia spikes in there. I have one snail that made the move with the tank – not sure what kind, but it has 2 growing on its shell – I guess that suggests vermetids more than hydroids since the shell wouldn’t leave much room for burrowing.
And yes, if I accept that they are vermetid snails than I have to assume that I have a variety of them but since snails are one of the most abundant and prolific organisms on the planet I suppose that’s not so unusual. I guess if someone reads this and believes these are hydroids, PLEASE suggest that you think they are because I hope to avoid making a big mistake if I can and the way I see it, adding any pests is bad but killing half of my rock is bad too
Oh, for what it's worth, I also read somewhere that a certain type of bumble bee snail will eat them - the guy who posted this never came back with pics or a follow up tho....

 

[disc1]

I would put that rock in my tank.

 

[fatoldsun]

I tried to take some more pics - hopefully they're vermetid snails - I know it's really hard to tell in a pic and even harder when the camera is a phone but I figured in this instance (before I risk adding this to the new tank) the more opinions, the better....

as far as what the pics don't "show"... the tubes are hard - calcified so to speak and they do seem to put out a web like leader which fits the description of the snails. Only a handful look anything like feather dusters but those that do, the tubes look the same. Also, from what I found about the hydroids, they tend to pop up in patches - these are on about every rock but fairly spread out and random.

 

[disc1]

About the only real way to tell a vermetid from a feather duster is to see the duster come out. The vermetids won't always put out a web, only if there's food floating around in the water. When I used to get algae on the glass they would go crazy after I cleaned it off and all that stuff got into the water.

That being said, it's most likely one or the other. Neither is a reason to throw away a rock.