Strange worm living *inside* Acropora in a friend's tank.

[ColinCBN]

This worm is in a tank setup by a colleague of mine, so I don't have as much information about the tank as I would like. What I do know is that the tank is one month old and he has never done a water change. He has a great skimmer and a UV sterilizer so I guess the LFS that sold him the setup thought that was enough. Or he misunderstood their instructions, whatever, I'm working on that.

He already has two Acro frags in it, and I noticed this weird worm living inside one of them. This pic is not very good (old iPhone), but you can see the white calcareous tube coming out of the middle of the first branching near the base of the frag. When extended the worm looks like two sets of eyelashes connected to a central protrusion.
I thought it might be some kind of invasive barnacle, but it does not have the characteristic closing "shell" of all the barnacles I have seen, and it seems to be a more complex organism like a fan-worm.

I looked around the web at sites covering common pests etc. and have yet to see anything that looks to be the same creature.

I will try to get a shot of it extended (as soon as I pulled out the camera-phone the little s.o.b. retracted).

Any advice would be appreciated.

[reefjunkie42]

it looks like a vermilliad worm, you need to get a pair of bone cutters and cut the sps and pull out the worm, the coral will heal, try to kind of cut the "nub" out and the worm will be under the coral flesh

[reefjunkie42]

btw they spread and should be removed fast and sorry for the spelling i know i butchered it:)

[ColinCBN]

Sounds bad. Can you point me to any links with pics so I can show my friend? I think it will help him accept why I am taking a pair of pliers to his livestock ;)

[29reef]

Another solution is to place a ball of glue (2 part epoxy works great) over the opening. This normally kills the pest.

[ColinCBN]

Thanks for the replies.

This pic is bad to the point of uselessness, but at least he stayed open for it. I will try to get a better camera in a few hours.

Does anyone have a link to some info on these things? I want to go to my friend with as much ammo as I can. He still thinks everything the LFS says is true, and if they have said "Don't worry it's probably a Christmas tree worm", he is likely to believe them and let the thing spread.

[ColinCBN]

I got some slightly better pics of it. I am no photographer so they are still not perfect, but at least you can see what it generally looks like.

[tetra-tag]

If you are seeing a crown of feathers, or petals, it's probably just a filter feeder that settled out on that particular coral. If this is the case it isn't bothering the coral except in the area it has already overgrown, it is most likely not actively burrowing into the coral or feeding off coral tissue. I doubt that it can grow any faster than the coral in an aquarium setting, and will probably eventually die of starvation, and then overgrown by the coral.

(A Vermetid is actually a sessile snail that builds a tube and doesn't have a crown, usually the only thing visible is the strings of mucous which they use to filter food from the water column.
http://www.reefs.org/library/aquarium_net/0897/0897_8.html)

[ColinCBN]

Yes, it definately has a crown. It is hard to make out in the pics, but it is certainly there. When it retracts you can also tell the worm has burrowed into the coral. So-far the tissue around the tube does not seem to be dying out or anything, but if the worm spreads to other parts of the coral I might need to act.

It would be nice if this is a relatively harmless cohabitant, but it is on the short list for removal if it seems dangerous.

[reefjunkie42]

i am 99% positive its a bad hitchhiker, is it letting a "cob web" type thread out? if so it is def not good, and you should remove it in 1 or the 2 afore mentioned ways. hth

[ColinCBN]

It has not let out any cobweb looking threads. It looks a lot like a tiny feather duster worm, with two separated oblong crowns joined to a central bit. If you tap the glass (acrylic) it will retract, and then come out again in a minute or so.

If it was not for the fact that it has burrowed into a living coral it would be a cute little dude, but its choice of housing seems pretty suspicious to me.

[evsalty]

When in doubt yank it out.

[M007]

It has not let out any cobweb looking threads. It looks a lot like a tiny feather duster worm, with two separated oblong crowns joined to a central bit. If you tap the glass (acrylic) it will retract, and then come out again in a minute or so.

If it was not for the fact that it has burrowed into a living coral it would be a cute little dude, but its choice of housing seems pretty suspicious to me.

Filter feeder. Seen it before, have a couple, not a problem.

[abrian]

It sounds from the description like a harmless filter feeder, but if it bothers him to have it there, i would use the dab of superglue method to seal its tube and starve it out before I tried to cut it out. The acro will eventually overgrow the tube once it is dead.

[gasman059]

absolutely filter feeder no issues whatsoever.

[fq600]

I have the same deal with one of my acro. I didn't know what it was but noticed that the acro is not bother by it so I left it alone. It's clear white and looks like a filter feeder.

[Pallobi]

absolutely filter feeder no issues whatsoever.

agreed...

[rehab]

I have a bunch of these in my tanks. Definitely harmless as my corals will just grow over the tube and the worm will make new tube and the circle continue. It's what happened in nature so why change it when neither party is harmed.

[Pallobi]

When in doubt yank it out.

however, also agreed... lol :)

[gasman059]

there's no doubt here- more harm will come by trying to get rid of it.

[ColinCBN]

Thanks for all the replies. I will certainly not be trying to take cutting shears to a friends coral unless I know without a doubt that this thing is harmful. As it is the coral is not showing any necrosis or anything, so my first reaction is to wait, unless anyone has links to more info about these things and the research is conclusive they are bad.

That being said I will also be keeping a weather eye out for any more of these guys, and I'll be checking this one out everyday for any signs of damage to the hosting coral.

Again, thanks for the advice!

[colotl]

I got the same critter. Looks like black eye lashes going in and out. It's been on my coral for over a year with no problems

[mkbtank]

Leave it.

[coralnut99]

You will often see encrusting montis with these guys. I guess even with harmless stuff it will boil down to personal taste, but I love watching corals with these tiny featherdusters embedded. A little loser to real life I guess.

[dzhuo]

My guess would be a young Paguritta gracilipes.

[texgv]

I have a couple of those in my tank one at the base of my montipora undata and one on a clam shell, it's a filter feeder and represents no risk.

[sandhog]

I have one as well.I always wonderd if it was good or bad.I also see it expelling waste.I guess now I know.

[slapshot]

As stated above just put a little epoxy in/over the hole. Problem solved. Not really harmful but kind of unsightly.

[jbaeza83]

I have one in my acro that I just got, can someone let me know if this is the same thing?

http://youtu.be/QxTjRMoGl2Y?hd=1

[ColinCBN]

Looks similar. So far the one in my friend's tank has not caused any problems and the coral is doing fine. Great actually, lots of new growth.

The worm has not expanded or spread at all. Just a simple fan worm I guess. The tank is very lightly fed so I don't think the worm is getting much to eat, which may be a factor in it staying smallish and not propagating.

I can't tell 100% if the one in the video is the same, but the tube looks just like my friend's. If it is the same I would not worry too much about it.

[jbaeza83]

Thats good to hear, I will be keeping an eye on this just in case, lol. Thank you for the quick response Colin.

[lolgranny]

Another solution is to place a ball of glue (2 part epoxy works great) over the opening. This normally kills the pest.

+1, just take superglue gel and put it on the hole. Problem solved. Not a big issue whatsoever so dont fret :spin2: